Observing Comet Iwamoto

Reports for 2019
User avatar
Apollo XX
MSSF Coordinator
Posts: 2448
Joined: Sun Jul 11, 2010 8:11 pm

Observing Comet Iwamoto

Unread post by Apollo XX » Fri Feb 22, 2019 10:56 am

Evidently the third time is the charm, as on my two previous attempts to see this short-timer for us but otherwise long-period comet I came up with nil. The sky was good last evening though, and it gave up the goods. C/2018 Y1 Iwamoto is a recently discovered long period comet that won't be back for well over 1,000 years, so this is it - see it or bust. Right now it's hovering between 7th and 8th magnitude, but as with all things diffuse it seems much dimmer in the eyepiece. I couldn't see it in 10x50 binoculars, but in the eyepiece of a 10" telescope it was a nice fuzzy patch. Just coma, no discernible head. Fast mover - very clear movement in a short period of time. All in all a very nice visual observation indeed.

Iwamoto Log Feb21'19.jpg
Iwamoto Log Feb21'19.jpg (518.16 KiB) Viewed 749 times
Last edited by Apollo XX on Fri Mar 01, 2019 6:39 pm, edited 1 time in total.
Mike M.
User avatar
Apollo XX
MSSF Coordinator
Posts: 2448
Joined: Sun Jul 11, 2010 8:11 pm

Re: Comet Iwamoto Visual Observation

Unread post by Apollo XX » Wed Feb 27, 2019 3:38 pm

One of the things I like to do sometimes is compare my sketching at the eyepiece to the known star layout through the use of charts/planetarium programs and images. Something I'm not bad at; plotting star positions as I see them in the eyepiece. Not perfect, but usually I have a fair rendition of what is really is. Something I'm not good at; rendering comparative star brightness. I especially struggle to depict dim stars in a comparative manner across the field of view. Most of the stars in my sketches look like they're the same brightness, which of course they're not.

Here's a comparison of my latest sketch, that of Comet Iwamoto from last week. I've circled the stars I plotted in red on the screen capture of the area as seen in the program Stellarium:
Iwamoto Comparo.png
Iwamoto Comparo.png (280.49 KiB) Viewed 734 times
Mike M.
User avatar
Apollo XX
MSSF Coordinator
Posts: 2448
Joined: Sun Jul 11, 2010 8:11 pm

Re: Comet Iwamoto Visual Observation

Unread post by Apollo XX » Wed Feb 27, 2019 3:52 pm

I got out yesterday evening with my custom chart and my 12.5" Newtonian to take another look at Iwamoto before it gets too dim to be practical. I ventured out into the icy cold abyss shortly after dinner to take a stab at it, and I was pleased as punch to find the comet almost exactly where the Sky Live https://theskylive.com/c2018y1-info site had predicted it would be. I've had very good luck with them. I think they're using the JPL ephemeris data. Anyway, I was looking from just before 8pm to just after, and I didn't dilly-dally too much with anything else due to frozen fingers. Damn, it was cold! :shock:

Here's about what I saw. Either the horrendous seeing impaired the view or the comet is dimming rapidly, because it was significantly fainter than my view just 5 days ago with a 10" scope.
Iwamoto Feb26 730pm.png
Iwamoto Feb26 730pm.png (93.37 KiB) Viewed 734 times
Mike M.
User avatar
Apollo XX
MSSF Coordinator
Posts: 2448
Joined: Sun Jul 11, 2010 8:11 pm

Re: Observing Comet Iwamoto

Unread post by Apollo XX » Fri Mar 01, 2019 6:50 pm

This will likely be my last stab at Iwamoto, at least for the next 1,341 years anyway. It was beautiful out last night so I broke out the iOptron Skytracker and my Nikon DSLR with a Nikon 55-200 zoom lens at 165mm, F5-ish, 40sec exposures, 42 of them. Stacked in DSS and post processed in GIMP. That's M36 to the left in the frame, with M38 to the upper right and Comet Iwamoto directly below M38 on the horizontal centerline. It's dim now and barely showed up in the single frames. After this upcoming stretch of bad weather, I really can't see it being a practical observation any more. It was fun though while it lasted.
36-38-Iwamoto Feb28'19.png
36-38-Iwamoto Feb28'19.png (1.21 MiB) Viewed 727 times
Mike M.
User avatar
Dr. Powell
10+ Years Member
Posts: 299
Joined: Tue Jan 20, 2009 11:24 pm

Re: Observing Comet Iwamoto

Unread post by Dr. Powell » Sat Mar 02, 2019 5:33 pm

Great observing report, Mike. Along with a good written narative, you add photos and diagrams so we can follow along with you visually. It really helps.
Mike
Mark Gibsonian 6" Newtonian Scope with a Spence mount.
16 X 50 Binoculars
60mm Bushnell Refractor
Jason Comet Hunter
5 1/4" Meade Reflector
Post Reply