iBlog

INTRODUCTION

Imaging from the worst place on Earth? Possibly!

Welcome to my image blog from Lancashire, UK. Living in Lancashire does make imaging a challenge. Our incessant damp cloudy weather is legendary and coupled with light pollution probably as bright as can be found anywhere (I am 15 miles NW of the centre of Manchester) makes for testing times! Add to that flight path one with constant aeroplanes, which is why it has been suggested as possibly the worst place on Earth for imaging.

But there is some good news. With modern light pollution filters we can still produce excellent results - at least when the clouds clear - but of course it's not easy. It would be so much simpler to log onto a robotic rent-a-scope and let them take the image for us. But if you are up for the challenge and the achievement of taking your own images, with your own equipment, in your own back garden, then I hope the following offers some encouragement. Yes it's difficult but we can do it.

I often shoot the luminance and the colour simultaneously - there are not enough clear spells to allow the luxury of shooting separately. Shooting LRGB with one telescope would take years! So two telescopes and two cameras was the obvious solution . Also necessary is having a dome slot wide enough for both to have a clear line of sight. The luminance is usually taken with the RCOS + Apogee Alta and the colour with the Takahashi + Canon DSLR. Despite their disparate focal lengths this works reasonably well as my current Canon has 4.3 micron pixels (plate scale 2 arcsecs/pixel) and the Apogee 18 micron ones when binned 2x2 (plate scale 1.3 arcsecs/pixel). I find binning essential to maximise signal and improve the signal-to-noise ratio.

The images are all taken from my back garden and appear in order of me processing them - we have plenty of cloudy nights for that. I use a combination of IRIS and Maxim for processing with final tweaks in Photoshop. To get rid of the light pollution takes much trial and error. IRIS scores here with several options but processing often comprises many nights work - certainly always longer than the actual taking. The exception are images taken with an h-alpha filter which is a superb light pollution filter. It also permits imaging with strong Moonlight present - isn't it funny how it always seems to be clear at full Moon!

 

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20th JULY 2015

NGC 5005, (Caldwell 29)

 

A spiral galaxy with a small bar and classed as a LINER, somewhat similar to Seyfert galaxies (Viegas-Aldrovandi & Gruenwald, 1990). LINER stands for Low-Ionisation Nuclear Emission-line Region and was devised by Hechman (1980) to describe a new class of emitting region in the nuclei of galaxies. The existence of a LINER in the galactic nucleus is related to the presence of a compact nuclear radio source. The source of the emission of LINERS could be from the ionising radiation caused by massive stars (called “warmers”) or from the accretion disc around a black hole. The latter seems to be more in favour.

Paul Eskridge et al. (2002) described this galaxy in detail "Appearance—SBa: System is fairly inclined. Bright, elliptical bulge with a flattened nuclear source. Bulge is threaded by a bar with a P.A. skewed 30 from that of the bulge. The outer bulge isophotes are boxy, and the bar crosses the diagonal of the bulge. There are two ansae near the ends of the bar. Two very narrow spiral arms. The inner arms have some evidence for star-forming knots and are quite open. However, the outer arms tighten and appear to wrap several times around the system. The outer disk shows an occasional knot, but there is no coherent star-forming pattern associated with the outer arms".

Kazushi Sakamoto et al. (2000) studied the gas dynamics of NGC 5005 in detail - see their figure 8 to the right.

Another Caldwell object for which I needed a better image but nights were getting too light so only a short exposure. The faint dwarf galaxy towards the top edge (north) is PGC166157. This was my last image before the summer shut down.

Image Details

  • Dates: 26th April 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: 4 hours total: Luminance - 13 x 10 mins - RGB 13 x 10 mins (Tak)
Diagram
Diagram copyright Sakamoto et al., 2000.
Note UHR = ultra-harmonic resonance.
NGC 5005

NGC 5005



 

8th JULY 2015

Saturn - altitude 18 degrees

 

A much more severe test of whether the ADC I had built last winter would work. Well it certainly has cancelled out the atmopheric dispersion - no adjustment of the colour planes was needed for this image. However, it cannot (unfortunately) cancel out the mushy Lancashire atmosphere! Still it's an image at an altitude where really nothing much can be expected. Roll on Mars at 15 degrees altitude next year.

Image Details

  • Dates: 4th July 2015
  • Telescope: Celestron Celestar 8-inch SCT @ f/20 with ADC unit set to 36mm prism spacing.
  • Camera: Microsoft Lifecam Webcam
  • Exposure: 1000 frames of a 1500 frame video shot at 10 fps.
   
Saturn
Saturn 2015


5th JULY 2015

The Draco Trio, NGC 5981, 5982 & 5985

 

Appearances can be deceptive - probably not a true trio at all. The redshifts for these 3 galaxies pose questions as to their proximity to each other:-

NGC 5981: redshift velocity = 1894 km/sec
NGC 5982: redshift velocity = 3046 km/sec
NGC 5985: redshift velocity = 2694 km/sec

Probably NGC 5982 and NGC 5985 form a wide non-interacting physical pair but NGC 5981 is more likely not associated and nearer to us. NGC 5982 & 5985 are probably around 115 million lightyears with NGC 5981 probably well under the hundred mark.

Edge-on spiral NGC 5981 is slightly disturbed and asymmetric. The inner disc is tilted against the outer disc and the bulge component is furthermore slightly tilted against the inner disc.

NGC5982 is an elliptical shell galaxy with regular major axis shells (Sikkema et al. 2007). This galaxy harbours a Kinematically Decoupled Core (KDC: Wagner et al. 1988), and probably a rotating central disk (Emsellem et al. 2004). Outside the core, the galaxy is slowly rotating (Emsellem et al. 2004).

Face-on spiral NGC 5985 has thin and well defined arms and perhaps a short bar.

I had taken a luminace image 6 years ago but had no colour information. As I was returning (at last) for colour I took the opportunity to take more luminance as well.

Image Details

  • Dates: 12th May 2009 and 22nd April 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: 6 hours total: Luminance - 23 x 10 mins - RGB 13 x 10 mins (Tak)
Draco Trio

Draco Trio



21st JUNE 2015

Caldwell 36 and X7 (Galaxy NGC 4559)

 

Galaxy Caldwell 36 or NGC 4559 is classed SAB(rs)cd. It is inclined at 67°to our line of sight and is around 30 million light years away.

When I wrote "Observing the Caldwell Objects" in 1999, I reported that several x-ray sources had been observed in NGC 4559 by Vogler et al., 1997. Aside from the (expected) one at its centre the next brightest, denoted X7, was located in an odd position, way out near the western edge of the galaxy. Since then the story has moved on with further observations by Soria et al., 2005 of the ultra-luminous x-ray (ULX) sources in NGC4559. Using Hubble images they were able to search the error box where X7 was located - the dotted box in the top inset in the image below. Vogler et al. had thought it must be from a 100 year old supernova, but Soria found that a black hole of around 50 solar masses accreting material from a 20 solar mass companion fitted the data better. The trigger for the formation of this huge black hole and companion they believed was an interaction with a dwarf galaxy (g in the inset). Soria et al. stated they would do further observations to check if the galaxy g was associated with Ngc 4559. So far I can find no published confirmation and, rather worryingly, this galaxy does look very small and therefore remote!

In 2012, the story got a bit more complicated. A possible supernova was discovered just south-east of X7. It turned out to be a Luminous Blue Variable (LBV) and it flared again in 2014. It seems to have been relatively quiet when I imaged it and also when Hubble imaged it. Perhaps it will flare again in 2016?

Image Details

  • Dates: 20th & 21st April 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: 7.5 hours total: IDAS-P2 -11 x 20 mins - RGB 21x 10 mins (Tak)
N4559

NGC 4559



 

14th JUNE 2015

Venus - shot using ADC

 

With the observatory shut for the summer, It was time to try out the ADC I had built last winter. Venus was a tempting target and its white colour would be a good test to see if atmospheric dispersion could be cancelled out - any false colour should be immediately apparent. It was at around 21 degrees elevation so the prisms were set to a spacing of 30mm. The image below has had no re-alignment of the colour planes and is a stack of 4000 images - no selection of best frames took place. So first signs are encouraging.

