Monday, March 28, 2016
Comet 252P in the tail of the Scorpion (morning, 26 March 2016)
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| 252P/LINEAR taken at 5:00 am AEDST 26/3/16. The image is a stack of 15x 60 second luminance exposures from iTelescope T12 at Siding Spring Observatory. MEDIAN Z projection used on the stack. Click to embiggen. | Same as before but a MAX Z projection on 8 of the 15 frames used to show the track of the comet. Click to embiggen. |
Comet 252P remains elusive for me from my home. The morning of the 26th it was just near Lesath and Shalula, the two bright stars in the sting of the Scorpions tail (and the two bright stars in the images above). However it was raining here in Adelaide. Fortunately iTelescope at Siding Spring Observatory was clear, and I was able to get these shots of comet 252P.
I used a MEDIAN Z projection registered on the comet to bring the comet out from the background stars, and a MAXIUM Z projection with the images registered on the stars to show the movement of the comet.
Labels: 252P, comet, iTelescope
Comet 252P and the Butterfly Cluster (27 March 2016)
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| 252P/LINEAR taken at 4:50 am AEDST 27/3/16. The image is a stack of 6x 60 second luminance exposures from iTelescope T12 at Siding Spring Observatory. MAX Z projection used on the stack. Click to embiggen. | Same as before but the images are SUMMED in the Z projection. Click to embiggen. |
The weather has been cloudy here, and I only got a brief glimpse of the tail of Scorpius through the cloud at 5:00 am on Easter Sunday before it really socked in. Fortunately iTelescope at Siding Spring Observatory was clear, and I was able to get these shots of comet 252P near the Butterfly Cluster. 6 x 60 second images were stacked in ImageJ and then I experimented with different Z projections to bring out the nebula and dark globules around the Butterfly Cluster (M6). On I used MAX, maximum intensity for each image and the other I simply SUMMED the images. The comet is a bit overexposed, but the surrounding territory comes out quite nicely.
Labels: 252P, comet, iTelescope
Friday, March 25, 2016
Comet 252P Amongst the Clusters of Scorpius and Ophiuchus (25 March - 1 April)
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| Location of comet 252P from 26-30 March as seen from Adelaide at 2:00 am ACDST. Similar views will be seen elsewhere in Australia at equivalent local time. Click to embiggen | Binocular scale view of comet 252P on 27 March when it is close to the Butterfly cluster (just below the comet) as seen from Adelaide at 2:00 am ACDST. Similar views will be seen elsewhere in Australia at equivalent local time. Click to embiggen |
The is good news and bad news about Comet 252P.
Good news: It has passed its closest approach to Earth and is still bright. While potentially (just) visible to the unaided eye, the bright Moonlight means that it will be a binocular or telescope object for most people.
From the 25th to 30th March 252P will be in a cluster and nebula rich region in between the Scorpion's tail and Ophiuchus. There are so many potential objects it is nearby that it would take ages to list them, and a binocular scan will bring delight at every view.
The most notable encounter is one on the 27th when the comet is within 2 degrees of the Butterfly cluster (M6) and 5 degrees from Ptolmey's cluster, with many smaller clusters closer. At this time the comet is rising around 10:30-11:30 pm in Australia, but the best time to observe is from around 2-3 am on, when the comet has cleared the murk of the horizon. In the Northern Hemisphere, the comet should now be visible above the horizon around Astronomical twilight in the morning.
Bad news: Unfortunately, while the Moon is waning (Yay) it is close the 252P for most of this time, less than 40 degrees from the the comet on the 27th, and comes closer as the days progress. It is also rising before, or just after the comet. So we get no relief from Moonlight. You will definitely need to dark adapt your eyes to have a good chance to see the comet.
The Moon is within 6 degrees (a hand-span) from the comet on the 30th and 31st. This will make the comet extraordinarily difficult, if not impossible, to see, with ordinary binoculars and telescopes.
If you have a telescope with narrowband filters imaging will probably be okay up to 29-31 March, the even though waning the Moon will be sufficiently close to significantly interfere.
