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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 renta-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 the Canon has 5 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!

NEW AstroCanvas NEW - Prints on canvas of my latest images now available. Note if there is one you would like that is not listed there (yet) please email me.

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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 cae 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 lighty 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 emough 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: Takahashis 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


     

    DECEMBER 29th, 2013

    Galaxy NGC 7610 & Supernova SN2013fs

     

    Located just below the Square of Pegasus, this rather faint Scd type spiral galaxy is around 150 million light years distant. It was discovered by Andrew Ainslie Common. However, due to an error on his part this galaxy has 2 NGC numbers 7610 and 7616. The latter is almost certainly a second observation of 7610 and there is nothing at the coordinates he gave for 7616.

    Common discovered 30 NGC objects visually with his 36" f/5.9 reflector at Ealing, UK. Common's objects, which are all galaxies, were published in New Nebulae, (1882). The telescope mirror was made by George Calver and the telescope was erected in 1879, replacing the 18" reflector built in 1876. The "3 foot" as it was known, had a truss tube on a fork mount in a wooden observatory. In 1885, it was sold to Edward Crossley who built a new "iron" observatory for it at Bermerside House, Halifax, Yorkshire. Frustrated by the usual northern weather, he offered the observatory and telescope to the new Lick Observatory (Mt. Hamilton, USA). It was moved in 1893 and became operational in 1895 when it became known as the "Crossley Reflector".

    Supernova SN2013fs was discovered by Koichi Itagaki (Japan) on 6th October 2013. This is a Type IIP (was IIn) (z=0.012). I would estimate it was around magnitude 16 to 17 on my image - using the raw image as the image here is non-linearly stretched.

    Image Details

    • Dates: 29th November 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9 & Canon 40D.
    • Exposure: Luminance 10 x 10 minutes with IDAS filter (RCOS) + 10 x 10 minutes RGB Takahashi FSQ106
       
    NGC7610
    NGC 7610

     

    DECEMBER 22nd, 2013

    Andromeda Galaxy Globular Clusters G1 & G2

     

    G1 is the most luminous globular cluster in the Local Group and probably the most massive at 4 to 7 million M⊙ (Barmby et al. 2007; Ma et al. 2009). It is noticeably elliptical but this is common for the largest globular clusters. A comparison with a variety of simple stellar population (SSP) models yields a mean age which is consistent with G1 being among the oldest building blocks of M31 and having formed within ~1.7 billion years after the Big Bang (Ma et al., 2009).

    Ma et al also found that G1 has similar properties to ω Centauri, M54 and NGC 2419 - large globular clusters belonging to our galaxy. All three of these objects have been claimed to be the stripped cores of now defunct dwarf galaxies so is G1 perhaps the core of a stripped dwarf galaxy? Ma et al. considered this in detail whether GCs, nucleated dSph cores and normal dwarf galaxies form a continuous type or if GCs and dSphs constitute distinct classes of objects. They presented arguments in favour of this latter option ie they are separate objects. The jury is probably still out though!

    Kong et al., 2010 investigated the premise that G1 has a black hole at its centre. Based on Keck and Hubble Space Telescope (HST) observations, it has been claimed that G1 hosts a ∼ 2 × 104 M⊙ object at the core (Gebhardt, Rich & Ho 2002, 2005) - in other words an intermediate size black hole (IMBH). However, the suggestion of an IMBH is controversial and has been challenged by Baumgardt et al. (2003). Recently, X-ray emission near the core of G1 has been discovered based on XMM–Newton observations (Trudolyubov & Priedhorsky 2004; Pooley & Rappaport 2006; Kong 2007) and it is suggested that the X-rays come from Bondi accretion from cluster gas on to a central IMBH. Kong et al seemed to conclude that it is not proven that G1 does have a black hole at its centre.

    Globular Cluster G2 = Mayal III and magnitude 15.8V.

    Galaxy North-East of G2 is UGC330 (PGC2026). It is of type S0 at a distance of around 260 mly - obviously a background object.

    Image Details

    • Dates: 24th November 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9 & Canon 40D.
    • Exposure: Luminance 2 hours with IDAS filter (RCOS) + 2 hours RGB Takahashi FSQ106

    HST-G1

    Hubble Image: Ma et al., 2007. Note their N and E directions are both in error. North is 45 degrees out and East is 135 degrees out. That's professionals for you!

    G1 and G2
    Globular Clusters G1 & G2

     

    DECEMBER 15th, 2013

    Emission Nebulae Sharpless Sh2-168 & Sh2-169

     

    Close to Beta Cassiopeia, this pair of emission nebulae are rather ignored with few images and data available. Only Avedisova's " A Catalog of Star-Forming Regions in the Galaxy (2002)" has some information. Sh2-168 is the brighter and Sh2-169 very faint.

    Sh2-168: Avedisova catalogues Sh 2-168 as being ionised by the O9 V star LS I +60 50. Avedisova locates Sh 2-168 in the star formation region SFR 115.80-1.60 along with the radio source KR 84 and in the general direction of the expanding shell surrounding Cassiopeia association OB5. The nebula includes the loose infrared cluster [BDS2003] 47 and the Herbig-Haro object GM 2-44.

    Sh2-169: A very faint nebulosity just south-east of Sh2-168. Avedisova catalogues it as being ionised by the B0 III giant BD +59 2786. The Sharpless Catalogue places this nebula in the "faintest" category.

     

    Image Details

    • Dates: 22nd & 23rd November 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9 & Canon 40D.
    • Exposure: Luminance 4.67 hours with H-alpha filter (RCOS) + 3 hours RGB Takahashi FSQ106
       
    sh2-168
    Sharpless Sh2-168 & 169

     

    DECEMBER 8th, 2013

    The Eye of the Dragon (Sh2-190, IC 1805)

     

    The Dragon's Head is just part of the large emission nebula popularly called the Heart Nebula. Often referred to erroneously as IC 1805 but the latter is actually just the open star cluster at the centre of the Nebula (see right). The nebula is more accurately described as Sharpless Sh2-190. This in turn is part of the even larger Cas OB6 association and a giant "superbubble" is being blown northwards and out of galactic plane from this region. Radio sources within the nebula, associated with intense star formation (known as W3 & W4), have enabled the distance to the nebula to be determined as 6500 light years.

    With very strong moonlight (93% full) targets were somewhat limited so I settled on an object that I had imaged before but this time I wanted it to take centre stage.