Image Details

  • Dates: 10th June 2015
  • Telescope: Celestron Celestar 8-inch SCT @ f/20 with ADC unit
  • Camera: Microsoft Lifecam Webcam
  • Exposure: All 4000 frames of a video at 30 fps.
   
Venus
Venus 2015


7th JUNE 2015

Galaxy NGC 4449, Caldwell 21

 

At last a galaxy perhaps worthy of its inclusion in the Caldwell Catalogue!

NGC 4449 is located 12.5 million light-years from Earth and is a member of a relatively nearby group of galaxies in the constellation Canes Venatici. It is classed as a dwarf galaxy and is very similar in size and morphology to one of the Milky Way's satellite galaxies, the Large Magellanic Cloud.

It is famous for its starburst activity and it seems that gravitational interaction with a merging galaxy has probably disturbed the gas in the main galaxy and caused the burst in star formation. Evidence for this interaction is the tidal or stellar stream (at about 7:00 o' clock in the images) that was first detected as a mysterious faint smudge in digitized photographic plates from the Digitized Sky Survey project. It is also visible in images from the Sloan Digital Sky Survey.

Authors of a recent study led by David Martínez-Delgado of the Max Planck Institute for Astronomy in Heidelberg, called it a stealth merger, where an infalling satellite galaxy is nearly undetectable by conventional means, yet has a substantial influence on its host galaxy.

I was surprised that just 7 x 20 minute exposures were enough to record the tidal stream despite being labelled as "nearly undetectable by conventional means". The Subaru image actually resolves both into their individual stars.

Image Details

  • Dates: 17th April 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: 5 hours total: IDAS-P2 - 7 x 20 mins - RGB 14 x 10 mins (Tak)

Subaru
Image taken with the Subaru 8.2 metre telescope showing the tidal or stellar stream.

NGC3636

NGC 4449



31st MAY 2015

Galaxy NGC 3626, Caldwell 40

 

Again not a very spectacular object to warrant inclusion in the Caldwell Catalogue but it is a typical lenticular galaxy. Its fame (and its inclusion no doubt) is due to the fact that its gas orbits in one direction whilst its stars go in the opposite direction. It is around 65 million light years away and is on the outskirts of the Leo II Group of galaxies.

NGC 3626 is a large galaxy which has a huge amount of extended Hi gas which counterrotates to the stars. This is thought to as a result of a recent merger and this was recently confirmed by O. K. Sil’chenko et al., 2010. According to Friedli & Benz (1993) who studied this scenario, the initially counterrotating gas begins to inflow because of a bar and forms a stable highly inclined ring near the center due to resonance effects.

Though classified as SO/SA (non-barred), NGC 3626's large-scale structure reveals multi-tiered stellar disks and an inner oval disk. Therefore, O. K. Sil’chenko et al. suggest that the bar was present some time ago, but has now dissolved, or almost dissolved. The current star-forming ring in NGC 3626 may then be related to the resonance of this dissolving bar. O. K. Sil’chenko et al. explained this "The whole scenario of the galaxy transformations from spirals into lenticulars may include the following sequence of related events: first, a minor merger occurs, then the acquired gas and stars inflow to the center, the large-scale stellar disks develop bars and are heated, and the gas is compressed near the center and exhausted by the intense induced star formation. After a few billion years, we have typical lenticular galaxies, except for their unrelaxed gas behavior. Within such a scenario, the main mechanism of the lenticular galaxy formation is gravitational and not at all related to the intragroup hot medium impact". In the case of NGC 3626, they suggest its transformation from spiral to lenticular took place about 1 to 2 billion years ago.

Image Details

  • Dates: 14th April 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: 5 hours total: IDAS-P2 - 7 x 20 mins - RGB 14 x 10 mins (Tak)


 

NGC3636

NGC 3626



24th MAY 2015

NGC 4725 & LoTr5, Widefield

 

An amazing combination which shows clearly the huge apparent size of the planetary nebula, Lotr5. NGC 4725 is probably the biggest and best galaxy omitted from both the Messier and Caldwell catalogues. The distorted galaxy above the yellow/red bright star is NGC 4747.

I had taken the widefield shot last year and although Lotr5 was there, it was far too faint to have done it justice. So with this year's deep image of the planetary nebula I was able to put the two together and finish the job.

Image Details

  • Dates: 18th April 2014, 9th & 12th April 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: 16 hours total

NGC4725-Lotr5

NGC 4725 & LoTr5



17th MAY 2015

LoTr5, Planetary Nebula

 

A British discovery! Examining plates taken with the 1.2 metre UK Schmidt Telescope in 1980, Longmore and Tritton identified 11 new planetary nebula candidates of which this was number 5 - hence its catchy name of LoTr5.

Longmore & Tritton's description: "This is a very large very faint non-uniform disc, slightly brighter towards the centre. Two members of a distant group or cluster of galaxies can be seen through the nebula. It has been confirmed as a planetary nebula from a spectrum taken by David Allen using the IPCS on the AAT. The lines of [O m] II 4959, 5007 were seen, very weak after an 800-s exposure. It is the highest galactic latitude planetary known. The star SAO 82570 = HD 112313 = BD + 2602405, at a (1950) 12h 53m 07s.76, d (1950) 260 09' 44".3 is positioned at the centre of the nebula within reasonable measurement error. Its spectral type (from the SAO Catalogue) is G5, mpg = 9.5, mv = 8.7. Thus if the nebula is associated with the G5 star the latter probably has a hot dwarf companion".

They were right - the bright G star is much too cool to illuminate the nebula and does indeed have a very hot dwarf binary companion responsible for the PN. This companion star is one of the hottest known in the range 120,000 to 185,000 degrees. The cool G star is rapidly rotating and close to break-up. It is also barium rich making a very odd combination. Ref: Thevenin & Jasniewicx, 1997.

Set as a challenge by Owen Brazell, this planetary is large but faint and required 11 hours worth of exposures to record it. However, that OIII signal may make it visible to the big Dob boys. It is located close to NGC 4725.

Image Details

  • Dates: 9th & 12th April 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: 11 hours total: OIII - 17 x 20 mins - RGB 30 x 10 mins (Tak)
 

LoTr5 discovery

The discovery image taken with the UK 1.2 metre Schmidt and spotted by Longmore & Tritton (1980). The small blob at 11:00 o'clock is a background galaxy.

 

Lotr5

LoTr5



7th MAY 2015

Palomar 4, Globular Cluster

 

One of the Milky Way's most remote globular clusters - further away than our satellite galaxies the Magellanic Clouds. Until very recently is was the second most remote known. However, a very distant object at 145 kpc, PSOJ174.0675-10.8774, or Crater, was recently discovered simultaneously in two independent surveys (Laevens et al. 2014; Belokurov et al. 2014). As yet it has not been confirmed as a globular cluster so Pal4 is the second most remote at least for a bit longer.

The most recent research paper on Palomar 4 is by Akram Hasani Zonoozi, Hosein Haghi, Andreas H.W. Kuepper, Holger Baumgardt, Matthias J. Frank, Pavel Kroupa in 2014. A. Kuepper summarised their results: "By looking at the distribution of masses of stars within the cluster and their distance from the center of the cluster, we see that Palomar 4 must have been born as a very extended ball of stars and – and that’s the surprising discovery – with a very odd configuration for the masses of the stars. Massive stars must have been much more abundant in Palomar 4 than in young star clusters we observe today. And these massive stars must have preferentially been closer to the cluster center. It is not obvious why a globular cluster like Palomar 4 should have been born with an overabundance of high-mass stars, with a segregation of massive stars towards the cluster center, and with a very large extent. Models of star formation and cluster formation will have to explain this result".

