Asteroid Xanthippe occultation, 29th October 2018

[lukebl]

I was very pleased to capture my first ever asteroid occultation this evening. Asteroid (156) Xanthippe occulted a 12th magnitude star in Aquila, and I finally got to use my new Runcam camera properly (Thanks @furrysocks2). It's basically just a relatively cheap drone cam, but very sensitive and is suggested as being useful for occultation measurements. My initial review of it is HERE.

The camera operates at 25 fps, and can easily capture 12th magnitude stars even with such short exposures. The occultation was predicted to occur at 19:19:19, so I started to capture a video from about 19:19:00. The occultation actually occurred at about 19:19:14 (5 seconds early) and lasted just over three seconds at my location about 60 kilometres from the centre line. Here is the light curve produced by Tangra software, showing the clear dip in the light curve.

Runcam Night Eagle Astro, 200mm f/5 Newtonian, captured with Debut Professional, GPS Timestamped with GPSBOXSPRITE3. I think it proved its worth this evening.

Perhaps someone can direct me to where I should submit my record.

 

[Helen]

Brilliantly done!!  (I failed miserably!)

You could submit to the BAA - details here https://britastro.org/node/16174

Helen

 

[Phil Fargaze]

I got a positive result for this one as well, provisional time 5.7 seconds at 6.2 km from predicted center line. If you follow the link Helen provided and contact Tim Haymes he will make sure your data gets sent to the European coordinator and provide any advice. I was aware of around 30 observers across Europe prepared to observe this event. So far there have been about five confirmed positives from the UK. Some observers have also reported being clouded out. 

[tooth_dr]

Amazing!

[David Levi]

Hi Luke @lukebl. I tried to look at this visually last night and failed, of course, with my Sky-Watcher 200P reflector. I've just read your report on this camera and it is very interesting. I have a question, I hope it's not a daft one. Do you use this camera with a tracking mount or is the exposure so quick that it doesn't matter?

[lukebl]

1 hour ago, David Levi said:

........Do you use this camera with a tracking mount or is the exposure so quick that it doesn't matter?

Yes, this was captured using a tracking equatorial mount. The field of view with the camera's tiny sensor is very narrow, and you need to capture a video with a length of a minute or so to be sure of capturing the event. This wouldn't really be possible with an undriven mount. The 'drift-scan' technique (do a search for that on the web) is another way of doing it without tracking, although I haven't tried it myself. 

[Phil Fargaze]

Some results have already been published by Eric Frappa which you will find on the Eurastar web site here. It shows the timings submitted from individual locations to build up a picture of the shape and size of the asteroid.

https://www.euraster.net/results/2018/index.html#1029-156

https://www.euraster.net/results/2018/20181029-Xanthippe_crd.gif

My chord at the moment is number six. It’s reassuring to see my results correlate well with the other observations. As more observations get submitted the results should get updated. 

 

 

[lukebl]

Here are the current results. Mine is number 1