    Image Details

    • Dates: 14th November 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9 & Canon 40D.
    • Exposure: Luminance 4 hours with H-alpha filter (RCOS) + 4 hours RGB Takahashi FSQ106
    Location of the Dragon's Head
    in the Heart Nebula
    Dragon finder
    Dragon'sHead
    The Dragon's Head in IC1805

     

    DECEMBER 1st, 2013

    Interacting Galaxies NGC 7753/7752 (Arp 86)

    The NGC7753 and NGC 7752 system was catalogued by Arp in his Atlas of Peculiar Galaxies as Arp 86. It bears a striking resemblance to M51 but being around 9 times further away is much smaller and fainter. It comprises 2 interacting galaxies consisting of a grand-design barred spiral galaxy (NGC 7753) and a small companion (NGC 7752) joined by a "bridge" formed from a spiral arm. Systems like this are surprisingly common. Why? To answer this question, Salo and Laurikainen (1993) first took deep CCD images of the system and then attempted to model it using N-body computer simulations. Their findings produced some interesting and surprising results.

     

    Properties of the System

      NGC 7753 NGC 7752
    Major diameter 3.3′ 0.8′
    Minor diameter 2.1′ 0.5′
    Classification SAB(rs)bc I0
    Radial velocity 5160 km s−1 4940 km s−1
    Distance 68 Mpc (220Mly) 68 Mpc (220Mly)

     

    The following is based largely on Salo & Laurikainen's 1993 research paper:-

    1. The components of Arp 86 are presently moving in a low-eccentricity low-inclination orbit with a period of 800 - 900 million years. The system is not the result of a first or single passage.

    2. The likelihood is therefore that the several M51-type spirals might represent the same kind of system with bound orbits, rather than non bound single passages observed at precisely the correct time. This is supported by the fact that the system shows M51-type structure over several revolutions. So M51 type systems are not the result of observing a single event at a highly fortuitous time but the odds are more favourable in that these are recurring events repeating each orbit.

    3. Most surprisingly the principal perturbation event occurred about 600 Myr ago as the companion passed below the plane of the main galactic disk. That is, the "bridge" in the vicinity of the companion is originally due to perturbation occurring when it was at the opposite side of the main galaxy i.e. when the companion was passing downwards through the NGC 7753 plane. The most recent upward crossing occurred about 50 Myr ago and has resulted in NGC 7752 coincidently appearing at the end of the "bridge" formed 600 million years earlier. Quite an unexpected finding.

    4. About 5% of the main galaxy gas mass can be transferred to the companion during the interaction. This mass flow causes the observed starburst. Captured gas as well as the original gas of the companion becomes trapped in the inner ring structures. The clumpy structure obtained in the simulation is in agreement with observations. The simulation has even reproduced the bifurcation observed in the real bridge.

    Conclusion

    So M51 type systems are the result of viewing a system at a slightly fortuitous time but not that fortuitous because they they can occur repeatedly over several orbits.

    Also visible in my image is the fading supernova SN 2013Q


    Image Details:

    Weather was very poor during November and to get 3 hours worth of exposures took shooting between clouds on 3 nights. The light pollution filter I used was an IDAS as this filter, with its blue bandbass, is probably the best for galaxies.

     

    • Dates: 4th, 7th & 10th November 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with IDAS filter (RCOS) + 2 hours RGB Takahashi FSQ106/Canon40D
     

    Sato Laurikainen

    Computer model of the Arp 86. The path of the smaller galaxy is shown solid where it is above the plane of NGC 7753 and dashed where it is below the plane. Note the simulation mimics the bifurcation of the joining spiral arm. Pretty impressive!

     

     

    SN2013Q

    Supernova SN2013Q

    NGC 7753

    NGC 7753


    NOVEMBER 17th, 2013

    The Other Ring Nebula, Abell 80

    Located in Lacerta this seldom imaged planetary nebula bears a striking resemblance to M57.

    Very little published information for this object. Appears to about 3000 light years distant. The central star is listed as magnitude 19.6 so the illuminating star is not the brightest one in the centre - it's not the right colour so I already I had my suspicions - they are normally very blue. I assume it must be the one above and left a bit of the brightest central star?

    Image details:

    • Date: 9th & 15th October 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with H-alpha filter (RCOS) plus RGB 3 hours with Takahashi FSQ106/Canon 40D

     

    Abell80

    Abell 80


    NOVEMBER 3rd, 2013

    Reflection Nebula NGC 7129 in Cepheus

     

    Calling it a reflection nebula doesn't do NGC 7129 justice - it much more complex than that. Hartigan & Lada brought most of what was known about this object, along with their own data, all together in one paper in 1985. The chart (right) is what they compiled

    Hartigan & Lada were primarily looking for Herbig Haro objects. Herbig–Haro objects (HH) are small patches of nebulosity associated with newly born stars and are formed when high-speed jets of gas ejected by young stars collide with clouds of gas and dust nearby. They are common in star-forming regions and several are often seen around a single star, aligned with its rotational axis. HH objects are transient phenomena, lasting not more than a few thousand years.

    NGC 7129 includes no less than 5 HH objects - small odd red shapes in the image. HH105 is the faintest but the other 4 much more obvious (all marked with + signs).

    Objects catalogued by Hartigan & Lada (1985) - listed North to South :-

    • V350Cep - T Tauri star (appears to be brightening)
    • GGN33a - reflection nebula
    • GGN33b - reflection nebula
    • GGD34 - HH Object
    • GGD35 - HH Object
    • HH105 - HH Object
    • LkHa234 - Ha emission star (age approx. 200,000years)
    • BD+65º1637 - Ha emission star
    • BD+65º1638 - bright star
    • SV6 - Stro-Vrba-Strom No6, near infra-red star (possible Ha emission star)
    • RNO138 Red Nebulous Object (possibly illuminated by SVS6 or FIRS)
    • GGD32 - HH object
    • FIRS - Far Infra-red Source (approx 1000x luminosity of the Sun)
    • HH103 - HH object
    • unlabelled unfilled circles (3 no.) - water masers
    • contours - CO gas

    Image Details:

    Very difficult object to image from a light polluted site. For the first time I tried shooting the luminance with an IDAS LPS filter - this light pollution filter has an additional pass band well into the blue end of the spectrum. In addition I shot an H-alpha image just to make sure the small red structures (HH objects) referred to above were recorded. I also shot RGB with the Tak just to cover all the bases. I was pleased with the result even though I could never match the dark sky boys.

    • Dates: 22nd, 27th, 28th & 30th September 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 4 hours with IDAS-P2 filter and 2 hours H-alpha (RCOS) + 3 hours RGB Takahashi FSQ106/Canon40D

    HH objects

    Finder chart for locating the various objects in the NGC 7129 complex.
    Chart copyright Hartigan & Lada, 1985 (background aligned image is mine).