Image Details

  • Dates: 22nd, 23rd & 26th March 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: Luminance - 13 x 20 mins IDAS-P2 - RGB 28 x 10 mins (Tak)
 

Properties (Frank et al., 2012)

Age: 11±1 billion years

Distance: 102± 2.4 kpc  333,000 light years (note this is lower than previous estimates of around 356,000 lys)

Half-light radius = 18.4 ± 2.0 pc  60 light years

Total mass = 29800 ± 800 solar masses

Brightest Star: 18th magnitude


 

Pal 4

Pal 4



28th APRIL 2015

Holmberg 124 (Galaxy Group NGC 2805)

 

Holmberg 124 is a group of four interacting galaxies: NGC 2805, NGC 2814, NGC 2820 and Markarian 108 at a distance of 90 million light years.

The most recent research paper for this group is by Mishra et al. 2013. They analised Hi 21cm data from the Giant Metrewave Radio Telescope (GMRT). They detected spectral line emission from all the four galaxies and noted several signatures of tidal interactions among the member galaxies. The results for the northern triplet (namely NGC 2820, NGC 2814 and Mrk 108) confirm the earlier results of Kantharia et al. (2005) - see diagram right. They also reported possible detection of small discrete clouds between NGC 2820 and NGC 2805 which might be stripped Hi in the intragroup medium (IGrM). The Hi distribution of NGC 2805 is asymmetric with peak Hi column densities seen along the southern spiral arm and along a northern arc. Vigorous star formation has been observed along the southern spiral arm of NGC 2805.

They also supported the scenario given by Kantharia et al. (2005) that both tidal interactions and ram pressure are currently playing a role in the evolution of the triplet galaxies. From the observed northern Hi arc and extensive star formation in the southern spiral arm of NGC 2805 and additionally the systemic velocities of the four galaxies, they suggest ram pressure effects are also playing a role in the evolution of NGC 2805. They believe interaction with the IGrM would have triggered star formation in the southern spiral arm. This model for NGC 2805 succeeds in explaining the compressed Hi in the north, widespread star formation and the diffuse Hi detected in the south/south-west of the optical galaxy.

Image Details

  • Dates: 21st March 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: Luminance - 10 x 20 mins IDAS-P2 - RGB 20 x 10 mins (Tak)
 

Holmmberg 124
Figure 10 from "GMRT observations of the group Holmberg 124: Evolution by tidal forces and ram pressure?" - N. G. Kantharia et al. (2005). Note they hedged their bets on which direction NGC 2805 was actually moving! It is however the best diagram I found for explaining what is going on in this system. It is not to scale though.
Note IGrM = intra-group medium

 

Holmberg 124

Holmberg 124



19th APRIL 2015

Galaxy NGC 2775, Caldwell 48

 

Not one of the best Caldwell Objects - it's hard to understand why this very ordinary galaxy was chosen. There was a supernova discovered in it in 1993 just about when the Caldwell Catalogue must have been compiled so I guess that's the likely reason.

Although classified as a spiral galaxy (Sa) and viewed almost face-on, it has no prominent spiral arms or dark lanes. This is the reason for it being visually rather featureless. What appears to have happened is that this spiral galaxy turned its star making inter-stellar material into stars very early in its life. Proof of this can be found in its spectrum, which is characterised by the presence of absorption lines rather than by emission features more typical of spirals with prominent arms and star forming regions. This is particularly noticeable in the Calcium H and K lines. NGC 2775’s spectrum is therefore dominated by the light from old cool stars, which themselves are characterised by absorption, not emission lines. This is more common in elliptical or SO type galaxies. It therefore has a smoothish appearance with faint spiral arms and little star formation now taking place.

Just above (north of) NGC 2775 there is a tiny background group of 4 or 5 galaxies.

Image Details

  • Dates: 18th March 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: Luminance - 10 x 20 mins IDAS-P2 - RGB 15 x 10 mins (Tak)
 

 

NGC 2775
H I   2
UGC 4820
PGC 25861

Catalogue position for epoch J2000.0
Right ascension:  09h 10m 20.5s
Declination:          +7° 02' 19"

Constellation: Cancer

Object information:
Magnitude: 10.1
Size: 5.0’ x 4.0'
Position angle: 155°
Object classification: Sa      
NGC Description:   considerably bright, considerably large, very gradually very suddenly much brighter towards the middle, resolvable - mottled
Note: in group with NGC2777 and NGC2773

 

NGC 2775

NGC 2775



7th APRIL 2015

Born Again Planetary Nebula, Abell 30

 

Very easy to locate, just south-east of the Beehive Cluster in Cancer but boy is it faint. The detail is in the OIII band but my camer's senstivity is very poor here. I could have done with running longer but after 5 nights I decided enough was enough.

Headlined by Nasa as the "Born Again Planetary Nebula" in the press release accompanying their iamge (right) in 2012. In reality most planetary nebulae go through several ejection phases so why, when this one was discovered to have had 2 discrete events it was such a big deal - who knows? The Born Again name actually seems to originate with Wesson et al in 2003 and Nasa just latched on to it.

In the Nasa/ESA image (right) they have reversed the colours. Hydrogen is blue and Oxygen is red. Until I found this out I couldn't come to terms with what my image was showing!!!!

Image Details

  • Dates: 16th & 21st February, 13th, 14th & 17th March 2015
  • Telescope: RCOS 12.5 inch at f/9
  • Camera: Apogee Alta U9
  • Exposure: 8 hours total: Ha - 11 x 20 mins, OIII - 13 x 20 mins
 

nasa-eas

abell13

Abell 30



15th MARCH 2015

Planetary Nebula Abell 13

 

Appropriately numbered no. 13 - this object took 3 nights and 4 different filters to record it! According to Frew et al. (2012) "A catalogue of integrated H fluxes for 1,258 Galactic planetary nebulae" this PN is strongest in NII rather than in H-alpha. An ultra-narrowband H-alpha filter is not therefore ideal but one that includes NII as well will do best. The central star is catalogued as magnitude 18.8. However, it appears to be predominantly violet in colour as it did not record either with the OIII or H-alpha filters - I had to shoot an extra sequence of luminance images with a filter (IDAS-P2) passing violet in order to record it. I guess this will be a difficult object visually as there was litte OIII and H-beta will probably be weak.

Type of object: Planetary nebula PK 204-8.1
RA (J2000.0): 06h 04m 48.0s Dec (J2000.0): +3° 57' 00"
Constellation: Orion
Magnitude: 15.3
Size: 2.9'x2.2'
Magnitude of central star: 18.8

Image Details

  • Dates: 6th, 16th, & 21st February 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: Ha - 10 x 20 mins, OIII - 4 x 20 mins, IDAS-P2 - 4 x 20mins (RCOS); RGB (UHC filter) - 20 x 10 mins (Tak)
 

 

abell13

Abell 13



 

22nd FEBRUARY 2015

Planetary Nebula HaWe 2 (Sh2-200)

 

This object was catalogued by Sharpless as SH2-200 probably on the basis of the fainter outer (red) halo but it is in all probability a planetary nebula. This was first recognised by Hartl & Weinberger in 1987 in their paper "Planetary Nebula of low surface brightness: Gleanings from the POSS". It was no2 in their list so its name is generally abbreviated to HaWe 2. Their description is as follows:

No. 2 (138 + 04°1) : This object, listed as Sharpless 200, appears as a relatively large, slightly deformed ring in E (Blue), fainter and more disk-like in 0 (Red). Most remarkably, there appears to be an extended halo around the PN with a diameter six times as large as the central nebula ; note that the halo's size would then amount to 0.4, that is 4 pc at a distance of 580 pc ! The brightest part in the south- east of the halo has a red surface brightness of only ---- 24715. Although there is no visible blue central star, we suggest that this is a PN due to its enormous brightness in OIII according to the Emission Line Survey of Parker et at (1979) ; the halo, however, is not detectable there. A detailed study of nebula and halo is needed.

This object is faint and despite taking four years to get luminance and colour I still don't really have enough signal to do it justice.

