Astronomy, Photography and Weather

General Category => Weather & Atmospherics => Topic started by: brianb on August 29, 2009, 04:23:25 pm



Title: How to image the wind?
Post by: brianb on August 29, 2009, 04:23:25 pm
A good question ... here's my attempt. Last night I was trying to take some images for photometry in the field of V Vul, but the wind (much stronger than forecast) wasn't helping at all; despite a solid tripod, many images were affected by wind vibration.

Here's an exceptionally good example; note the satellite track....
(http://www.bbhvig.uklinux.net/IMG_1501_G.jpg)


Title: Re: How to image the wind?
Post by: martinastro on August 29, 2009, 04:27:18 pm
That's a cool image Brian, the wind produced a nice corkscrew pattern in that sat trail. There has indeed been some gusty winds around lately, shows how dedicated you are anyway!  :)


Title: Re: How to image the wind?
Post by: rjgjr on August 29, 2009, 07:52:50 pm
Definitly an interesting sat trail. Must have been an exceptionally strong wind to cause that much vibration in your tripod and mount!


Title: Re: How to image the wind?
Post by: brianb on August 29, 2009, 09:25:03 pm
Quote
Must have been an exceptionally strong wind to cause that much vibration in your tripod and mount!
About force 6 with gusts to gale force.... "Exceptionally strong" here would be storm force but I'd not normally be out in such conditions.

Incidentally I did get useful data from the session - had to reject 7 out of 21 frames of this set due to excessive vibration and the residuals from the remaining frames were larger than usual (0.04 - 0.05 mags instead of 0.01 - 0.02); using two different comparison stars I found V Vul at 8.757 +/- 0.045 and 8.741 +/- 0.050 (V band) on 2009 August 29.02. The sets on epsilon Aurigae, gamma Cassiopeiae and rho Cassiopeiae were much more successful due to the shorter focal length employed for measuring bright objects.

Is anyone else following epsilon Aurigae?