    NGC7129

    NGC 7129


    OCTOBER 20th, 2013

    The Milky Way at the Kelling Heath Star Party

    I have attended the Autumn Star Party at Kelling Heath, Norfolk for the last 10 years now and every year I am amazed at the spectacle of the Milky Way - we just cannot see it properly (if at all) in Lancashire. With those huge Norfolk skies it dominates the night sky.

    To try and fit in as much as possible I used a Sigma 10-20mm zoom set at 10mm. Zoom lenses are not ideal but it was the widest angle I could lay my hands on. These lenses have a huge front element and with it pointing straight up my dew heater was not up to the job - hence only 4 exposures.

    However, what was disappointing was the worsening light pollution evident in the raw stack (right). The glow on the left is Sheringham, the glow on the right Holt and there's a bit on the bottom edge from Norwich. So next time I will use a light pollution filter and stop the lens down to f/8 - that's progress!

    Image details:

    • Date: 5th October 2013
    • Telescope: Bolton Tracker
    • Camera: Canon 20Da + 10mm lens at f/5.6
    • Exposure: 4 x 5 mins

    Moorsel Chart

    Raw stack showing the Kelling Heath light pollution

    NGC691

    The Milky Way over Kelling Heath


    OCTOBER 13th, 2013

    Emission Nebula Sharpless Sh2-112 (Detailed view)

    My first image of the autumn with the 12.5 inch RCOS - focused with the Bahtinov mask - see below. The previous widefield image provided the RGB colour for this image. The images were shot simultaneously, which maximises the few clear nights we have. I was going to caption this one as a "close-up" but of course it is no closer just more detailed.

    For description of the object - see the widefield shot below.

    Image details:

    • Date: 14th September 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with H-alpha filter (RCOS) plus RGB 3 hours with Takahashi FSQ106/Canon 40D

     

    Sharpless Sh2-112

    Sharpless Sh2-112


    SEPTEMBER 29, 2013

    Turn Right at Deneb: Emission Nebula Sh2-112 (Widefield)

    This wide-field image was taken to provide the colour for a detailed H-alpha image taken with the RCOS. However, the surrounding area turned out to far from empty and virtually covered in faint nebula plus several dark nebulae so I decided it was well worth processing in its own right.

    Sh2-112 refers to just the central bright nebula located just over 1 degree west of Deneb in Cygnus. It is an HII emission region of apparent size of about 15 ' crossed by a prominent dark band. It is believed that the star responsible for ionising the nebula is not Deneb but the blue double star (class O8V) near its center. It has an apparent magnitude of 9.6 and is known as BD +45 3216 or WDS A740. Estimates for the distance of this star provide a value of about 5670 light years, which would place Sh2-112 in the region of the Orion Arm. Ref: Wiki

    • Date: 14th September 2013
    • Telescope: Takahashi FSQ-106 (4-inch Refractor)
    • Camera: Canon 40D.
    • Exposures: 18 x 10 mins with UHC filter.
    Sh2-112

    Sh2-112


    SEPTEMBER 22nd, 2013

    Bahtinov Mask on the RCOS

     

    I have always used visual focusing for the RCOS (12.5 inch R-C Telescope) based on the sharpness of the diffraction spikes and the length of the bloom (bleeding) on a magnitude 1 star. However, with an H-alpha filter in place this meant exposures of 30 seconds or so as this filter really reduces star brightness. I decided over the summer to try a Bahtinov mask and a bespoke one was ordered from StarSharp (Morris Engraving). The first one received was undersize but this was replaced by a correctly sized one without hassle. It was time to try it out.

    The RCOS has a secondary focuser that moves in steps of 1/40,000 inch. With the old method I would focus in steps of 10 units ~ (1/4,000 inch) and could usually get focus to plus or minus this amount. So what does the Bahtinov mask produce? The two images are what I got with 5 second exposures on Deneb. So 6 times faster than my 30 second exposures to start with. Hopefully you can see the subtle difference 10 units has made - the left is a focus count of 35 and the right image a count of 25. The right one is obviously the correct position as the centre-line of dots bisect the cross of the outer lines of dots.

    A secondary movement of 1/4000th inch equates to a 1/1422th inch shift for the focal plane. So the Bahtinov mask can focus the RCOS to better than 1/1000th inch and requires much shorter exposures when using a narrowband filter. I shall be using it exclusively from now on.

    Image details:

    • Date: 14th September 2013
    • Telescope: RCOS at F/9
    • Camera: Apogee Alta U9 - 1x1 bin
    • Exposure: 5 secs with H-alpha filter
    Focus


    SEPTEMBER 15th, 2013

    The Brown Brown Dust of Home
    Cocoon Nebula (IC5146), Dark Nebula B168 & Open Cluster NGC7209

    Its difficult to image the dust clouds of the Milky Way from my location. The obligatory light pollution filters knock out most of the brown hues but I have this time been able to recover at least some of them. It was tight to fit in all 3 objects at the same time and the open cluster NGC7209 has ended up right on the left hand edge.

    The NGC description for IC5146 refers to an irregular cluster of 9.5 mag stars involved in bright and dark nebula - so it includes both the cluster and nebula. The nebula itself is also known as Sh2-125. The Cocoon nebula is both a reflection and emission type with its own dust lanes and is located at the end of the dark streamer B168 - 3 nebulae for the price of one!

    The complex is classed as a molecular cloud with a young star cluster embedded within it. The cluster is dominated by the central star BD+463474, a B0V type, which excites the symmetrical H-II nebula (Sharpless 125). In the model proposed by Roger & Irwin (1982), the Cocoon’s ionised gas (H-II) has broken through the surrounding dark cloud (B168) while the bulk of nebular remains behind BD+463474, obscuring background stars. H-alpha emission-line stars were discovered in the Cocoon by Herbig (1960). Forte et al. (1984) estimated the stellar population to be around 110 stars most of them were probably contracting objects with an age 1 to 3 million years and spectral class K. However, Lada et al. (1999) using infrared images were able to penetrate much deeper into the nebula and were able to find five times as many heavily obscured proto-stars - ref: Observing the Caldwell Objects - David Ratledge, 2000.

    Image details:

  • Date: 7th September 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 40D
  • Exposure: 40 x 5 mins with UHC filter.
  • Cocoon Nebula

    Cocoon Nebula


    SEPTEMBER 8th, 2013

    North American (NGC7000) and Pelican Nebulae (IC5070)

    A poor run of cloudy weather meant choosing a brightish object to image between clouds.