Image Details

  • Dates: 11th January 2011 & 1st February 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: HaHaGB with Luminance and R, Ha - 8 x 20 mins, GB - 20 x 10 mins
 

 

Sh200

HaWe2



 

8th FEBRUARY 2015

Planetary Nebula Kahoutek K2-1 (PK 173-5.1)
Fleur de Lys Nebula(?)

 

Another object brought to my attention by the big Dob boys - this time by Owen Brazell. He had seen this nebula several years ago and thought it would make a good a target. It was categorised as "status not clear" by Zijlstra et al. (1990A&AS...82..273Z). However, It has a strong OIII signal so is, in all probability, a planetary nebula. It does though have a very untypical appearance. If I was prone to naming objects then perhaps the Fleur de Lys Nebula would be apt. It is located in Auriga and its magnitude is given as 12 - it is surprisingly bright. The magnitude of its central star is given as 18.2 or 18.8 depending on which catalogue you consult.

This object deserves to be better known but for some reason some catalogues record its position incorrectly. Both Skymap and The_Sky6 plot this object in the wrong position so if you load a DSS image to check it out then nothing is visible. I guess many must have been put off looking for it by this error.

Kahoutek is, of course, best remembered for his (in)famous comet for which spectacular things were predicted. The reality was somewhat disappointing and a very insignificant comet was actually observed. In later years Kohoutek worked in observatories in Spain and Chile specialising in planetary nebulae.

Image Details

  • Dates: 18th January 2015
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: Luminance OIII - 9 x 20 mins, RGB - 18 x 10 mins
 

 

K2-1

K2-1



 

1st FEBRUARY 2015

M38 and Abell 9

 

Brought to my attention by Andrew Robertson, who was struggling to see this faint planetary nebula with his big Dobsonians. This image was subsequently posted on the Deep Sky Forum by Owen Brazell to see if anyone had succeeded visually and if so, with what aperture. It is pretty faint and the OIII is weak so visually it will be a very tough target.

Little published information for this planetary nebula (PK 172+ 0.1) and about all I could find is

Magnitude Nebula: 18.9
Magnitude Central Star: 23.5

It was also flagged up as a "possible" planetary nebula as if there was some doubt. However, in my image at least, it looks like a planetary nebula so Abell was right to include it. It is amazing he spotted something so small and faint.

Image Details

  • Dates: 30th December 2014
  • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
  • Camera: Apogee Alta U9 and Canon 60D
  • Exposure: Luminance Ha - 13 x 20 mins, RGB - 26 x 10 mins
 

 

M38

M38 and Abell9



 

22nd JANUARY 2015

Comet Lovejoy (C/2014 Q2)

Switched to a much wider field of view and broader light pollution filter. The clouds cleared quite late so shot when past the meridian and low so quite a bit of light pollution to remove.

Image details:

  • Date: 18th January 2015
  • Telescope: Pentax 50mm lens at f/4 and Bolton Tracker
  • Camera: Canon 40D
  • Exposure: 17 x 5 mins with IDAS-P1 filter
  • Lovejoy

    Comet Lovejoy


     

    20th JANUARY 2015

    Comet Lovejoy (C/2014 Q2)

    With just a short period forecast between clouds I didn't have much time to prepare for this image. I underestimated the tail length and used the wrong filter. The Tak was already loaded with a UHC clip filter for my next target and is not ideal - hopeless really - for comets. I should have switched to the 200mm lens and a broadband LPR filter. In the end I got just under an hour before the clouds returned.

    Image details:

  • Date: 16th January 2015
  • Telescope: Takahashi FSQ106N
  • Camera: Canon 60D
  • Exposure: 11 x 5 mins with UHC filter
  • Lovejoy

    Comet Lovejoy


     

    11th JANUARY 2015

    Sharpless Sh2-187

     

    This young star formation/ HII region is most likely ionised by a B0 class star (star 4 - see right) and is surrounded by a 4600 solar mass molecular cloud. It is partially obscured by the Lynds dark nebula LDN 1317 and contains the infrared star cluster BDS2003. (Ref: Galaxy Map). It has its own "trapezium" - stars 4, 5, 6 & 7 (see right).

    The definitive research into this object was carried out by Joncas, Durand and Roger (1992) and they concluded:

    1. Star 4 was probably the ionising star.

    2. Sh187 is 100,000 to 200,000 years old.

    3. We are actually only observing visually about 3% of the HII present.

    4. There is an HI disassociation area around the HII region.

    5. Sh187 resides in relatively "quiet" area of the local arm with no supernova remnants or OB associations.

    6. It could eventually produce massive stars.

    Located in Cassiopeia but not the brightest of Sharpless objects so I pressed on imaging for 5 hours. Only 152 Sharpless Objects still to do!

    Image Details

    • Dates: 3rd & 5th December 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: Luminance - 15 x 20 mins, RGB - 30 x 10 mins
     

    fig1

    Figure 1: Joncas, Durand & Roger, 1992 - Central region with star 4 believed to be the ionising star of the nebula.

    Sh187
    Sh2-187

     

    4th JANUARY 2015

    Dwarf Galaxy, IC 1613

     

    IC 1613 (Caldwell 51) is an irregular dwarf galaxy in the constellation Cetus just below the star 26 Ceti. It was discovered in 1906 by Max Wolf

    IC 1613 belongs to the Local Group and is approximately 2.3 million light years distant. This is slightly nearer than M31 and is possibly a satellite of it. In 1928 Water Baade recognized this galaxy as a member of the Local Group because it could be resolved into individual stars using the Mount Wilson 100" reflecting telescope. He also could find no bright globular clusters and this is still true today.

    Its importance lies in the calibration of the Cepheid variable period luminosity relationship for estimating distances as it has many of these variables.

    If you suffer from light pollution, then this is one of most difficult of galaxies to image - its very low surface brightness and low altitude mean it is never going to be spectacular for us. However, there is a slight suggestion of a bar running 2:00 o'clock to 8:00 o'clock. In the top right hand corner of my image is a short trail of the asteroid Sara (533) at magnitude 14.8.

    Image Details

    • Dates: 27th & 30th November 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: Luminance - 9 x 20 mins, RGB - 19 x 10 mins
     

     

    IC1613
    IC 1613

     

    DECEMBER 20th, 2014

    The Skull Nebula, NGC 246

     

    Discovered by William Herschel in 1785, NGC 246 is located in Cetus and never gets very high in the UK.

    Its central star is actually a blue and yellow close double which I have just about managed to resolve. Presumably the blue one is the real central star and the yellow one just a line of sight pair. The blue one seems to be fading fast. In 1930 it was 9th magnitude, by 1969 it was down to 11.2 and today it has dropped to around 12th magnitude. It is one of the hottest stars known at 200,000 degrees.

    The central star is speeding through space at about 86 kilometers per second and as a result the material expelled from it piles up in front and spreads out behind it. The direction of the star's motion was determined by Hipparcos as 0.023 arcsec/year to the west (right). This has resulted in a definite oval shape. The leading edge is the brightest and closest to the star where it interacts, and is slowed down by, the inter-stellar medium. Whereas the trailing side is much more diffuse and somewhat transparent - see Figure 1 (right) by Muthu & Pottasch, 2000.

    Image Details

    • Date: 23rd November 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: Luminance - 8 x 20 minutes; RGB - 16 x 10 mins
     

    Muthu

    Cass A
    NGC 246

     

    DECEMBER 13th, 2014

    Cassiopeia A Supernova Remnant

     

    Cass A is the last (known) supernova in our galaxy and it should have been visible from Earth around 1671. Amazingly there are no historical records of any sightings of it. There is a slight possibility that it was recorded as a sixth magnitude star 3 Cassiopeiae by John Flamsteed on August 16, 1680. Possible explanations lean toward the idea that the source star was unusually massive and had previously ejected much of its outer layers. These outer layers would have cloaked the star and reabsorbed much of the light released as the inner star collapsed.

    Its name comes from the fact that it is the brightest extrasolar radio source in Cassiopeia - in fact it is the brightest in the sky - or at least it was. Its flux is decreasing so it won't hold this record for much longer.

