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View Full Version here: : Asteroid (1493)Sigrid occultation of TYC 6849-01006-1


middy
20-07-2021, 08:56 PM
Yesterday, after reading the 'Occultation observations of C/2014 UN271 Bernardinelli-Bernstein' thread over on the Astronomy and Amateur Science section my interest was piqued. So, after a few mouse clicks on Google I was down the rabbit hole of Asteroid Occultations. After installing the OccultWatcher app I found that an occultation was happening that evening from my location giving me 6 hours lead time. "No worries, I'll give it a crack", I thought.

Equipment:
8" F6 Newt with the ZWO ASI290MC camera.

I didn't have enough time to research best exposure times etc., so I just went with 350ms exposures with a Gain of 550.


So without further ado, here is the link to my capture of asteroid (1493)Sigrid occulting the star TYC 6849-01006-1. The video shows the event. Watch the stars near the centre for the one being occulted. The JPG is a stack of all the images taken. I ended up with 1440 images over a 6 minute period so why not stack them to see how many stars appear with 1440 x 350 ms exposures. Quite a few apparently.

https://1drv.ms/u/s!AkelT5umKabLhLAWjFHXfzm9jWdtDw?e= wOO7zJ

Now that I have had time to do a bit more research, next time I'll shoot video instead of individual images and I'll aim for 10 fps if possible. SharpCap can insert the timestamp into the video, so I may even be able to get some useful data next time.

tonybarry
20-07-2021, 09:24 PM
Howdy Andrew,

Good to hear you like the occultation work - I find it quite enjoyable.

You might wish to correspond your local occultation crew who are on the same events - which Occultwatcher will advise you of.

The International Occultation Timing Association just competed its yearly (zoom) meeting this weekend with around 80 attendees from all over the world. A number of Australians offered presentations to the meeting on various aspects of occultation observing and timing.

Best wishes for the avocation !

Regards,
Tony Barry
WSAAG
Penrith, Sydney

AstroJunk
20-07-2021, 09:35 PM
Yay! It was a miss for me. I'll give you a PM, if you want to continue your awesome start to occultation work, we really need to talk!

Tinderboxsky
21-07-2021, 10:14 AM
Fabulous result Andrew, especially going from zero to a successful result in six hours.

middy
21-07-2021, 11:43 PM
Thanks. I decided to run the data through the light curve analysis tool, Tangra, even though I don't have super accurate timing data. Yep, it definitely disappears and comes back again. :lol:

Keeping in mind that the only timing I had was the file creation time of each image, so only accurate to the nearest second.

Predicted:
Event Time: 21:32:54 (+/- 7 secs)
Max Duration: 4.9 secs

Observed:
Event Time: 21:32:53
Max Duration: 4.2 secs

I'll call it a win. :thumbsup:

AstroJunk
22-07-2021, 08:22 AM
https://www.timesynctool.com/

I use net time, just before I start the event to sync the clock. I did extensive testing along side a gps time insertion tool and found that it was accurate to +/- 5ms or better every time. The developer claims a conservative 10-100 ms which is still very good, I guess it may depend on your internet latency - the lower the better.

Your windows clock most likely keeps the machine updated to within a second if the time service is switched on, it's not a bad idea to switch it off if you decide, like me, to use third party software.

38degsouth
27-07-2021, 09:51 PM
Nice catch! Welcome to the caper of catching shadows :thumbsup:

multiweb
20-08-2021, 10:14 PM
Very cool. :thumbsup: