Can anybody help me??

[steveangel]

Hi all,

Im currently embarking on my final year project for my physics degree and wanted to do something astro based.

With the help of my supervisor I've decided to study 'lunar occultations of stars' and use the diffraction patterns to determine the stella diameters.

However, I am struggling to find dates and times of events visable from my location (Southampton, UK) and my supervisor has refused to help me find my targets.

The Society for Popular Astronomy website says it welcomes emails from people interested in observing these events (since they only list events involving stars no fainter than mag 6), however they are yet to get back to me.

If anyone on here has any helpful information I will be eternally grateful,

Steve

Edit: I will be using either an 8, 10 or 12" Meade SC depending on the availability, so much fainter stars will be visible than those listed on SPA

[barkis]

Hi. Steve.

I'm no astro phycisist, but I've read something on this, and it is that you can measure a stars angular diameter, but it's absolute diameter will require knowing its distance.

Would that not inhibit the number of candidates you might have at your disposal, assuming you are wishing to determine star diameters.

I wish I could help regarding occultations for 2012, but a Google search might turn up a downloadable almanac that may assist you.

Best of luck with your project, it's a challenging one.

Pity you haven't the time to use eclipsing binaries .

Ron.

[Cjg]

Hi Steve,

A quick search revealed IOTA Main Table of Contents

They have a table on the page I have listed with forthcoming events, as well as links to other sites.

Good luck

Chris

[Astro Imp]

By doing a Google search I found reference to Astronomical Tables by Jean Meeus published by Willman-Bell the latest edition of which lists occultations to 2020.

BTW I found this information Here

HTH.

[Freddie]

Have a look on the web for the IOTA (International Occultation Timing Association).

[steveangel]

Hi Ron,

You're right about it giving the angular diameter (through timing how quickly it disappears behind the moon), but its by studying the diffraction pattern (as the Moon's limb begins to pass in front of the star's disk, it diffracts the light from the star in the same way light is diffracted when it passes through a narrow slit) that we can determine the diameter.

Its funny you should mention eclipsing binaries though because that was on the shortlist of projects. Do you have much info on them, as Im sure I could split the focus of the project as it seems the occultations will be few and far between

Steve

[steveangel]

Sorry, only just realised there were other replies, clearly took too long writing mine lol

Chris / Freddie - Thanks for the suggestion but unfortunetly the events listed on their page can't be seen from the UK

Alan - that is exactly what Im looking for, however accessing the data within is easier said than done. Cant seem to find either a hardcopy or digital version :S

Thanks for responding so quickly though

Steve

[barkis]

Hi Ron,

You're right about it giving the angular diameter (through timing how quickly it disappears behind the moon), but its by studying the diffraction pattern (as the Moon's limb begins to pass in front of the star's disk, it diffracts the light from the star in the same way light is diffracted when it passes through a narrow slit) that we can determine the diameter.

Its funny you should mention eclipsing binaries though because that was on the shortlist of projects. Do you have much info on them, as Im sure I could split the focus of the project as it seems the occultations will be few and far between

Steve

The bit I read on the subject, suggested that the moons irregular limb made a poor knife edge for such a task, due to its valleys and mountains. My personal knowlegde on the subject is very sparse, and I'm quoting from memory, a source I can't name, my memory is so bad.

Ron.

[callump]

The BAA annual Handbook lists occultations of 'bright' stars - it lists 3 in November and 7 in December (2011) - when will you be observing ?

The BAA Variable Star Section would be able to help on eclipsing binaries too - they have predictions on their website BAAVSS

Callum

[E621Keith]

The BAA handbook only listed occultation down to mag 6. As callump said the handbook listed 3 events in November and 7 in December, but only 4 in December occur during normal university access hours.

I ran Stallarium (location:Southampton), to get the stars and event time:

3/12 16:34 - 16 Psc

7/12 21:22 - 40 Ari

9/12 19:10 - HIP 20842

14/12 22:04 - Acubens

I'm also in soton, so PM me if you want to borrow the BAA handbook. The handbook listed event time in Greenwich, which is a few minutes ahead of Southampton. You'll need to apply correction to get the event time in soton.

Hope this help

[steveangel]

Thanks again for the help guys,

Ron - I can imagine it might cause a small problem but because the stars are essentially points of light I think the difference will be negligable, however its deffinetly something ill bring up with my supervisor

Callum/Keith - Because the events dont seem to happen that often I am going to try and get as many as possible, so if one of you could post the other event dates in Nov and Dec that would be awesome. I have access to the telescope 24/7 so only problem is when the Suns in the way.

Steve