    Recently (2008), Krause et al. obtained an optical spectrum of the Cassiopeia A supernova near maximum brightness, obtained from observations of a scattered light echo - more than three centuries after the direct light of the explosion swept past Earth. The spectrum shows that Cassiopeia A was a type IIb supernova and originated from the collapse of the helium core of a red supergiant that had lost most of its hydrogen envelope prior to exploding.

    I started off with an h-alpha filter which recorded faint material to the north of Cass A but not much of the remnant itself. Not sure what elements were causing the main nebula to shine I switched to a luminance filter with maximum passbands - the IDAS P2 filter. This recorded the remnant much better so I kept going with this filter over several nights to get a total of 5 hours.

    Image Details

    • Dates: 14th, 17th, 18th, 19th & 23rd November 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: Total 11.5 hours: Luminance - 5 hours, H-alpha - 2.5 hours, RGB - 4 hours
     

     

    Cass A
    Cass A

     

    DECEMBER 6th, 2014

    Dwarf Planet, ERIS

     

    Eris is the most massive known dwarf planet in the Solar System and the ninth most massive body orbiting the Sun. Its mass is 27% more than Pluto although their diameters appear very similar - about 2300 km. As of 2014, its distance from the Sun is 96.4 astronomical units - roughly three times that of Pluto. Its orbit is very eccentric and inclined pointing to an encounter with Neptune in the early days of the solar system. It has one known moon, Dysnomia and it is its orbit that has enabled the precise derivation of Eris's mass.

    Eris was discovered by the team of Mike Brown, Chad Trujillo, and David Rabinowitz on 5th January 2005, from images taken on 21st October 2003. The discovery was announced on 29th July 2005, the same day as Makemake and two days after Haumea, due in part to events that would later lead to controversy about the latter. The search team had been systematically scanning for large outer Solar System bodies for several years, and had been involved in the discovery of several other large Trans Neptunian Objects (TNOs), including Quaoar, Orcus, and Sedna.

    The team had also discovered Haumea but were awaiting more observations when a Spanish team announced its discovery. It later emerged that the Spanish team had accessed the Brown team's data so the actual discoverer of Haumea has never been officially ratified but left blank.

    Eris's magnitude at the time of my images: 18.7

    The galaxy dead centre is PGC 1072733 with a redshift of 0.018866 and magnitude 15.83.

    Image Details

    • Dates: 14th & 18th November 2014
    • Telescope: RCOS 12.5 inch at f/9
    • Camera: Apogee Alta U9
    • Exposure: RCOS 2 x 10 mins with IDAS filter
     

    Eris Orbit NASA

    NHC6934
    ERIS

     

    NOVEMBER 30th, 2014

    Open Cluster, NGC 663 (Caldwell 10)

     

    Cassiopeia is full of spectacular open clusters and NGC 663 is definitely one of the best! I "discovered" this cluster over 40 years ago when sweeping Cassiopeia with binoculars - it stands out much more than the nearby M103. One of the best Caldwell objects for binoculars or small telescopes and one that doesn't need pristine dark skies.

    It is a very young cluster at 31 million years old but quite distant at around 6800 light years. A much studied cluster or at least the Be type stars within it are. A very recent paper by Yu et al. (2014) found/confirmed 34 Be stars. However, despite what is often reported, NGC 663 does not have an abnormally high proportion of this type. In fact they found that they represented only 3.5% which is lower than other clusters they compared it to.

    Image Details

    • Dates: 12th November 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: RCOS 12 x 5 mins with IDAS filter. Tak 12 x 5 mins with UHC filter.
     

     

    NHC663
    NGC 663

     

    NOVEMBER 30th, 2014

    Open Cluster, NGC 559 (Caldwell 8)

     

    Cassiopeia is full of spectacular open clusters but NGC 559 is probably not one of them! It is, however, an interesting cluster and well worth searching out. Note the prominent white stars are most likely foreground objects and not part of the cluster.

    It is very reddened making its age and distance somewhat tricky to work out. When I wrote Observing the Caldwell Objects in 1999, it was thought to be very old (1.3 billion years) and relatively near by (400 light years) but subsequent research by Ann and Lee (2002) has changed that. It is now believed to younger at 400 million years but much further away at around 7500 light years. So the reddening of the cluster is more down to distance than extreme age.

    Image Details

    • Dates: 12th November 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: RCOS 13 x 5 mins with IDAS filter. Tak 13 x 5 mins with UHC filter.
     

     

    NHC559
    NGC 559

     

    NOVEMBER 19th, 2014

    Globular Cluster, NGC 6934 (Caldwell 47)

     

    The other globular cluster in Delphinus. It is one of the least studied globular clusters in the northern hemisphere and it was not until 1973 that the first colour-magnitude (CM) diagram for it was produced. This was derived by Harris & Racine, the former is of course better known today for his definitive catalogue Globular Clusters in the Milky Way (1996/7). The distance to the cluster was determined using both the CM diagram and by studying the periods and luminosity for 31 RR Lyrae variables known in the cluster. The distance to the cluster they determined to be about 50,000 light years - fairly remote but no where near as remote as NGC 7006.

    More recent research by Piotto et al. (1999) used Hubble Space Telescope observations of the central region of NGC 6934 where they found many blue straggler stars (BSS). Using observations of over 8,000 stars they were able to calculate a deeper CM diagram plus the luminosity function. From these, they were able to derive the cluster's age, which they placed in the range of 13 to 16 billion years. Since then the age of the universe has been determined to be 13.75 billion years so perhaps the cluster's age is most likely to be 13 billion years.

    I wasn't planning on a short exposure but clouds rolled in twice. This was all I got over 2 nights and I had to wait 32 days for the second clear spell! For curiosity I processed what I had to see just what was possible.

    Image Details

    • Dates: 11th October & 12th November 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: RCOS 2 x 10 mins with IDAS filter. Tak 3mins with UHC filter.
     

     

    NHC6934
    NGC 6934

     

    NOVEMBER 8th, 2014

    Remote Globular Cluster, NGC 7006 (Caldwell 42)

     

    Located in Delphinus, NGC 7006 is largely ignored by amateur astronomers as its visual appearance, in all but the largest Dobsonian, is very under-whelming. It is one of those objects that is more interesting when bit of background knowledge is learnt. NGC 7006 resides in the halo outside of the main disk of the Milky Way. Currently it is 135 000 light-years away and is one of most remote known. This is almost as far as our satellite galaxies, the Magellanic Clouds. In fact its orbit is so eccentric that at its farthest it will be more remote than these galaxies. That eccentric orbit is best explained by it having formed as part of a dwarf galaxy which was subsequently absorbed by the Milky Way.

    Also in the image are several background galaxies. Redshifts indicate distances of 380,000 to 560,000 light years.

    Image Details

    • Dates: 10th October 2014
    • Telescope: RCOS 12.5 inch at f/9 and Takahashi FSQ106N
    • Camera: Apogee Alta U9 and Canon 60D
    • Exposure: RCOS 14 x 10 mins with IDAS filter. Tak 14 x 10 mins UHC filter.
     

     

    NGC7006
    NGC 7006

     

    OCTOBER 26th, 2014

    The Blue Snowball Nebula, NGC 7662, (Caldwell 22)

     

    The forgotten planetary nebula of autumn. It's just as bright as its popular neighbours, M27 and M57 so why not seek it out? It is its spectacular colour that makes it worth viewing. Many books call it aquamarine but blue is good enough for us in Lancashire.

    NGC7662 is a triple-shell nebula with a bright inner shell (18" x 12") enveloped by a outer shell (30" x 27") and surrounded by a faint spherical halo 134′′ in diameter (Chu, Jacoby, & Arendt 1987). The inner shell appears as a bright rim. In contrast, the outer shell appears as an envelope attached to the inner shell. A feature of the outer shell is the presence of FLIERs or“fast low-ionization emission regions.” These are just visible in my image as brighter pinkish patches. To see them in their glory then the Hubble Telescope is needed.

