Sounds Exciting-Asteroid Occultations

[Ursa Major]

Hello,

I was wandering if anyone had seen any asteroid occulations? They seem like they might be quite exiting; you never really think about other objects out there apart from planets and moons and to and to witness the presence of these elusive objects would be amazing.

What am I likely to expect from an occulation of this type?

I have found this website http://mpocc.astro.cz/2011/a11_01058.gif as an example of an occualtion and I am guessing that on the map, the area inbetween the faint lines are where it can be view from. Am I right?

Thank you

[lukebl]

They're fairly frequent but I've never managed to catch one myself as the belt from where they are visible is very narrow. You can check them out at Calsky

I am planning to try and observe one on 14th June, when 17th magnitude asteroid Tamashina occults a 10th magnitude star in Sepens for 2-3 seconds. The central ine for that occultation runs roughly from Norwich to Aberystwyth and is about 20 miles wide.

[Ursa Major]

They're fairly frequent but I've never managed to catch one myself as the belt from where they are visible is very narrow. You can check them out at Calsky

I am planning to try and observe one on 14th June, when 17th magnitude asteroid Tamashina occults a 10th magnitude star in Sepens for 2-3 seconds. The central ine for that occultation runs roughly from Norwich to Aberystwyth and is about 20 miles wide.

Thanks Luke, looks like a very useful website. It’s interesting that it lasts 2-3 secs. I suppose you could probably calculate the size and shape of the asteroid if you were observing all along the 20 miles by recording the time period when the star disappears. This is where amateur astronomers can play an important role:headbang:

[Phil Fargaze]

You are quite right about being able to work out the size of an asteroid from observations. See here http://www.euraster.net/results/2011/20110401-Peraga-crd_temp.gif

I find this branch of astronomy very exciting and hope to observe a positive event one day soon, complete with video of the event too! I have managed to submit a succesful negative event so far. The area between the lines is the predicted path. Then there is usually dotted lines to indicate the error margin. So it is worth attempting an observation even if you are slightly outside the predicted path.

[Phil Fargaze]

Also, good luck lukebl for the Tamashina event. I am just about in the error line so I might try it.

[Ursa Major]

You are quite right about being able to work out the size of an asteroid from observations. See here http://www.euraster.net/results/2011/20110401-Peraga-crd_temp.gif

I find this branch of astronomy very exciting and hope to observe a positive event one day soon, complete with video of the event too! I have managed to submit a succesful negative event so far. The area between the lines is the predicted path. Then there is usually dotted lines to indicate the error margin. So it is worth attempting an observation even if you are slightly outside the predicted path.

There is one going through Devon tomorrow I think and I am just outside the predicted area, so if the skies are clear I’ll give it a shot.

Anyway, thanks for clearing that one up Phil.

[Phil Fargaze]

Every occultation has it`s own challenge and the fine details need to be checked. I noticed the Sidonia event through Devon is well placed but the target star is at mag +11 and at 18:23 UT the sky will be quite bright. So that one could be a bit tricky!

The moon provides a good taster of occultations and I managed to video this one. See here

YouTube - V1116 Tauri_0001.wmv

[Ursa Major]

Every occultation has it`s own challenge and the fine details need to be checked. I noticed the Sidonia event through Devon is well placed but the target star is at mag +11 and at 18:23 UT the sky will be quite bright. So that one could be a bit tricky!

The moon provides a good taster of occultations and I managed to video this one. See here

YouTube - V1116 Tauri_0001.wmv

Thanks, I think I would straggle to see a mag 11 star even in the best of conditions let alone 18:23 lol.

That’s a very nice video. Ive only observed 1 or 2 lunar occulations and on the first I remember being quite surprised (I don’t know why) at how fast the star disappears. I makes sense if you think about it but watching it through on stellarium it took ages to happen because the stars are scaled up to increase the screen brightness.

[Phil Fargaze]

Watching a disappearance always fills me with wonder. To me it`s a demonstration of the dynamics of the universe and it`s awesome power and speed of objects within it, which is not always obvious at a casual glance. If you do a search, you should find a number of videos of asteroid occultations on youtube, which are even more mysterious than the moon occulting a star.

[nicnac]

you want asteroids? it is said 2029 will be a good show.

last months S'N has an article in it that states "Apophis" is going to pass very close to us

[TimH]

Its a fantistic subject - can get enough.

I have recorded two positive this year (106) Dione duration 21s, and (46) Isis duration 1.8s, all from Berkshire (Four last year). The later had a path shift of 50km. Integrating Video and a GPS time inserter is the best set up. I record on digital tape.

If you do observe please please report your observations ! - positive or negative. Example form here Report form

I update this page Asteroid occultation tracks UK 2011

Good luck with (313) Chaldaea and (4186) Tamashima I will be out there. If you send reports to me, I can pass them on to EAON

I dont often log in. Please use the email address on the MAS link above.

Cheers, Tim Haymes

Asteroid Occultation Junkie in the UK

[Phil Fargaze]

TimH, the subject fascinates me too, I want to mostly dedicate my observing to asteroid occultations from now. Thanks for the link to your web page, it is very good. I have it on my desk top now. I hope to be able to rely on you in the future to help me submit my first positive event! Actually, I am going to order a GPS time inserter today.

[TimH]

Phil,

You wont regret the GPS time inserter. Please ask any questions and will do my best. Good luck with your observations from Hornchurch. Hopefully you wont need a 16". The 120N+ is great camera. I use it at 0.16 or 0.32 s integrations on a 12" Tim

[Phil Fargaze]

Thanks Tim, I have been searching for more guidance on getting the best from my camera and your reassurance on the GPS time inserter is comforting. I hope to be able to use my new Celestron C9.25 for observations, being more portable. Otherwise I have my 250mm F4.7 reflector which I am able to mount on the HEQ5.

Also, thanks to Ursa Major for starting the thread, it has been very interesting.