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Archive for March, 2015

Comet C/2013 A1 Siding Spring glides past the globular cluster M92 29/3/15

March 30, 2015 Leave a comment

SidingSpringstackedcrop2altComet C/2014/A1 Siding Spring passing M92 (comet is faint grey fuzzy tail and coma to right of cluster)

Comet Siding Spring was discovered by Robert H. McNaught at the Siding Spring observatory in Australia on January 3rd 2013. Never one of the brightest comets, it reached a peak magnitude of 9 in December 2014 and is now fading as it moves out of the Solar System. Current magnitude estimates put it at 14.7, so you will only see this with large aperture telescopes.

I happened to notice it was passing the globular cluster M92 in Hercules in the early hours of yesterday morning and took this quick image as a record of its passage.

M92 was discovered by Johann Elert Bode in December 1777. It is 27,000 light-years distant and contains about 400,000 stars. Like most metal-poor globular clusters it is extremely old and current estimates put its age at 14.2 billion years, which is pretty much the age of our universe ! This cluster is often overlooked for the more famous and visually larger M13 cluster, but is a visually pleasing and interesting object nonetheless. Using just the eye a 4″ to 5″ telescope will resolve a few outer stars, but to resolve the whole cluster you will need a 12″ or larger telescope. The whole cluster resolves easily with digital imaging in wide view telescopes of 3″.

Image taken 29/3/15 3.58am New Mexico time (9.58am UTC) on iTelescope T20 (Takahashi 106mm, Camera: FLI ProLine PL11002M) RA: 17h 17m 00.0s DEC: 43° 26′ 00″ (J2000)

Orbital TrackCurrent orbital track location of comet C/2013/A1 (light blue line) as it leaves the Solar System

Chasing Comet C/2014 Q2 Lovejoy at dusk in moonlight – not recommended !

March 29, 2015 Leave a comment

Having somehow completely missed all of the best opportunities to image Comet Lovejoy I thought it was time to try this before the comet disappears below the horizon at dusk and becomes truly impossible to photograph.

To do that I needed time on the iTelescope T20 over in New Mexico. The problem is that I only had a 30 minute maximum window of opportunity to capture the data in 58% moonlight just after the sun had set and with the telescope rapidly approaching its low altitude limit of 25 degrees above the horizon ! In addition, as it was impossible to reserve time 2 hours before using the telescope, I had to run the gauntlet of someone else starting up a short random imaging session on the same telescope before I could get the session parameters set up and sent to the server. In the end I managed to run off two 5 minute exposures in black and white, but the following colour RGB session failed as I hit the telescopes altitude limit before the session was complete – aaargh ! The light from the moon and remaining faint daylight had  a pretty shocking effect on the raw .FITS files when I opened them up. There was a huge grey mist-like gradient across the images and numerous passing aircraft trails too due to the wide view provided by the Tak 106 telescope. Just take a look at this raw image below to see what I mean – this is what most astrophotographers don’t show you !

Before-processingAbove: Raw image before cleaning up – messy! Note the very long comet tail though

Now for the processed images which I am pretty happy with given the problems mentioned above. A good example of how to rescue things from a bad situation………

Lovejoy-wideWide view of comet Lovejoy after processing showing the long extended tail

Lovejoy4Detailed view of the coma and tail of comet Lovejoy

Lovejoy is fading in brightness from its maximum magnitude of 3.7 at perihelion in mid January to 6.8 now, but it is still visible with binoculars so take a look.  It was discovered by Terry Lovejoy in August 2014 and is currently travelling back out of the Solar System between the constellations Cassiopeia and Cepheus low in the north.

Lovejoy orbital pathCurrent orbital path out of the Solar System of comet Lovejoy (light blue line)

Images taken 28/3/15 8:30 am New Mexico time on iTelescope T20  Takahashi FSQ-ED 106, Camera  SBIG STL-11000M. 2 x300 sec, Bin 1, Luminance. RA: 01h 23m 18.0s DEC: 64° 40′ 09″ (J2000). Processed in MaxIm DL5, DeepSkyStacker 3, Photoshop CS2.

Supernova SN2015F in Galaxy NGC 2442 28-3-15

March 28, 2015 Leave a comment

ngc-2442-stacked4

I fancied a change of scenery after all of the recent solar activity of various sorts and ventured south of the equator this time. As many of you who read this blog will know I often like to take images of supernovae which briefly appear in distant galaxies and the current brightest supernova is SN2015F. I reserved some time at the iTelescope Siding Spring observatory in Australia and used their half metre T31 Planewave telescope to capture this image.