    What shape is it in 3D? Guerrero et a l. resolved this in 2005, decalring that both the inner shell and the outermost layer of the outer shell can be modeled as an "expanding prolate ellipsoidal shells with the northeast end of the major axis tilted toward us". So now you know.

    Image Details

    • Dates: 4th & 6th October 2014
    • Telescope: RCOS 12.5 inch at f/9
    • Camera: Apogee Alta U9
    • Exposure: H-alpha - 125 mins, OIII - 120 mins, Luminance - 30 mins
     

     

    NGC7662
    Blue Snowball Nebula

     

    OCTOBER 12th, 2014

    The Saturn Nebula, NGC 7009, (Caldwell 55)

     

    Discovered by William Herschel in 1782 with his 18.7 inch telescope in Aquarius. He observed it several times at up to 932x magnification - don't try this at home! However, it is a small nebula and without magnification it looks like a star. It was Lord Rosse who gave it its name. He must have been able to see the ring like extensions on either side (ansae) that resemble Saturn when edge on. These are difficult to see and it took Lord Rosse with his giant 6 foot telescope to see them.

    Research: The following is by Profesor Jim Kaler. The hot (90,000 Kelvin), blue, 13th magnitude star at the centre is the old nuclear-burning core of what was once an extended giant star, while the surrounding nebula is the inner part of the star's lost envelope that has been structured by the remaining star's hot wind. The distance is not well known. If at 2000 light years, the nebula is 3/4 of a light year long. The central star seems faint to us only because of its distance and because the vast majority of its radiation comes out as energetic ultraviolet light. In reality, the star thousands of times more luminous than the Sun. Still heating at constant luminosity, the star will eventually cool and dim to become one of the many white dwarfs that dot the cosmos. The ansae, called "FLIERS," are high-speed jets shot out of the central star, probably along the star's polar axis. While NGC 7009's are the most prominent, they are seen in a number of nebulae, notably NGC 3242, NGC 6543, and NGC 2371- 2.

    The central star is not easy to record and it took a separate luminiance exposure to show it (just) - neither H-alpha or the OIII recorded it obviously due to it being brightest in the UV.

    Image Details

    • Dates: 22nd September and 1st, 2nd October 2014
    • Telescope: RCOS 12.5 inch at f/9
    • Camera: Apogee Alta U9
    • Exposure: H-alpha - 70 mins, OIII - 160 mins, Luminance - 30 mins
     

     

    NGC7009
    Saturn Nebula

     

    SEPTEMBER 21st, 2014

    Gamma Gygni Nebula, IC 1318A, B & C

    The Gamma Cygni Nebula consists of a large complex of several emission areas separated by dark rifts. Gamma Cygni is the bright star just above middle and is actually not part of the nebula - it is in the foreground and located about half way between us and the nebula. Classed as an F type star so it should appear yellowish although many imagers show it blue. Here, we are looking deep into the Orion Arm of our Galaxy with the nebula more than 3000 light years away from us

    Also prominent in the image is the Crescent nebula (NGC 6888) energised by a Wolf-Rayet star. The original h-alpha image also records the extremely faint Soap Bubble nebula.

    Image details:

  • Date: 2nd, 7th and 9th September 2014
  • Telescope: Canon 200mm lens
  • Camera: Canon 60D
  • Exposure: 4 hours total with UHC filter (at f4.5) and H-alpha filter (at f/2.8).
  • GamCyg

    Gamma Cygni Nebula


     

    SEPTEMBER 14th, 2014

    The Little Cocoon Nebula, Sh2-82

     

    This combination HII emission region and blue reflection nebula (also called LBN 129 and DG 159) is ionised by the B0.5V star HD 231616. Appearance-wise, it does have a great deal in common with the real Cocoon Nebula (IC5146) and hence its semi-official name of Little Cocoon Nebula. With the current distance estimate of 3500 light years, it appears to be near the Vulpecula OB4 association although it is actually in Sagitta, not far from the Coathanger asterism.

    Research data for this object is limited but there is one professional paper "A multiwavelength study of the star forming H II region Sh2-82" by Nai-Ping Yu and Jun-Jie Wang (2012). They found the nebula contains 2 molecular clumps both containing many Young Strellar Objects (YSOs).

    The bright star to the east (left) is mag 7.47, type K0, and makes imaging a bit tricky. Watch out for ghost reflections that can look like new comets!

    Image Details

    • Dates: 26th & 28th August 2014
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 60D.
    • Exposure: RCOS H-alpha filter 11 x 20 minutes + 16 x 10 minutes RGB UHC filter (60D)
     

     

    Sh2-82
    Little Cocoon

     

    AUGUST 12th, 2014

    Tadpoles in IC 410

     

    I had taken the H-alpha image way back in 2009 but never got around to taking the colour. When checking oustanding jobs during the summer break, I realised that I had actually taken the colour information last winter so I have combined the two at long last.

    The bright emission nebula IC 410 lies about 12,000 light-years away in the constellation Auriga. The nebula of mainly hydrogen gas and is over 100 light-years across. Its complex structure is sculpted by stellar winds and radiation pressure from the embedded very young open star cluster NGC 1893 (centre-left). This formed in the interstellar cloud only around 4 million years ago and that radiation pressure from it has created two relatively dense streamers of material trailing away from star cluster's centre. These are the famous "tadploes" and are about 10 light-years long.

    Image Details

    • Dates:January 2009 and 2013
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 40D.
    • Exposure: Luminance h-alpha filter 10 x 10 minutes (RCOS) + 14 x 10 minutes RGB UHC filter (40D)
     

     

    Ic410
    Tadpoles in IC410

     

    JUNE 29th, 2014

    A Draco Duo - Galaxies NGC 5905 & 5908

     

    A contrasting pair of spiral galaxies - one face-on (NGC5905) and one edge-on (NGC 5908). Both are around 160 million light years distant so may be an associated pair. NGC 5905 is classed as SB(r)b ie a barred spiral with ring (see below). NGC 5908 is classed as Sb (see below).

    NGC 5905: Nuclear rings are viewed as a type of starburst, consisting of distinct compact areas of young massive stars near the centres of spiral galaxies. These starbursts are attributed to a star formation rate (SFR) that significantly exceeds the average found among normal galaxies. They can dominate the overall star formation in early Hubble type barred spiral galaxies and dramatically alter the structure of the host galaxy. Typically located within the central kiloparsec, nuclear rings contain a mixture of neutral and ionized gas and dust. The great majority of nuclear rings are found in barred spiral galaxies, where the bar provides essential fuel for the formation and evolution of the ring via shock-induced channeling of disk gas to the nuclear regions. Reference: A Connection between star formation in nuclear rings and their host galaxies - Mazzuca et al., 2008.

    NGC 5908: The central bulge is small enough to put the galaxy very late in the Sb morphological box, or more appropriately in the Sc box. However, the lack of lumpiness in the disk (seen despite the high inclination angle) precludes the type being as late as Sc which the small bulge size would otherwise suggest. It is very similar to M104, the Sobrero Hat Galaxy, but is 5 times further away.

    This is my last image of the spring - the observatory is now shut down for the summer twilight period. It gives a chance to catch up on maintenance and updates.

    Image Details

    • Dates: 2nd May 2014
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 60D.
    • Exposure: Luminance IDAS-P2 filter 9 x 15 minutes (RCOS) + 13 x 10 minutes RGB CLS filter (Tak)
     

    nuclear ring

    Nuclear Ring in NGC 5905 - copyright Maxxuca et al., 2008. Chart rotated to give north at top as per my image.

    NGC5905/8
    NGC 5908 & 5908

     

    JUNE 8th, 2014

    The Missing Messier M102 - NGC 5866?

     

    This is one the biggest controversies in popular astronomy. One thing is certain, despite what some claim (Sky & Telescope March 2005) the mystery has never been solved. All solutions have to choose to ignore conflicting evidence and just plain errors - depending which you overlook leads to different conclusions.