    The North America Nebula (left) and the Pelican Nebula (right) are in fact parts of the same interstellar cloud of ionised hydrogen (H II region). They are divided by a dense dark molecular cloud L935. The puzzle has been to find the star responsible for ionising the nebula. It is certainly not the nearby Deneb and various other candidates have been suggested. However, the issue was resolved in 2004/5 by Comeron & Pasquali when they found behind the dark nebula, near the very centre of the H II region, a heavily obscured O type star with matching spectral type. The star they identified has a mass of 60x the Sun. The nebula was discovered by William Herschel on 24th October 1786 from Slough, England.

    Image details:

  • Date: 26th August, 3rd & 4th September 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 40D
  • Exposure: 32 x 5 mins with UHC filter.
  • North American Nebula

    North American and Pelican Nebulae


    SEPTEMBER 1st, 2013

    Wild Duck Cluster, M11

    My first image of the autumn and as it was a poor hazy night I settled on a relatively easy object.

    The cluster's popular name was coined by Admiral WH Smyth who, in the 19th century, thought it resembled "a flight of wild ducks". The description occurs in what became known as the Bedford Catalogue (his observatory was in Bedford). The Bedford Catalogue comprised his observations during the 1830's of about 1000 deep-sky objects and was published in 1844 becoming one of the earliest deep-sky catalogues. He located the Wild Duck Cluster in the defunct constellation Actinous whereas today it is in Scutum. It was his entry number 664 so it could be called B664.

    This open cluster would be visually one the best in the sky if it were not so low down for us in northern England. It is one of the richest and most compact of the open clusters perhaps containing up to 3000 stars. It's age is around 220 million years. Several dark nebula surround M11.

    • Date: 25th August 2013
    • Telescope: Takahashi FSQ-106 (4-inch Refractor)
    • Camera: Canon 40D.
    • Exposures: 19 x 5 mins with UHC filter.
    wild Duck

    M11


    AUGUST 15th, 2013

    Milky Way through Scutum & Serpens

    It's taken 4 years for me to find a way to remove the light pollution from this shot. I eventually did it by removing it from each frame individually (using a mask) before finally stacking. Trying it after stacking just didn't work. The moral - never give up!

    The prominent blue cluster 3 quarters across and about 1/5th down (near Beta Ophiuchi) is IC4665. The lowest Nebula visible is M8, the Lagoon Nebula. Altair is near the top at the left (east).

    • Date: September 2009
    • Telescope: Bolton Tracker
    • Camera: Canon 20Da + 20mm Pentax lens @ f8
    • Exposure: 9 x 5 minutes
    Gemini

    Scutum-Serpens


    JULY 14th, 2013

    Zwicky's Necklace, 8 Zw 388

    My last image of spring 2013 and one that I struggled with due to poor seeing so I couldn't really get enough signal to do it justice. There are one or two published images around but I wanted a colour one. Thanks are due to Wolfgang Steinicke for drawing attention to this object in his book "Galaxien" published by Oculum-Verlag (2012) ISBN 978-3-938469-56-9. This book is highly recommended even though it is in German and despite getting my name wrong!

    Zwicky's Necklace is number 288 in Zwicky's 8th Catalogue of Compact Galaxies. Zwicky was a colourful character and is credited with first deducing the presence of dark matter way back in 1933. The anecdote that amuses me most about him is his opinion of colleague astronomers whom he referred to as "spherical bastards" - whichever way he looked at them they were still bastards!

    Despite this object being known for over 40 years virtually no data is available for it. It comprises 10 to 12 galaxies arranged in an usual shape with magnitudes from 18 and fainter. Its distance is unknown but on the basis of its brightness it must be of the order of 1 billion light years distant - my guess!

    Image details:

    • Dates: 2nd, 7th and 13th May 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with CLS filter (RCOS) plus RGB 3 hours with Takahashi FSQ106/Canon 40D

     

    Zwick's Necklace

    Zwicky's Necklace


    JUNE 28th, 2013

    Ultra Compact Dwarf, SUCD1

     

    Background

    Ultra-compact dwarf galaxies (UCD) are a recent discovery and are very compact objects with very high stellar population counts. They are currently one of the hottest topics in professional research. They are thought to be in the order of 200 light years across yet with up to a hundred million stars. UCDs were discovered initially in the Fornax Cluster by Hilker (1999) and Drinkwater (2000) but have subsequently been found in other clusters including the Virgo Cluster.

    It was originally theorized that these are the cores of dwarf elliptical galaxies that have been stripped of gas and outlying stars by tidal interactions during their path through the hearts of rich clusters. However, evidence began to emerge that these objects shared many similarities to globular clusters - only that they were much bigger and brighter. The debate still rumbles on but the mega-globular cluster interpretation seems to winning the argument. So they are are probably not galaxies but the biggest of all star clusters- plus note their acronym does not include the word galaxy!

    SUCD1

    It was probably the discovery of an UCD associated with M104 by Hau et al. (2009) that started to tip the balance in favour of the mega star cluster scenario. The HST image they used is shown inset in mine. This was by far the nearest UCD known and so could be studied in much more detail - they named it SUCD1. They found a size of around 100 light years and mass of around 33 million Suns. Their results also showed no need for a dark matter presence which is normal for star clusters but not for dwarf galaxies, which tend to be dark matter dominated. Their detail findings supported the massive globular cluster model.

     

    Image details:

    • Dates: 29th April & 1st May 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with CLS filter (RCOS) plus RGB 3 hours with Takahashi FSQ106/Canon 40D
    SUCD1


    JUNE 23rd, 2013

    Sombrero Galaxy, M104

    Really this object is far too low for imaging from Lancashire but it is such an interesting galaxy I just had to have a go. Because its centre is so bright and normally over-exposed, I used a combination of 5 minute and 15 minute exposures to achieve the necessary high dynamic range.

    Despite being obviously a spiral galaxy with a very prominent dust lane tilted just 6 degrees from exactly edge-on, M104 does share some features with elliptical galaxies. Namely it has a huge central halo, an active galactic nucleus with a supermassive black hole of around 1 billion solar masses and a large retinue of globular clusters (2000). It is classed as LINER (low ionization nuclear emission region) galaxy. Its distance is around 30 million light years and seems to located somewhat on its own rather than part of a group. All in all - a very untypical spiral galaxy and the presence of an UCD see above) only added to its uniqueness.

    Image details:

    • Dates: 29th April & 1st May 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with CLS filter (RCOS) plus RGB 3 hours with Takahashi FSQ106/Canon 40D

     

    M104

    Sombrero Galaxy, M104


     

    JUNE 8th, 2013

    The Jet from M87 (Virgo A)

    Observations of M87’s jet go back to 1918 (Heber Curtis, Lick). Over the years there have been many suggestions as to its source. Halton Arp even suggested it aligned with M84 and M86 which he postulated had been ejected from M87. However, today we know that the jet is powered by a rapidly spinning accretion disk around M87’s supermassive black hole. This black hole is currently thought to be around 6.3 solar masses and is the third largest known.

    Recent research by Doeleman et al. (October 2012) explains it well “Approximately 10% of active galactic nuclei exhibit relativistic jets, which are powered by accretion of matter onto super massive black holes.” They also detected the jets “launch point” as at “5.5 +/- 0.4 Schwarzschild radii (which) is significantly smaller than the innermost edge of a retrograde accretion disk, suggesting that the M87 jet is powered by an accretion disk in a prograde orbit around a spinning black hole.”

    Hubble measured the speed of the jet and found that it exhibited superluminal velocity - around 4 to 5 times that of the speed of light. This is a line of sight effect due to the jet approaching us at close to the speed of light. So the jet doesn’t after all point towards M84 and M86 - it's more towards us than sideways. There will be a counter-jet but as it is travelling substantially away from us it is virtually invisible.

    The jet is easily revealed by subtracting a model of a smooth elliptical galaxy from the real one. I used a blurred image for this. This technique also reveals many faint fuzzies around M87 which are some of its globular clusters.

    Image details:

    • Dates: 19th April 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with CLS filter (RCOS) plus RGB 3 hours with Takahashi FSQ106/Canon 40D

     

    M87

    M87's Jet


     

    JUNE 2nd, 2013

    A Trillion Suns - otherwise known as M87 (Virgo A)

    This featureless looking elliptical galaxy is in fact the dominant and central galaxy of the Virgo Cluster. It is a supergiant in every respect:

    • A total mass 200 times that of the Milky Way i.e. several trillion solar masses;
    • On deep photos (David Malin AAT) it extends to a size greater than the full Moon. This equates to a diameter of 500,000 light years;
    • A central black hole that is one of the biggest known at 6.3 billion solar masses and it devours the equivalent mass of the Sun every 10 years;
    • A superluminal jet from its nucleus shooting out material 5,000 light years:
    • Around 100 times more globular clusters than the Milky Way – approximately 15,000:
    • It is both a radio galaxy (Virgo A) and a powerful x-ray source (Virgo X-1).

    On this image I have concentrated on the galaxy and its neighbours. The next plan is to re- process the raw image so as to reveal the jet.

    Image details:

    • Dates: 19th April 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 3 hours with CLS filter (RCOS) plus RGB 3 hours with Takahashi FSQ106/Canon 40D

     

    M87

    M87


    MAY 26th, 2013

    M85 and NGC 4394

    Note - 3 images are needed for this complex group of objects! Top right is just the central region of M85 with positions of globular clusters shown. Lower right image is a close-up of the Quasar. The main image (bottom) shows M85 and its environs.

     

    Although originally classified as an elliptical galaxy, closer inspection of M85 (centre in bottom image) clearly reveals it to be much more complicated than that. NED classifies it as a SA(s)0+ pec and a recent paper by Bazerla et al (2010) finds evidence for S, E/S and Sa types. Clearly one mixed up galaxy. so perhaps a peculiar lentticular covers it best. It is obviously distorted with faint extended plumes and shells. The cause of this confusion is more likely to be galaxy mergers than interaction with its companion NGC 4394 (left in main image below) as it looks relatively un-disturbed. Strong evidence for M85 undergoing a recent merger is a Hubble image showing that M85 has a double nucleus.

    NED classes NGC 4394 as (R)SB(r)b LINER indicating a barred spiral with an active nucleus - no doubt black hole powered. It has a similar redshift to M85 so although probably not interacting with it must be relatively nearby.

    The third main galaxy (right in bottom image) is IC 3292 and is classified as a dwarf SO type.

    The faint galaxy overlying M85 to the south is MGC +03-32-028. Many other background galaxies cover the field.

    M85 has a large family of Globular Clusters and several are visible in my image as faint "stars" overlying the galaxy. They are located to left of the yellow bars in the enlarged image on the right. It is difficult to assess magnitudes for these as they are all but swamped by the light of the galaxy but they appear to be around magnitude 21.

    M85-GlobCl

     

     

     

     

     

     

     

     

     

    However, perhaps the most interesting object is the Quasar QSO J1225+1813 (SDSS J122517.16+181346.5) appearing through M85 towards its top right edge (labelled QSO in top right image and Q in lower right image).

    At magnitude 19.1 this Quasar has a redshift of 1.19 indicating that the light travel time is of the order of 8.5 billion years. Just to the north of it, but probably unconnected, are a pair of galaxies at magnitudes 20.7 & 21.1. The faint objects at the left are a galaxy at mag 21.6 and, above it, a star at mag 20.1. The star at the top edge is mag 19.1.

     

    Image details:

    • Date: 6th April 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 2.5 hours with CLS filter (RCOS) plus RGB 2.5 hours with Takahashi FSQ106/Canon 40D
    qso
    M84 M86

    M85 and NGC 4394


    MAY 19th, 2013

    Virgo Cluster Mosaic

    The Virgo Cluster comprises up to 2000 member galaxies and forms the heart of the even larger Virgo Supercluster, of which our Local Group is just an outlying member.

    With the Eyes and the M84/M6 mosaic already taken I only needed the bottom left corner to complete a 4 panel mosaic. I was able to shoot the missing piece on the 27th April. It only contained one galaxy of note, the insignificant NGC4425 but it was a poor night so nothing to lose really.

    The Observatory is shut now for the summer - it doesn't get dark properly again here until August. Still a few more images to process though.

    Image details:

    • Dates: 1st, 3rd, 4th, 5th & 27th April 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 9 hours with CLS filter (RCOS) plus RGB 9 hours with Takahashi FSQ106/Canon 40D

     

    M84 M86

    M84 M86


    MAY 12th, 2013

    Galaxies M84 & M86 - Virgo Cluster

    This pair of giant elliptical galaxies are probably not quite as close together as they look. Although both are part of the large Virgo Cluster, M86 (left) is part of its own sub-group (including NGC 4438 - see below). It has a large velocity relative to other members of the main group and is falling towards the centre from the far side. This fall is so fast that is has a blue shift (ie approaching us). M84 (right) is part of the sub-group dominated by M87. A third sub-group surounds M49. Hubble images of the nucleus of M84 have revealed jets powered by a central black hole.

    The edge-on spiral galaxy towrds the top is NGC 4402. It is suffering "ram-pressure stripping" as it falls through the intra-cluster medium. There's a great Hubble image of this galaxy. The edge-on spiral towards the botton is NGC 4388 and is probably suffering a similar fate. It is classed as a Seyfert 2 type galaxy and there is also an excellent image available - this time taken with the 8 metre Subura telescope.

    A two panel mosaic was required to fit these large galaxies and their neighbours all in. Ten minute sub-exposures were used to prevent the galaxy cores over-exposing.

    Image details:

    • Date: 3rd, 4th & 5th April 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: Luminance 4 hours (25 x 10 mins) with CLS filter (RCOS) plus RGB 3 hours (25 x 10 mins) with Takahashi FSQ106/Canon 40D

     

    M84 M86

    M84 M86


    MAY 8th, 2013

    The Eyes, Galaxies NGC 4435 & 4438

    The Eyes is the popular name given to this pair of galaxies close to the centre of the Virgo Galaxy Cluster, 50 million light years distant. NGC 4438 is the larger galaxy and is thought to have been originally a spiral galaxy which has been highly distorted by a close encounter with another galaxy. In contrast, the second smaller galaxy, NGC 4435 is a barred lenticular galaxy which appears remarkably undisturbed. So rather than these two galaxies interacting it is more likely that the giant elliptical galaxy M86 (out of shot) is the culprit in distorting NGC 4438. Recent observations have found filaments of hydrogen gas connecting NGC 4435 to M86, highly suggestive of a collision in the past.

    Image details:

    • Date: 1st April 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: 3 hours (9 x 20 mins) with CLS filter (RCOS) plus 3 hours (18 x 10 mins) RGB with Takahashi FSQ106/Canon 40D

     

    abel1495

    The Eyes


    APRIL 28th, 2013

    Galaxy Cluster Abell 1495

    A bit confusing as Abell produced a catalogue of Galaxy Clusters as well as Planetary Nebulae. This time it's from his "Catalog of rich clusters of galaxies".

    This image is taken from the top-left (north-east) corner of the full frame of my image of the Box (Hickson 61). It serendipitously included Abell 1495 so it always pays to check what else has been captured in an image. Abell counted 123 galaxies from magnitude 17 down to magnitude 19. My image goes a bit deeper - probably around magnitude 21 - and consequently reveals even more, around 200 galaxies, despite not including all of it. Most of the galaxies are, of course, just faint smudges at its huge distance of 1.8 billion light years. The bright star is SAO 82192 and is magnitude 9.44.

    Image details:

    • Date: 30th March 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: 3.33 hours (10 x 20 mins) with CLS filter (RCOS) plus 3.33 hours (20 x 10 mins) RGB with Takahashi FSQ106/Canon 40D

     

    abel1495

    Abell 1495


    APRIL 21st, 2013

    The Box, Hickson Compact Galaxy Group 61

    An intriguing group of 4 galaxies forming an eye-catching rectangle or box - hence the name. However, in reality we are looking at objects at hugely different distances. The colour gives a clue in that the blueish galaxy (61b) is the odd one out. It is relatively nearby at around 25 million light years. The other 3 could form a background trio at 180 million years but distance estimates for 61c place it nearer at 140 million light years. Galaxy 61a is the brightest and looks like an elliptical but is in fact a lenticular S0 type ie a disk galaxy without spiral arms. Galaxy 61d despite being the smallest actually has the brightest nucleus and was classified by Markarian as 761 in his catalogue of galaxies with excessive UV brightness.

    a = NGC 4169 S0
    b = NGC 4173 Scd
    c = NGC 4175 Sbc
    d = NGC 4174 S0-a

    Image details:

    • Date: 30th March 2013
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: 3.33 hours (10 x 20 mins) with CLS filter (RCOS) plus 3.33 hours (20 x 10 mins) RGB with Takahashi FSQ106/Canon 40D

    KEY

    NGC691

    The Box (Hickson 61)


    APRIL 14th, 2013

    Dwarf Spherical Galaxy Leo II (Harrington-Wilson No2)

    Despite its insignificant appearance this is one of the most studied of dwarf galaxies. Why? Well Leo II is the second most distant dSph galaxy assumed to be orbiting the Milky Way (MW) and should therefore be in pristine condition, unaffected by interactions/encounters with our galaxy. Recent research by several groups have confirmed this e.g. “we conclude that this dSph is rather an isolated Local Group satellite that is falling into the MW regions and passing its (dark) halo for the first time (e.g., Chapman et al. 2007; Majewski et al. 2007.)” - LÉPINE et al. 2011. So probably not a satellite after all. It's distance is around 700,000 light-years.

    Perhaps the best image of this object was taken 8.2 metre Subaru Telescope (Komiyama et al 2007). They detected over 80,000 stars down to magnitude 26. Koch et al (2007) estimated “the mass-to-light for Leo II to lie in the range 25 to 50. This is, in conjunction with the flatness of the dispersion profile, is striking evidence that Leo II is a dark matter dominated system”.

    Never going to be a showpiece object, I was pleased to be able to record it fairly clearly. I would estimate the stars in Leo II in my image to be around magnitude 19 to 21. They are also reasonably well resolved as the star density in this galaxy is very low.

    Image details:

  • Date: 29th March 2013
  • Telescope: RCOS 12.5 inch at f/9.
  • Camera: Apogee Alta U9.
  • Exposures: 3 hours (9 x 20 mins) with CLS filter (RCOS) plus 3 hours (18 x 10 mins) RGB with Takahashi FSQ106/Canon 40D
  • LeoII

    LeoII


    MARCH 30th, 2013

    Comet Panstarrs (C/2011 L4) over Blackpool Tower

    It's official - it's been the cloudiest March since the 1920's. But on the 27th March the skies cleared to the west - well they did for long enough to get some images. By about 8:15pm a line of clouds, just appearing in the top right of my main image, obscured the comet again.

    Because Panstarrs was low in the sky I had to travel to somehwre high. I chose Anglezarke (near Rivington) as it provides a clear view of the north-western horizon. However, following heavy snow falls this was a bit tricky with drifts towering above my car on the road sides. I made the trip with a colleague (Dean) and we were able to easily see the comet with his binoculars although it was hardly a naked-eye object at, I would estimate, magnitude 4.

    The mobile set-up I used was a battery driven Bolton Tracker mount. I choose a 50mm lens as I had worked out this would fit in both the comet and the Lancashire plain towards Blackpool. The Comet turned out to be a bit smaller than predictions so perhaps a longer lens would have been better. The close-up to the right was again with the 50mm lens just before some clouds arrived.