Supernova 2015F was discovered on 9/3/15 by Berto Monard. It is a Type Ia currently at magnitude 13.3 and is located within the intermediate spiral galaxy NGC 2442, more commonly known as the Meathook Galaxy, in the constellation Volans (southern hemisphere). The Meathook Galaxy lies 50 million light years away and was first discovered by John Herschel.

Type Ia supernovae are fairly common in galaxies with old star populations and are really useful for determining distances between objects and even the age of the universe. Type Ia’s are the result of a white dwarf star exploding in a binary star system due to complex gravitational interactions between the white dwarf and a much larger companion star. The white dwarf grows to approximately 1.4 times the size of the Sun and then becomes unstable and explodes, destroying the star completely.

Imaged 28/3/15 10.28pm Australia time (11.28am UTC) on iTelescope T31 CDK 500mm Planewave with FLI-PL09000 camera. 3×300 sec, Bin 1, Luminance, RA: 07h 36m 18.0s DEC: -69° 31′ 59″ (J2000). Processed in MaxImDL5, DeepSkyStacker 3 and Photoshop CS2.

The Sun 27/3/15 – Big changes on the limb and a few new sunspots

March 27, 2015 Leave a comment

diskproms2-15-03-27-15-36-5

Ha Disk

The splendid hedgerow prominence from yesterday has gone ! The magnetic field holding all of that plasma together became unstable and the material was ejected off into space at around 13:00 today. Things change fast on the Sun and that is why it is such a fascinating object to observe. The coronal mass ejection from this event is not predicted to have any major impact on Earth.

So what else is there to see ? Well there is a good smattering of feathery, curving filaments across the disk in Ha light and Active Region 2305 is smack in the centre, but not really putting on much of an energetic show. It has split onto three sunspots now and the CaK view shows up lots of other small spots and pores (2310, 2312 1and 2313)  extending off to the limb. In the east (east and west are inverted in the disk view above) there is one large prominence left on the limb.

hapromsclose-15-03-27-15-52 The single large prominence on the east limb

HaArclose-15-03-27-15-49-36Active Region 2305 in Ha light showing the filaments to the left and finer curving magnetic flux around the sunpsots

cakdisk-15-03-27-16-00-02vdThe Sun in CaK light showing active region 2305 at the centre and additional spots and pores

The Sun 26/3/15 – Active Region 2305 and a large ‘Hedgerow’ Prominence

March 26, 2015 Leave a comment

DiskandpromsHa view with large ‘hedgerow’ type prominence

Sunspot2305Active Region 2305 Sunspots in CaK light

Active region 2305 is near the centre of the sun and facing Earth which could give us some nice aurora if it flares. The region has a beta-gamma delta-magnetic field which is capable of producing the most energetic X-Class flares and if this area erupts in the next couple of days the ejected material could have a large impact down here.

Imaged with Coronado PST Ha (40mm) and Lunt Solar Cak wedge (100mm) with DMK41 camera.

Categories: Solar Tags: , , , , ,

Crescent Moon and Venus – 22nd March 2015

March 22, 2015 Leave a comment

DSC02531alt2The crescent moon descending through fog in the west with Venus above 8.10pm

Categories: Lunar, Planets

90% Solar Eclipse over Mid Wales 20th March 2015

March 20, 2015 2 comments

hadisk1alt23Above: Ha view with single sunspot region 2303 visible and some curving wispy filaments

The Sun is throwing an embarrassment of riches at me this week with a first ever view of the aurora on Tuesday night and now a perfect blue-sky view of the 90% solar eclipse from the front garden ! I was well prepared this time with all batteries charged up and a ‘Plan B’ mobile solution which could be powered from the car if the notorious local river fog blotted out the view. The weather conditions turned out to be perfect though with early cloud passing over from the north west leaving a clear blue sky completely through the eclipse event from first to last contact. The whole event lasted between 8.40am and 10.40am with maximum coverage at our latitude of just over 90% at 9.30am.

The neighbours gathered around close to the maximum and watched via the video footage on the laptop screen while I captured footage via the DMK41 mono video camera on the Coronado PST Ha and CaK scopes mounted on the EQ6 drive. It was a very pleasant event and everyone had a good view. There was a terrific quality of light at maximum with lots of long shadows cast across the landscape and a deep navy blue sky.

The images are all single frames selected from the 1000 frame footage of the videos as my stacking software (Registax 6) has issues with aligning points when both the sun and moon are moving relative to each other in the video footage. Even so I am very pleased with the results which make up a fine record of the event.

caksun1alt3Above: CaK View with Sunspot region 2303 visible

hadisk4alt

hadisk5maxaltAbove: 9:30am Maximum coverage for our latitude at just over 90%

hadisk6minaltAbove: Near last contact at 10:38am – just a small bite out of the sun at bottom left

haproms1alt2Above: Some fine prominences on the limb