    What is certain? Well Mechain (the original "discoverer"who forwarded his observation to Messier) described M102 as:-

    102. Nebula between the stars Omicron Bootis and Iota Draconis: it is very faint, near it is a star of 6th magnitude.

    Note: most accept that Omicron Bootis was a mis-reading of Theta Bootis (an easy mistake but one of those errors!)

    The evidence that M102 was a duplicate of M101 emanates from a letter sent by Mechain 2 years later stating M102 was a chart error and saying it was a second observation of M101. Subsequent authors have concentrated on this letter and overlooked the inconsistencies in this solution.

    Messier (after Mechain's report but before Mechain's letter) observed M102 and added a position for it in handwriting on his personal catalogue. There is nothing at his position but the only 2 galaxies bright enough for him to have seen in the vicinity were M101 and NGC 5866. But M101 is about twice as far away from Messier's position as NGC 5866. In addition, remember that nearby 6th magnitude star? The nearest 6th magnitude star to M101 is 2 degrees away whereas NGC 5866 has a 6th magnitude star (actually 6.86) only 30 arcminutes away.

    On balance, there is a reasonable possibility that Messier did observe NGC 5866 thinking he was observing Mechain's M102.

    NGC 5866 belongs to the poor group LGG 396 which includes two main companions, NGC 5907 (Sc) and NGC 5879 (Sbc). NGC 5866 is classed a S0 or lenticular galaxy. Living at the intersection of spirals and ellipticals on the Hubble tuning fork, lenticular galaxies are thought to be remnants of spirals after star formation has ceased or has slowed down substantially.

    Image Details

    • Dates: 26th April 2014
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 60D.
    • Exposure: Luminance IDAS-P2 filter 10 x 15 minutes (RCOS) + 14 x 10 minutes RGB CLS filter (Tak)
     

     

    m102
    NGC 5866 - M102?

     

    MAY 24th, 2014

    Spiral Galaxies NGC 4725 & 4712

     

    The NGC 4725 (centre galaxy) was classed as a Sb/SB(r)II barred spiral by Sandage (1996). Its location has lead to its assignment to the Coma-Sculptor cloud. NGC 4725 (and 4747 out of picture) are relatively isolated dynamically from the remainder of the cloud (e.g., Zaritsky et al. 1997) and comprise what has come to be known as the Coma II Group of galaxies (Tully 1988).

    NGC 4712 (right galaxy) is a background object with a redshift around 4 times that of NGC 4725.

    The original classification for NGC 4725 has been updated to SAB(r)ab pec. This implies a barred spiral with a ring and it is also classed a Seyfert Type 2. The pec(uliar) designation is perhaps due to it having apparently a single spiral arm. In 2008, De Lorenzo-Caceres et al. determined it was a double barred galaxy (see right) and measured the post ion angle of the two bars. The central one is much the shorter and is just visible at the core of the galaxy in my image.

    NGC 4725 was one of the HST Key Project primary calibrators for the infrared Tully-Fisher (IRTF) relationship. Gibson et al. (1998) derived the distance to NGC 4725 from Cepheid variables as part of the Hubble Space Telescope Key Project on the Extragalactic Distance Scale. Twenty Cepheids were discovered, with periods ranging from 12 to 49 days. Using Cepheids in the LMC as a reference, they determined a distance of 41 million light years.

    The distance to NGC 4712 is given as 240 million light years and its classification as SA(s)bc (NED).

    I tried the IDAS-P2 filter for this object in an attempt to reveal the faint outer arm(s) better but I am not convinced that it offers any advantages over the CLS filter which I used on the Tak.

    Image Details

    • Dates: 18th April 2014
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 60D.
    • Exposure: Luminance IDAS-P2 filter 10 x 15 minutes (RCOS) + 14 x 10 minutes RGB CLS filter (Tak)
     

    bars

    Copyright: De Lorenzo-Caceres et al.

    Figure 1 from De Lorenzo-Caceres et al. - "Stellar Kinematics in Double Barred Galaxies: the sigma-hollows" (2008). It shows the position angle of the two bars. The upper-left to lower-right line indicates the axis of the main (visual) bar whilst the other marks the axis of the much smaller inner bar.

    Note: I have rotated the figure to orientate north to the top to match my image.

    ngc4725
    NGC 4725

     

    MAY 11th, 2014

    Dwarf Planet, Makemake

     

    Something moves! This is an animated gif and the movement of Makemake is obvious in the images taken 4 days apart. Look near the centre as the date changes.

    Despite being a bit smaller than Pluto and further away from the Sun, dwarf planet MakeMake is surprisingly easy to track down at (currently) magnitude 16.9. What is even more surprising is that it wasn't discovered until 2005. It must have been recorded on many images prior to that date but was not spotted. My images each night totalled just over an hour but its movement was detectable (just) by blinking the first and last frame.

    Makemake is considered a classical Kuiper belt object, which means its orbit lies far enough beyond Neptune to remain stable over the age of the Solar System. Its discovery in 2005 (along with Eris and Haumea) was the final nail in the coffin for Pluto's status as a planet and lead to the new classification of dwarf planets.

    Strong Moonlight was present on both nights making imaging less than ideal. For a Hubble Space Telescope image click here

    Size: 1,502 km diameter (maximum)
    Satellites: none known
    Orbital Distance (average): 45.79 AU (currently 52.3AU)
    Orbital Inclination: 29°
    Orbital Period: 309.88 Earth years
    Surface Temperature: -240°C
    Discovery Date: 31st March 2005
    Discovered By: Michael E. Brown, Chad Trujillo & David Rabinowitz

    Image Details

    • Dates: 8th & 12th April 2014
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 60D.
    • Exposure: Luminance 4 x 15 minutes (RCOS) both nights + 12 x 5 minutes RGB (Tak)
    orbit  
    makemake
    Makemake

     

    APRIL 27th, 2014

    The Integral Sign Galaxy, UGC3697

     

    The Integral Sign Galaxy and it's 3(?) companions are located in Camelopardalis and together form a "poor" cluster of galaxies known as WBL 132 after White et al., 1999. The integral sign (UGC 3697) and the next largest, the disturbed face on spiral(?) UGC 3714, have very similar redshifts so are almost certainly interacting causing the odd appearance of both and the pronounced integral shape of UCG 3697 in particular. The membership of the group for the other two smaller galaxies is somewhat doubtful as neither have measured redshifts. The tiny edge-on galaxy looks very much like a background object.

    Attention was first called to this object by Burbidge in 1962 and the de Vaucouleurs published a note on its size and distance in 1968. However, a more definitive study was published in 1972 by Richer, Sharpless (of the nebula fame) and Olson in "On the Integral-Sign Galaxy, MCG 12-7-28". On the basis of the distribution of HII regions they concluded that the Integral Sign Galaxy was a peculiar galaxy and not an ordinary barred spiral galaxy seen almost edge-on. Today it is classified as a Sd Pec type - sort of hedging your bets.

    A very windy night so I chose an object at high declination thinking this would stop the telescope blowing about but it didn't.

    Image Details

    • Dates: 19th March 2014
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 60D.
    • Exposure: Luminance CLS filter 8 x 15 minutes (RCOS) + 13 x 10 minutes RGB CLS filter (Tak)
       
    integral
    Integral Sign Galaxy

     

    APRIL 13th, 2014

    The Eskimo Nebula
    Planetary Nebula NGC 2392

     

     

    NGC 2392 was discovered by William Herschel in 1787 from Slough, UK. He thought the nebula surrounding the central star was its “atmosphere”. He didn't coin the name Eskimo - that is probably derived from its appearance in early Palomar pictures. Lord Rosse (and his assistant Storey) also observed it with the 6 foot telescope but could not “resolve it”. We now know it is a planetary Nebula (PN) with a prominent inner ring (the face) and a more diffuse outer halo (the hood). However, the circular morphology conceals much underlying complexity with bars, wisps and knots. It is also known as the Clownface Nebula or Caldwell 39 and is about the same size as Jupiter. It is in the constellation of Gemini.