    Image details:

    • Date: 27th March 2013
    • Telescope: Bolton Tracker
    • Camera: Pentax 50mm lens + Canon 20Da
    • Exposure: Main 1 x 16 seconds + 1 x 9 seconds.
    • Exposure: Close-up - sum of 5 exposures 9 - 20 seconds

    Moorsel Chart

    NGC691

    Comet Panstarrs with Blackpool Tower on the horizon.


    MARCH 24th, 2013

    Gemini with the Bolton Astronomical Society Canon 300D

    Just when you think the weather cannot possibly get worse it does. March has been clouded out apart from a few gaps here and there.

    I recently acquired for our society a modded Canon 300D at a very reasonable price. It has had the deep-red blocking filter replaced making it very sensitive to the important H-alpha nebula emission line. This was the first test I managed with it - just enough time to show that it performs well. If you compare this to the image of Akira Fujii then it becomes obvious that the camera's H-alpha perfomance exceeds that of the camera used by this well-known astro-photographer. The bright (red) nebula Sh2-252 has recorded more prominently and even the smaller Jellyfish Nebula is obvious (between the two yellow/red stars). This gives an indication of the superb H-alpha sensitivity of this modded camera. The camera is for loaning out to members contemplating making a start in imaging.

    • Date: 10th March 2013
    • Telescope: Bolton Tracker
    • Camera: Canon 300D (modded) + 28mm Pentax lens @ f5.6
    • Exposure: 24 minutes (6 x 4 minutes) using IDAS LPR filter.
    Gemini

    Gemini


    MARCH 17th, 2013

    Planetary Nebula Abell 24 (PK 217+14.1 )

    I had long needed a deep-sky object in Canis Minor but it is not renowned for any spectacular objects. However, Abell 24 looked promising and turned out to be surprisingly bright given it is almost totally ignored.

    Very little information available on this object but I did find a paper by C.T. Hua and S. Kwok (Astron. Astrophys. Suppl. Ser. 138, 275-297 (1999)). The following is an (edited) extract from their paper. The H-alpha and [N II] images of Abell24 show two strong elongated E-W lobes with a fragment of (W-side) arc which could be part of a helical structure. The [N II] image, noticeably larger, displays a double shell with remarkable radial structures outwards. These jet-like structures are similar to those observed in the [N II] image of NGC 6543 (HST archives, program 5403, P. Harrington, P.I.). The patchy lane in the north shows up even more sharply. The two bright lobes could be the "waist" of a bipolar PN, with the underlying emission being the projection of two bubbles on top and below the waist. The jet-like radial structures, not apparent in wide bandpass images of Manchado et al. (1996, p. 125), are clearly seen in the NE and SW directions.

    Note regarding the prominent [N II} emission referred to by Hua & Kwok: the bandpass of most H-alpha filters (including mine) includes as well the close-by [N II] emission. Only filters with an extremely narrow bandpass can discriminate these two different emissions. Strictly normal H-alpha filters should be described as H-alpha + [N II}. This is one object that would benefit from 3nm Ha and 3nm NII filters perhaps revealing those "jet-like structures" - but at nearly £1000 each I'll pass this time!

    Image details:

  • Date: 18th & 28th February 2013
  • Telescope: RCOS 12.5 inch at f/9.
  • Camera: Apogee Alta U9.
  • Exposure: Total 5 hours with H-alpha + [NII] and OIII filters.
  • NGC891

    Abell 24


    MARCH 10th, 2013

    Christmas Tree Cluster, Cone Nebula and VdB 78

    Pushing my luck shooting under strong moonlight but with so few clear nights this winter I took a chance. This is the last of the sequence of images with the 300mm lens and it is now back inside until next winter.

    Several objects of note in this widefield view. The Christmas Tree Cluster is left of centre and surrounded by (bluish) reflection nebula. Below this is the Cone Nebula NGC 2264. The cone's shape comes from a dark absorption nebula of cold molecular hydrogen and dust in front of the bright emission nebula. The faint but rich cluster just below centre is Trumpler 5 (Collinder 105). This open cluster is extremely old at 3 billion years. To the right is blue reflection nebula Van den Bergh 78. Trickiest of all to spot is Hubble's Variable Nebula NGC 2261. Looking a bit like a tiny comet, it is located near to the bottom about a third the way in from the left.

    Image details:

  • Date: 17th February 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 40D
  • Exposure: 24 x 10 mins with UHC filter.
  • Christmas Tree Cluster

    Area around the Christmas Tree Cluster


    MARCH 3rd, 2013

    Rosette Nebula (Nebula: NGC2237-9; Cluster: NGC2244)

    Weather as normal meaning 3 separate nights needed to get a decent signal of this popular object. I shot the nebula off-centre in order to record the faint east (left) and north (top) extensions.

    The Rosette Nebula (Caldwell 49) is a large cloud of dust and gas with the open cluster NGC 2244 (Caldwell 50) at its centre. This young cluster has formed from the nebula and has created the central cavity. Radiation and stellar winds from the hot young stars within the cluster have blown the remaining material outwards. UV radiation from the hottest stars causes the nebula to shine. Research by Schneider et al. (1998) supported this scenario. Located in Monoceros.

    Image details:

  • Date: 6th, 15th & 16th February 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 40D
  • Exposure: 22 x 10 mins with UHC filter.
  • Rosette nebula

    Rosette Nebula


    FEBRUARY 17th, 2013

    IC405, 410 & 417 (Sh2-229, -236, -234)

    Our shocking weather continues and it took no less than 4 separate nights to get barely enough signal for this group of objects. We simply don't seem to get cloud free nights any more.

    A group of disparate nebulae at different distances and different origins. The Flaming Star Nebula (right) is a foreground object surrounding and illuminated by the variable star AE Aurigae. This star has a very high proper motion and is classed as a runaway star having been ejected from the Orion region. IC410 on the other hand (lower left of centre) is a background emission nebula illuminated by the open cluster NGC 1893. The third fainter nebula (upper left) is also in the background and is known as the Spider.

    Image details:

  • Date: 30th January, 1st, 2nd and 6th February 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 40D
  • Exposure: 22 x 10 mins with UHC filter.
  • Flaming Star

    IC405, 410 and 417


    FEBRUARY 3rd, 2013

    Californian Nebula, NGC 1499

    A return to a familiar target but this time using the Pentax 300mm lens. The plan was for 4 hours of exposure - 2 hours before the meridian and 2 hours after - but the last hour's worth was too light polluted to be used - a mist had rolled in. I find a meridian flip worth the effort as it averages out the fixed pattern noise of the 40D - the camera is upside down for the second sequence of images.

