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 Post subject: C/2012 K1 (PANSTARRS)
PostPosted: Fri Apr 04, 2014 7:06 pm 
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I've just realised that there will be another faint comet within CCD range for the next few months.
It's down at 9th magnitude at the moment, but at least it's visible in the evening sky, not just before dawn!
It's currently mid-way between Hercules & Bootes, but you can display it's current position from here: http://theskylive.com/planetarium?obj=c2012k1


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Tue Apr 15, 2014 3:28 pm 
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This is my first view of this comet, via the BRT Galaxy Cam this morning:
Attachment:
File comment: Comet PanSTARRS on 15-Apr. Stack of 3x 60-sec with C14 at f/5.3.
C2012K1_15apr.jpg
C2012K1_15apr.jpg [ 171.91 KiB | Viewed 6402 times ]

I've made a composite of the three 1-min exposures with their B, V & R filters.
The comet has moved slightly relative to the background stars over the three minutes, so this stack shows the stars appearing to trail slightly along a SW/NE axis.


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Wed Apr 16, 2014 6:40 am 
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Now I've got more of the tail in this single 120-sec exposure with no filters:
Attachment:
File comment: Comet PanSTARRS on 16-Apr. 120-sec with BRT Galaxy Camera (C14 at f/5.3)
C2012K1_16apr.jpg
C2012K1_16apr.jpg [ 206 KiB | Viewed 6399 times ]


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Sun Apr 20, 2014 8:10 am 
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Down here in the Wye Valley it was clear on Friday night and very mild, so I spent an hour outside with my DSLR camera and 10x50 binoculars, looking for the comet. It's still very faint at the moment, so even from this dark-sky sight I wasn't convinced that I could see it. But I set up my camera and telephoto lens (no light-pollution filter needed here!) on a tracking mount and took a series of 1-min long exposures. These was just a faint smudge visible at the comet's expected position, so last night I took a set of offset and dark-frames for calibration, and then spent a couple of hours processing them (this little netbook PC is OK for processing VGA webcam images, but struggles with the mega-pixel files from a DSLR!):
Attachment:
File comment: Comet PanSTARRS on Good Friday. 28x 1-min exposures over the course of an hour, taken using Pentax K110D with Pentax-A 135mm lens af f/6.3
C2012K1_18Apr.png
C2012K1_18Apr.png [ 368.54 KiB | Viewed 6371 times ]
I used my spreadsheet utility to extract the comet's tracking vectors, so that I could use the TRANS2 command in IRIS to register the images on the comet's position - hence the stars appear to trail across the field.
The CCD in my old Pentax is so noisy that I hat to limit my exposures to 1-min, with 1-min cooling-time between them, and still I had more than 10000 hot-pixels in the Master Dark-frame! Some of these residual uncorrected hot-pixels can be seen in the image as faint vertical lines (a useful measure of my declination drift!).

But the bonus of being out there whilst the camera was working autonomously was that I was able to observe the M51, M81 & 82 galaxies with my binoculars, and also saw a spectacular "fireball" meteor streak out of Bootes. :D


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Sun Apr 27, 2014 1:26 pm 
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Last night the BRT picked up the comet with it's wide-angle Cluster Camera :
Attachment:
File comment: Comet PanSTARRS just before midnight on 26-Apr. 3x 2-min with BRT Cluster Camera (180mm f/2.8 lens). Processed in IRIS.
C2012K1_26apr.jpg
C2012K1_26apr.jpg [ 341.24 KiB | Viewed 6294 times ]

It's currently moving between Bootes and Ursa Major, so is well-placed for Northern observers: high up in our evening skies (once it eventually gets dark).
I managed to catch it from home too last night, using my webcam on the back of the StarWave 80 (I just need to take some Dark-frames before I can complete the processing).


Last edited by rwilkinson on Mon May 05, 2014 10:07 am, edited 1 time in total.

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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Mon Apr 28, 2014 7:14 am 
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This is my image of the comet from Saturday night:
Attachment:
File comment: C/2012 K1 on 26-Apr. 52x 1-min with Philips SPC880 on StarWave 80ED at f/4.6.
c2012k1_26apr.jpg
c2012k1_26apr.jpg [ 82.29 KiB | Viewed 6287 times ]

The star-trails show how far it had moved in 52 minutes.


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Wed Apr 30, 2014 7:36 am 
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Here's another image taken from Tenerife last night using the BRT GalaxyCam:
Attachment:
File comment: Comet PanSTARRS on 29-Apr. IRIS composite of 120-sec + 3x 180-sec with C14 at f/5.3.
C2012K1_29apr.jpg
C2012K1_29apr.jpg [ 83.71 KiB | Viewed 6272 times ]
I've stacked a 2-min exposure using no filter with 3x 3-min exposures taken through the B, V, & R filters (guess which one is the brightest?)


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Sat May 03, 2014 9:24 am 
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Here's another composite using last night's data from the BRT Galaxy Camera.
In this case, the unfiltered image was taken before midnight and the BVR images an hour and a half later, so I had to account for the mount's meridian flip before I could align and stack the two sets of images.
So if you look carefully, you can see that each bright star has an elongated trail (of the three colour images) some way off to its left.
Attachment:
File comment: Stack of 4x 180-sec with BRT Galaxy Camera (C14 at f/5.3).
The overlay links the "clear" image of a bright star with its B, V & R filtered counterparts.

panstarrs_3may.jpg
panstarrs_3may.jpg [ 358.98 KiB | Viewed 6256 times ]


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Mon May 05, 2014 10:06 am 
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The comet was captured in two tri-colour BVR images from the BRT Cluster Camera last night: here's a stack of all the data:
Attachment:
File comment: C/2012 K1 on 5-May. 3x 180-sec + 3x 120-sec with BRT Cluster Camera (Nikon 180mm f/2.8 lens)
panstarrs_5may.png
panstarrs_5may.png [ 326.01 KiB | Viewed 6230 times ]


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 Post subject: Re: C/2012 K1 (PANSTARRS)
PostPosted: Tue May 06, 2014 8:55 pm 
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Here's the composite image (using the MOSAIC process in IRIS) of Comet PanSTARRS passing by the Whirlpool Galaxy on Sunday night, which I included in my talk this evening.
If you look carefully, you should be able to "see the joins" where the colour and monochrome images overlap:
Attachment:
File comment: Mosaic of two sets of BRT Cluster Cam images from 5-May-2014. 120-sec for M51, plus 3x 120-sec and 3x 180-sec for the comet.
m51_Pan.png
m51_Pan.png [ 399.61 KiB | Viewed 6207 times ]

As well as shifting the second image, I needed to rotate it by 3.4 degrees to get all the stars to line up between the two images.
Maybe this implies that the axis of their camera is 1.7 degrees off North, this error being doubled when a meridian flip occurs?


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