Archive

Posts Tagged ‘comet’

Comet Catalina – Now Visible in Binoculars

January 16, 2016 Leave a comment

800x

Above: Comet Catalina on 15/1/2016 at 23.31 pm from the back garden. Sony RX100, 28mm, F1.8, ISO 3200, 8 seconds. A crop of the image below.

Comet C/2013 US 10 Catalina will be at it’s closest approach to Earth on Sunday 17th January at about 110 million kilometres away. It is already speeding away from the Sun and back out of the Solar System and losing brightness fast. With a Full Moon coming up on January 24th this really is your last chance to see the comet with binoculars from your back garden as the moonlight will make it very difficult to see. I had a look last night in wonderful clear skies and the comet was easily visible in 8 x 30 binoculars.

The photograph above gives a pretty accurate idea of what you will see through binoculars. Look for a faint grey fuzzy splodge with a slightly brighter core to the left of the star Alkaid which forms the tip of the handle in the constellation Ursa Major (also called the Big Dipper, The Plough, The Saucepan).  If you are stepping outdoors from a brightly lit house your eyes will need 5 – 10 minutes to fully adjust to the dark conditions and resolve the faintest stars and the comet. Turn off all outside lights and don’t use torches as these will ruin the ability of your eyes to adjust and see fainter objects. Just stand and look at all the amazing constellations around you for a bit then zoom in with the binoculars and let your eyes become accustomed to the darkness. Scan the area to the left of the star Alkaid (use the finder chart below) and you should pick up the faint grey smudge of light that makes up the comet. Feast your eyes on this small object as it is the last time humans will see it. Catalina will never return due to its orbital path.

DSC053861280x

Above: The position of the comet to the left of the bright star Alkaid in Ursa Major 15/1/16 23.31 pm

comet-catalina-star-chart

Above: Finder chart courtesy of freecharts.com to help you locate the comet between the 15th and 22nd January

While you are out there under the stars do also take a look behind you to the south and the fabulous Orion constellation with the Hyades and Pleiades star clusters to the west of it. It was really glistening last night in a very dark and clear sky from our house.

DSC05392alt

Above: The constellation Orion to left with the Hyades (right of centre) and Pleiades (right) star clusters. Image taken 15/1/16 23.39 pm Sony RX100, 28mm, F1.8, ISO 3200, 8 seconds.

Advertisements

C/2013 US10 Catalina – A Christmas Comet

December 18, 2015 Leave a comment

Comet-Catalina2alt-1280-5-750

I last viewed Comet Catalina in August when it was only visible in the southern hemisphere. It is now visible low in the east during the early hours of the morning around 5am, but will be steadily gaining in height throughout December and January. It is currently magnitude 6 and easily seen in 8x or 10x binoculars as a faint grey smudge in the constellation Virgo.

The comet is displaying a couple of really nice, widely separated, tails at the moment with the fainter ion gas tail at the bottom, blown at high speed away from the direction of the Sun by the solar wind. The dust tail at the top is moving much more slowly away from the comet. Having been dislodged from it’s home in the Oort Cloud recently on a hyperbolic trajectory Catalina is making just one approach into the Solar System before vanishing back out and never to be seen again. The comet reached perihelion, it’s closest approach to the Sun, on November 15th and is now on the journey out.

Image taken 18/12/15 5.37am New Mexico time on iTelescope.Net T20. 4 x 300 sec Luminance. RA: 14h 17m 18.0s DEC: 01° 13′ 51″ (J2000). Stacked in DeepSkyStacker 3, Processed in Maxim DL5 and Photoshop CS2.

 

Comet C/2014 Q2 (Lovejoy)

August 16, 2015 Leave a comment

Comet C/2014 Q2 put on a superb show at perihelion (closest approach to the Sun) in mid January 2015 and I caught some images of it back in March 2015  when it was around magnitude 6.8. It is fading fast now as it leaves the Solar System, but can still be picked up in telescopes at magnitude 10.3. Here you can just make it out as a fuzzy ball of light at the centre of the image passing through space between the constellations of Draco and Bootes.

C2014Q2-2

Comet Lovejoy Orbit 13-8-15Orbit view showing the current location of the comet as it leaves the Solar System

Image taken 11.38 pm New Mexico Time (UTC -6) with iTelescope.net T3 (Tak TOA 150, SBIG ST-8300C One Shot Color CCD) 5 x 120 sec Lum.

Categories: Comets Tags: ,

Comet C/2013 US 10 (Catalina)

August 9, 2015 1 comment

Discovered by R.A. Kowalski and the Catalina Sky Survey in October 2013 C/2013 US10 is now at magnitude 7.5 and brightening. It is only observable in the southern hemisphere at the moment, but should be visible in the north from November. This photo shows the bright nucleus, the ion tail to the left and the finer dust tail rising vertically in the photo.

c2013-us10-4cropped2

Image taken 2.26am 10/8/15 using remote iTelescope T12 (Tak FSQ ED 106, Camera: SBIG STL-11000M) Siding Spring Observatory, Australia. 2 x 300 Luminance. Stacked and registered in DeepSkyStacker 3, Processed in Maxim DL 5 and Photoshop CS2.

Categories: Comets Tags: , , ,

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.

Comet C/2010 G2 Hill and update on SN 2011fe in M101

September 9, 2011 Leave a comment

During the early morning of 7th and 8th September I attempted to image Comet C/2010 G2 Hill which is very faint at approx mag 11 close to Lynx. On both occasions there were significant guiding errors with GRAS G7 in Spain which produced some very odd star trails. The comet only reaches a sufficient height for imaging on the GRAS telescopes after about 6.00 am Spanish time when the comet reaches 40 degrees above the horizon, so there may be some early twilight effects at play here.  GRAS telescopes generally cannot image below 30-35 degrees and atmospheric aberrations will be high below this level anyway.

The image below has been significantly cleaned up with all of the star trails removed. C/2010 G2 Hill appears as a faint smudge in the centre with a small diffuse coma. The comet is currently slowly brightening and should be visible in telescopes well into next year. GRAS G7 – 600 sec Lum/Deep Space Planewave 17″/FLI ProLine PL11002M

The supernova SN 2011fe in M101 (Pinwheel Galaxy) seems to have reached its maximum magnitude at around 10.0 or 9.9 according to the light curve provided on AAVSO. If you are thinking of imaging the galaxy now would be the best time !  Don’t forget that supernova SN 2011dh is still visible for imaging in M51 (Whirlpool Galaxy) too, but you will need to catch M51 early after sunset as it dips below 30 degrees altitude and into the murk by 10pm in the northern hemisphere. The current magnitude of SN2011dh in M51 is around 14.8

AAVSO light curve for SN 2011fe 9/9/11