Astroblog

Wednesday, April 12, 2017

More comet C/2015 ER61 goodness (8 April 2017)


Comet C/2015 ER61 on APril 8 at 4:41 AEST. Image is a stack of 15 x 60s greyscale images from iTelescope T13 registered and stacked in comet mode of DeepSky Stacker. Click to embiggen	Same images registered and stacked in ImageJ, then a SUMMED Z projection applied. Click to embiggen

Comet C/2015 ER61 is fading after its outburst, but I got some nice sequence of it via the remote iTelescopes (here it's been mostly clouded out). I've been playinng with DeepSKy stacker to see if I can better comet tail resolution than I can with ImageJ. My current attempts with both are pretty meh.

See my previous image here.

Labels: C/2015 ER61, comet, iTelescope

# posted by Ian Musgrave @ 9:46 pm 0 comments

Saturday, April 08, 2017

My First Image of Comet C/2015 ER61


Comet C/2015 CR61 taken on 6 April at 5:05 ACST (5 April 19:35 UT). Stack of 10 x 15 second images 400 ASA. Canon IXUS. Stacked in DeepSky Stacker	Comparison chart of the same area of sky showing comet location on the 6th

On my first night that I found comet C/2015 CR61 I took some pictures, they didn't come out so great, but here is the best stack I could come up with for historical purposes. Visually it was very easy to see in 10x50 binoculars, much brighter than it appears in this picture (smeared due to Earth's rotation).

Labels: astrophotography, C/2015 ER61, comet

# posted by Ian Musgrave @ 4:47 pm 0 comments

My First Telescopic Image of Comet C/2015 ER61

C/2015 ER16 imaged through iTelescope T13 on the morning of 8 April at 4:50 AEST. Stack of 10x60 second colour images (Bin 2) stacked in ImageJ and MEDIAN Z-projection used (click to embiggen).

Weather at the SSO finally cleared so I was able to get this image with the iTelescope T13 remote telescope.

The head is overexposed to show the tail more clearly. While not as impressive at this image (my image is rotated at 90's to this one, and is a much narrower field of view), it isn't too bad at all.

Labels: C/2015 ER61, comet, iTelescope

# posted by Ian Musgrave @ 3:58 pm 0 comments

Wednesday, April 05, 2017

Comet C/2015 ER61 PanSTARRS is in outburst, seeing it from Australia

Location of comet C/2015 ER61 (indicated by the cross) looking east as seen from Adelaide at 5:06 ACST (90 minutes before the sun rises). Similar views will be seen elsewhere in Australia (and most of the southern hemisphere) at the equivalent local time (90 minutes before the sun rises). Click to embiggen

Another comet has just dramatically brightened, unlike C/2017 E4 Lovejoy this time the comet favours us in the southern hemisphere.

Comet C/2015 ER61 is confirmed to be in outburst, with reports of magnitudes between 7.4 and 6.5, up from a pre-outburst level of 8.4.

This means that the comet should be readily visible in binoculars in the early morning sky, and a good target for southern amateurs who can get up before dawn.

Some nice pre-post image comparisons are here
http://cometografia.es/2015er61-panstarrs-20170404/ and here https://www.facebook.com/photo.php?fbid=438805123125824&set=gm.488200124683788&type=3&theater

Black and white printable chart of the path of comet C/2015 ER61 looking east as seen from Adelaide at 5:06 ACST (90 minutes before the sun rises). Similar views will be seen elsewhere in Australia (and most of the southern hemisphere) at the equivalent local time (90 minutes before the sun rises). Click to embiggen and print.

The comet is high enough above the morning horizon to be visible from around two and a half hours before sunrise ot 90 minutes before sunrise (astronomical twilight) after this the brightening skies will make to comet difficult to see.

Black and white printable chart for use with binoculars, the large circle is the field of view of 10x50 binoculars. The chart has the same orientation as the spotters map above, with the bright star Altair marked on both maps . Click to embiggen and print.

The comet is realtively easy to find, being almost exactly between the bright stars Altair and Fomalhaut, the two brightest stars in the eastern morning sky, on the border between Capricorius and Aquarius. Currently the comet is is between the moderately bright stars theta (𝛩) Capriconii and epsilon (𝜖) Aqaurii. The comet will track down the Aquarius/Capricornii border with plenty of good guide stars (see binocular chart above). It should be a reasonable target for the rest of the month.

Black and white printable chart for use with telescopes, in equatorial mount orientation use the stars iota (𝜄) Capricornii and nu (𝜈) Aquarii from the binocular chart for orientation. Click to embiggen and print.

The comet is within wide field view of globular cluster M72 and open cluster M73 over the next two days, and the Saturn Nebula on the 9th.So this should be good for telescopic observation.

Labels: C/2015 ER61, comet

# posted by Ian Musgrave @ 10:01 pm 0 comments