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| Black and white chart of the path of comet 252P/LINEAR suitable for printing. The chart shows the view south at 3:00 am local time. The circle is the field of view of 10x50 binoculars. Click to embiggen and print. | Black and white chart of comet 252P/LINEAR on 27 March suitable for printing and for use with binoculars. Use in conjunction with the sky map to the left. The circle is the field of view of 10x50 binoculars. Click to embiggen and print. |
Printable PDF versions of the above maps, spotters chart and binocular chart at 3:00 pm ACDST. Use a red torch, or a normal torch with red cellphane over the end so as to not destroy your night vision. For more help with dark adaptation see here.
More good news: There are good guide stars now. tonight/early morning 26th the two stars that form the sting of the Scorpions tail, Lesath and Shalula, point to the comet. On the 27th the comet is above M6, the butterfly cluster, which is obvious in binoculars. On the 28th, star hopping down two from bright Theta Ophiuchus will bring you to the comet.
Labels: 252P, binocular, comet, telescope
Monday, March 21, 2016
My First Visual Observation of Comet 252P (21 March)
I finally saw the comet myself this morning (21 March) at 5:00 am in 10x50 binoculars from suburban Adelaide.
I could not see it with the unaided eye. In binoculars it was very dim to my eyes but definitely there.
I had fairly good guide stars this time, as opposed to the previous morning when I tried and could not see it. I had familiarised myself with the guide stars in the evening. However, the location of the comet low to the horizon, and the sky glow from the Moon combined to make the comet invisible in the evening
By morning the comet was well above the horizon, and the Moon was sufficently low it did not interfere much. I could clearly see the Milky Way (although it was dim), and the comet pooed right out at me (although it over lapped a brightish star). Tried to estimate magnitude but there were no suitable reference starts close by.
Toning once more there are no clear guide stars in the vicinity to help me locate the comet. Sigh.
Labels: 252P, binocular, comet
Friday, March 18, 2016
Finding Comet 252P 19-25 March (NOT April)
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| Location of comet 252P from 19-25 March as seen from Adelaide at 23:00 ACDST. Similar views will be seen elsewhere in Australia at equivalent local time. Click to embiggen | Animation of the comets path through the sky from 19-25 March at 11pm. |
UPDATE: Saw the comet myself this morning (21 March) at 5:00 am in 10x50 binoculars, but not with the unaided eye from suburban Adelaide. In binoculars it was very dim to my eyes but definitely there. I had fairly good guide stars this time, as opposed to the previous morning, and I had familiarised myself with them in the evening.
Comet 252P continues to astonish with its unprecedented increase in brightness. It has been reported to be (just) visible with the unaided eye under dark sky conditions. Comet 252P/ LINEAR comes closest to Earth on March 22 at 00:15 AEDST, At this time it is very close at around 10 Earth Moon distances away, and should be at its brightest. Unfortunately the nearly full Moon will strongly interfere with seeing the comet. Especially as the comet is quite diffuse, it will be easily washed out.
As well, because it is so close to Earth, the comet is moving very fast, you should see it actually move over the course of the night. However, this means that astrophotography will be quite difficult as the comet will be hard to track.
On the night of the 19th, looking south, if you draw a line from the long axis of the Southern Cross to the star Achernar, then draw a line perpendicular to this from Canopus, the comet will be almost at the intersection of these two lines. On the 20th, the comet will be on a line drawn from alpha Centauri (Rigel Kent) to the star Achernar, closet to Rigel Kent. While the comet will be very hard to see with the unaided eye, strong binoculars or a telescopes finder-scope should pick it up.
After this, until the 25th when it reaches Scorpio, there are not really any good guide stars to the comet (but see the binocular comet chart below, okay so on the 21st and 22nd it is close to a Trianguli Australis, but this is not a very obvious star).
Over the next few days the comet get progressively lower in the evening sky, but becomes better to view in the morning. On the mornings of the 25th-28th the comet crosses the tail of the Scorpion and Sagittarius, coming close to a number of clusters and nebula. How bright the comet will be then is unknown, but hopefully it will be binocular bright as the Moon fades and its passes through the nebula. That should be spectacular.
