|
|
Thread Tools | Display Modes |
#10
|
|||
|
|||
Let's Photograph Comet 46P Wirtanen
On Sat, 22 Dec 2018 00:43:11 -0600, hleopold
wrote: On Dec 21, 2018, Chris L Peterson wrote Indeed, aperture is irrelevant. No amount of aperture can ever increase the surface brightness of an extended object beyond what we can see with our unaided eye. Given the size of this comet, it is best viewed at low magnifications, and therefore there's no advantage to more than just a few inches of aperture. (But aperture is critical to good imaging, as it allows for shorter exposures and therefore a better capture of this fast moving body.) I agree. As for the speed of this comet, I had noticed that in David’s 4 shot stack where he pointed out that it was not a tail but movement between the shots. I was really surprised to see that it had moved that far in, I believe part of a night. I realize that when they are close comets are normally moving quite quickly. Well depending on the geometry of course. But so surprising to actually see it in the sky, where things seldom move fast. Here's a quick and dirty animation (unprocessed raw frames) taken also on 17 December. These were 60-second images acquired without any gap between them, so we directly observe eight minutes of cometary motion against the background stars. Yeah, it's moving pretty fast. http://cloudbait.com/gallery/comet/2...7_46P_anim.gif (Frame is 52.5 arcmin - nearly a degree- on each side.) |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Can't see the comet 46P/Wirtanen because it's like winter 1986 here | RichA[_6_] | Amateur Astronomy | 4 | December 14th 18 12:22 AM |
Would like to photograph the Perseids | Paul Ciszek | Amateur Astronomy | 1 | August 10th 12 11:26 PM |
Best Lunar Photograph I Have Ever Seen | Davoud[_1_] | Amateur Astronomy | 27 | December 3rd 08 05:47 PM |
Interesting photograph. | Thomas Lee Elifritz | Policy | 2 | March 15th 04 06:27 AM |
Interesting photograph. | jacob navia | Astronomy Misc | 4 | March 15th 04 06:27 AM |