    It would appear the Ant Nebula Mz3 and the Eskimo Nebula have a lot in common. Despite their totally different appearances, these planetary nebulae are really very similar objects just viewed from different directions. In the case of the Ant Nebula we see it sideways on whilst, in the case of the Eskimo Nebula, we see it pole end on. This perhaps surprising finding was discovered by Y Zhang et al. and published in the Astrophysical Journal in 2012 (see image on right).

    What is poorly known about it (and most planetary nebulae) is its distance. Estimates vary wildly between 2,000 and 7,500 light years. Probably a good compromise would be 4,000 light years.

    I had imaged this object in 2010 but was not happy with the result so returned again to it this year. I just got enough time between clouds for 12 x 15 minutes exposures with an h-alpha filter and as tracking was on form that night I got a much better image. I used the old images, Ha, OIII and CLS (luminance) to fill in the missing information, i.e. colour and the starfield.

    Image Details

    • Date: 7th March 2014 (luminance)
    • Telescope: RCOS 12.5 inch at f/9
    • Camera: Apogee Alta U9
    • Exposure: 12 x 15 minutes with H-alpha filter + RGB from 2010.
      eskimo Zhang
    Eskimo
    Eskimo Nebula

     

    APRIL 1st,, 2014

    Simeis 147

    I have been trying for several years to get an image of this very large and very faint supernova remnant in Taurus. Believed to be around 40,000 years old i.e. the supernova that created it exploded that long ago. All that is left today is this faint filamentary structure and the rapidly spinning pulsar PSR J0538+2817.

    My new (secondhand) 200mm lens was perfect for this object. Although my exposures totalled over 8 hours the weather conditions were very hazy making for low contrast. Hopefully, there will be better conditions next winter. I suspect that a narrowerband h-alpha filter will be required for the best results. I have a year to save up.

    The small nebula to the left (east) is Sharpless Sh2-242.

    Image details:

  • Date: 20th, 27th, 28th February & 3rd March 2014
  • Telescope: Canon 200mm lens at f/2.8
  • Camera: Canon 60D
  • Exposure: 34 x10 mins H-alpha & 15 x 10 mins with UHC filter.
  • Sim147

    Simeis 147


     

    MARCH 16th, 2014

    Asterism Greg's 3

    Discovered (is that the right word?) in Spring 2013 by Professor Greg Parker. His quote: "I found this initially just by scrolling through "the Sky 6" looking to see if there was anything new and interesting to image. I couldn't believe it when a clear "3" flashed across the monitor."

    Because I cannot shoot west, I had to wait 10 months for it come into view for me but, sure enough, a very obvious "3" emerged. It just shows that there are probably more asterisms out there waiting to be spotted.

    RA: 09h 38.0’ DEC: 15˚ 17’ Constellation: LEO Size: 16' x 12'

    Image details:

  • Date: 4th March 2014
  • Telescope: Takahashi FSQ106N
  • Camera: Canon 60D
  • Exposure: 16 x 5 mins with UHC filter.
  • Greg's 3

    Greg's 3


     

    MARCH 2nd, 2014

    The Praesepe or Beehive Cluster

    I know I am always going on about the Lancashire weather but even by our standards this has been probably the worst winter ever with non-stop cloudy/wet weather. For this effort I managed a clear spell from 22:00 pm to 23:38 before the clouds returned again.

    This was one of my first shots with a Canon 200mm f/2.8L lens acquired on ebay. This lens has an excellent reputation for astronomy with several users claiming it works well wide open i.e. at f/2.8. I was very sceptical and used a UHC filter which hugely restricts the spectrum that needs to be focused. My thoughts are that it will focus blue and red very well but not at the same time. I will use f/4 for the next try.

    Image details:

  • Date: 25th February 2014
  • Telescope: Canon 200mm lens at f/2.8
  • Camera: Canon 60D
  • Exposure: 9 x 10 mins with UHC filter.
  • Pleiades

    Praesepe (M44)


     

    FEBRUARY 16th, 2014

    Galaxy M82 & Supernova SN2014

     

    There hasn't been a decent clear night in 2014 but I wanted to grab an image of this supermova. All I could manage was one 5 minute exposure between clouds and then the full Moon was present! Still this starburst galaxy is relatively bright so short exposures can still get an image.

    Sn2014J was discovered in the UK. On the night of January 21, 2014, a group of astronomy students at University College London were scheduled to learn how to use the university's Celestron C14. However, when clouds started rolling in their lecturer, Dr. Steve Fossey, decided to scrub the formal introduction and simply show the students how a CCD camera is used to take an image. The students chose M82 and 10 minutes later the students had discovered the new supernova. It peaked around magnitude 10.5 a few day after and in my image I estimate that it now mag 11.0 or thereabouts.

    Image Details

    • Dates: 13th February 2014
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 40D.
    • Exposure: 1 x 5 minutes
       
    M82-SN2014
    M82 & Supernova SN2014J

     

    FEBRUARY 2nd, 2014

    The Death Star from Star Wars?

     

    Actually the death of a star not the Death Star from Star Wars but it does look a bit like it. In real life it is the Planetary Nebula, Abell 6.

    Located in Cassiopeia this ghostly planetary nebula has virtually no published research data for it. Judging by its symmetrical bubble shape then the central star is probably not in a binary system - stars in binary systems tend to produce more complicated and exotic nebula shapes. What is more definite is that it is around 2 arc-minutes in diameter , has a central star of magnitude 18.3 (B) and is very very faint.

    The usual weather problems meant 4 nights were needed for 4 hours worth of exposures.

    Image Details

    • Dates: 9th, 11th, 17th & 19th December 2013
    • Telescope: RCOS 12.5 inch at f/9 & Takahashi FSQ106.
    • Camera: Apogee Alta U9 & Canon 40D.
    • Exposure: Luminance 13 x 20 minutes (RCOS) + 22 x 10 minutes RGB (Tak)
       
    Abell6
    Abell 6

     

    JANUARY 21st, 2014

    Jupiter & Io

     

    It was that time of year to dust off the old Celestar C8 and dig out the webcam for their annual planetary imaging turn. This year I had an electric focuser and a flip mirror. They don't half make life easier. Taken from Frettenham, Norfolk whilst grandsons sitting.

    Image Details

    • Dates: 17th January 2014 from Frettenham, Norfolk
    • Telescope: Celestron Celestar 8-inch SCT @ f/20
    • Camera: Microsoft Lifecam Webcam
    • Exposure: Best from 3000 frames at 20 fps.
       
    Jupiter
    Jupiter & Io

     

    JANUARY 12th, 2014

    The Pleiades or Seven Sisters

    Not the best of nights with strong winds so continued trying out my Canon 60D on the 300mm focal length Pentax lens. There's a lot of faint material around this cluster and that was the reason for 5 hours worth of exposures - overkill for just the Pleiades. Tried 10 minutes and 15 minute sub-exposures with the shorter being better as the IDAS filter is not the best at blocking light pollution. It does however, pass the blue colours reasonably well

    Latest thinking on the Pleiades seems to suggest that the nebula is not associated with the cluster - it just happens that the cluster is passing through the nebula at this particular time. The distance to the cluster is highly debated and disputed but 400 light years is probably reasonably close. Its age is around 115 million years - older than it used to be thought.

    Image details:

  • Date: 22nd & 30th December 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 60D
  • Exposure: 5 hours with IDAS-P1 filter.
  • Pleiades

    Pleiades


     

    JANUARY 5th, 2014

    The Double Cluster

    A bit out of order but just a quick 1 hour exposure to test out my new (secondhand) Canon 60D. The results look encouraging - the fixed pattern (banding) noise seems much reduced on this model and the articulated screen means it's easy to see even after a meridian reversal. Sure the pixels are a bit small so probably snsitivity will take a knock but I am hoping it is more steps forward than backwards. Used IRIS for processing and the 18 mega-pixel images were no struggle at all.

    The cluster on the left (east) edge is NGC 957.

    Image details:

  • Date: 30th December 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 60D
  • Exposure: 12 x 5 mins with IDAS-P1 filter.
  • Double Cluster

    The Double Cluster


    To continue with the imageBLOG for 2013 Click Here

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