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| Black and white chart of the path of comet 252P/LINEAR suitable for printing. The chart shows the view south at 10:00 pm local time. The circle is the field of view of 10x50 binoculars. Click to embiggen and print. | Black and white chart of the path of comet 252P/LINEAR suitable for printing and for use with binoculars. Use in conjunction with the sky map to the left. The circle is the field of view of 10x50 binoculars. Click to embiggen and print. |
Labels: 252P, binocular, comet, telescope
Thursday, March 17, 2016
Comet 252P/LINEAR close to the Large Magelleanic Cloud Tonight (17 March 2016)
Comet 252P is still brightening rapidly, with the last reported magnitudes being around 6.5. While this is just below the threshold of visual detection, the comet is diffuse and extended, and will be much harder to see than the magnitude suggests.
Last night in suburban Largs, with good visibility despite a waxing Moon, I was unable to see it with 10x50 binoculars, although it has been reported from darker skies with stronger binoculars. The Tarantula nebula was obvious though in my binoculars.
Tonight the comet is on the outer fringe of the Large Magelleanic Cloud. Despite the waxing Moon, if you have dark skies and wait until the Moon is low, then with decent binoculars or a small telescope you should see a fuzzy ball on the edge of the LMC.
Looking south, if you draw a line from the long axis of the Southern Cross to the Star Achenar, then draw a line perpendicular to this from Canopus, the comet will be around one binocular field up from the intersection of these two lines.
In binoculars or a finder scope, the fuzzy Tarantula nebula will be obvious at this location, the dimmer comet will be one or two fields to the east, near an obvious pair of stars.
Black and white chart of the path of comet 252P/LINEAR suitable for printing and for use with binoculars and finder scopes (with redlight torches). The circle is the field of view of 10x50 binoculars. Click to embiggen and print.The comet is moving very rapidly leading up to closest approach.
For those of you with ephemeris programs or programmable telescopes, the
MPEC one line ephemeris for Comet P252/ LINEAR
0252P 2016 03 15.2721 0.996074 0.673296 343.3158 190.9520 10.4233 20160402 17.5 4.0 252P/LINEAR
The comet will continue to brighten, but the rapidly brightening Moon will make it harder or see.
Labels: 252P, binocular, comet, telescope
Monday, March 14, 2016
My first shot of comet 252P/LINEAR
No idea how currently bright it is, cloud here keeps me from making visual observations. but from other observers it is now apparently between 6.5 and 7.0 so still brightening.
Labels: 252P, comet, iTelescope
Comet 252P LINEAR brightens rapidly, may be visible to the uniaded eye soon
Comet 252P/ LINEAR comes very close to Earth (around 10 Earth Moon distances away) on March 21 13:15 UT (March 22 00:15 AEDST).
252P passes through Pictor, Octanis and Scorpius and has its closest approach in Apis. The comet was predicted to have a maximum brightness of around magnitude 11.
However, comet 252P/ LINEAR has been reported to be anomalously bright, with reports putting it well above its theoretical maximum of magnitude 11. A recent report from Michael Mattiazzo has it at magnitude 8.2, and a more recent report from Chris Wyatt puts it at magnitude 7(!). Terry Lovejoy has seen it with 15x70 binoculars. While at magnitude 7 it theoretically should be readily visible in 10x50 binoculars, the fuzzy nature of the comet makes it harder to pick up. The comet appears to have a diameter of 23-24 arc seconds.
Currently the comet is brightening at around 1 magnitude per day! If it follows its current brightening it could be visible to the unaided eye in a few days, however, the brightening Moon will make seeing an extended, fuzzy object like this comet more difficult. Of course there is no guarantee it will continue to brighten.
Black and white chart of the path of comet 252P/LINEAR suitable for printing and for use with binoculars. The circle is the field of view of 10x50 binoculars. Click to embiggen.The comet is moving very rapidly leading up to closest approach. On the 16th and 17th (and part of the 18th) comet 252P will be close to the Large Magellanic Cloud. This should make for interesting viewing and some mice astrophotographs, if the Moonlight doesn't interfere too much.
For those of you with ephemeris programs or programmable telescopes, the
MPEC one line ephemeris for Comet P252/ LINEAR
0252P 2016 03 15.2721 0.996074 0.673296 343.3158 190.9520 10.4233 20160402 17.5 4.0 252P/LINEAR
Labels: 252P, binocular, comet, telescope
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