    Discovered by E. E. Barnard in 1884, this bright emission nebula in Perseus is easy to image but the outer reaches require long exposures. The star most likely to be ionising the nebula is the bright, hot & blue Xi Persei (below middle & right a bit)

    Image details:

  • Date: 14th January 2013
  • Telescope: Pentax 300mm lens at f/4
  • Camera: Canon 40D
  • Exposure: 18 x 10 mins with UHC filter.
  • California nebula

    NGC 1499


    JANUARY 27th, 2013

    Barred Spiral Galaxy NGC 1530

    In Camelopardalis is possibly the most spectacular barred spiral in the northern hemisphere. Despite being around 120 million light years away much detail is visible which gives a clue that this is an intrinsically large galaxy.

    NGC 1530 has a prominent bar with two wide open spiral arms originating from its ends. There is a lot going on in this galaxy and its most unusual feature is a bright mini-spiral ("nuclear spiral") at its core and orientated roughly perpendicularly to the bar (see inset). One of the most researched galaxies with several papers devoted to it and particularly focusing on gas inflow into the bar and nuclear region.

    Image details:

  • Date: 12th January 2013
  • Telescope: RCOS 12.5 inch at f/9.
  • Camera: Apogee Alta U9.
  • Exposure: 8 hours: 12 x 20 mins with CLS fiter (RCOS) plus 24 x 10 mins RGB with Takahashi FSQ106/Canon 40D
  • NGC891

    NGC 1530


    JANUARY 20th, 2013

    Asterism: Klingon Battlecruiser

    It's bad news if you see one of these coming towards you! In reality it is open cluster NGC 1662 but it does bear an uncanny resemblance to a Klingon Battlecruiser of Star Trek fame. Russell Sipe (Sky&Telescope, February 2005) was first to spot that the stars fitted the running lights of the battlecruiser (D7 Class). Not to be confused with a Romulan Warbird!

    NGC 1662 is a young open cluster situated in the direction of the galactic anticenter and relatively distant from the galactic plane. This large distance from the plane may seem surprising for such a young cluster and suggests that the formation mechanism could have been the collision of a high velocity cloud with the gas of the galactic plane. (Ref: Dias at al., Astronomy & Astrophysics 2000).

    Image details:

  • Date: 8th & 12th January 2013
  • Telescope: RCOS 12.5 inch at f/9.
  • Camera: Apogee Alta U9.
  • Exposure: 7 x 5 mins with CLS fiter (RCOS) plus 6 x 5 mins RGB with Takahashi FSQ106/Canon 40D
  • NGC1662

    NGC 1662


    JANUARY 13th, 2013

    Galaxies NGC 678, 680, 691, 694 & IC167

    Another interesting galaxy group this time in Aries. Again, on the basis of their motions, this is a group that supports the existence of dark matter. Moorsel (1988 Astronomy & Astrophysics) investigated the group and concluded the observable material only amounts to about 10% of the group's total mass. Distance to the group is around 100 - 125 million light years.

    See Moorsel's H1 map (right) for a key to which galaxy is which. Edge-on spiral galaxy NGC 678 and elliptical NGC680 (top right) are interacting with each other and show obvious distortions. NGC 691 (bottom) is a face-on classic SA type spiral and IC167 is the very open barred spiral towards the left.

    The image was taken on a very poor night - even by Lancashire standards - with the sky getting more and more orange as the night progressed.

    Image details:

    • Date: 13th December 2012
    • Telescope: RCOS 12.5 inch at f/9.
    • Camera: Apogee Alta U9.
    • Exposure: 12 x 15 mins with CLS fiter (RCOS) plus 12 x 15 mins RGB with Takahashi FSQ106/Canon 40D

    Moorsel Chart

     

    NGC691

    NGC 678, 680, 691, 694 & IC167


    JANUARY 10th, 2013

    Galaxies NGC672 & IC1727 (VV338)

    Interesting pair of galaxies located in Triangulum that support the evidence for dark matter (see later). They are of uncertain distance but certainly dwarf and relatively local (<32 Mly).

    The NGC 672/IC 1727 group consists of six members: the NGC 672/ IC 1727 galaxy pair (VV338 pair) and four more nearby dwarf Irregular galaxies. NGC 672 was classified Sc+ (Holmberg 1958) and later as SBc (de Vaucouleurs et al. 1976). IC 1727 was classified by the same authors as IrrI and SBm. Recent research by Zitrin & Bosch (2008) studied a string of galaxies comprising NGC 672/IC 1727 group, the NGC 784 group and several other galaxies in the same vicinity with similar redshifts. They proposed that the observational evidence argued in favour of interpreting the galaxies as being located along a dark matter filament that is itself located in a low-galaxy-density region and is accreting intergalactic cold gas focused by the filament.

    Image details:

  • Date: 10th December 2012
  • Telescope: RCOS 12.5 inch at f/9.
  • Camera: Apogee Alta U9.
  • Exposure: 18 x 15 mins with CLS fiter (RCOS) plus 18 x 15 mins RGB with Takahashi FSQ106/Canon 40D
  • NGC891

    NGC 672 and IC1727


    JANUARY 6th, 2013

    Asterism: David's D

    OK not its real name, that's Collinder 21, but when I came across this grouping I thought it good enough to deserve a name! It does look a bit like a capital "D".

    Following research by Sandro Villanova et al., this group was found (on the basis of proper motions and radial velocities) not to be the remnant of an open cluster but a chance alignment of brightish stars. You don't actually need 4.5 hours to image this object - it just so happened I was imaging nearby galaxies with the RCOS which do need that long.

    • Date: 10th December 2012
    • Telescope: Takahashi FSQ-106 (4-inch Refractor)
    • Camera: Canon 40D.
    • Exposures: 4.5 hours with UHC filter (18 x 15 minutes).
    California

    Collinder 21


    JANUARY 1st, 2013

    Edge-on Galaxy NGC 891

    Around 30 million light-years away in the constellation Andromeda, this dramatic edge-on spiral galaxy looks very much like our own Milky Way. It has a flat thin galactic disk and a central bulge divided down the middle by a prominent dark dust lane. Remarkably obvious at this distance are filaments of dust that extend hundreds of light-years above and below the center line. This dust is thought to have been blown out of the disk by supernova explosions and/or intense star formation activity.

    Image details:

  • Date: 9th December 2012
  • Telescope: RCOS 12.5 inch at f/9.
  • Camera: Apogee Alta U9.
  • Exposure: 12 x 15 mins with CLS fiter (RCOS) plus 12 x 15 mins RGB with Takahashi FSQ106/Canon 40D
  • NGC891

    NGC 891


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