International Occultation Timing Association

European Section 

2010 July 08

Asteroid (472) Roma occults 2.7 mag star delta Oph

New predicted track!

There will be an extraordinary event on the late evening of July 8^th 2010. Asteroid (472) Roma (13.5 mag) will occult the 2.7 mag star delta Oph at the constellation Ophiuchus.

The asteroid will occult the star around 21:57 U.T. over Europe. The expected maximum duration of occultation is 5.6 seconds.

The combined magnitude of star and asteroid will be dropping down by 10.8 mag to 13.5 mag.

This event can be observed even with small instruments. Please measure this occultation and you will be part of a European wide scientific observation.

Because of the brightness of the event and the path across Europe there is a chance to add the observation of (472) Roma to the best observed asteroidal occulations in the history of astronomy.

The "All time best observed" up to now:

(Source: Software „Occult 4“ by Dave Herald, Version Mai 2010)

The shadow of the asteroid crosses Finland, Sweden, Northern Germany, Belgium, Luxembourg, France, Spain, Portugal, and the Canary Islands.

PLEASE DON’T TRUST THE GIVEN PROBABILITIES!

Steve Preston wrote at May 18:

“The star is included in both the FK6 and HIP2 (second reduction of Hipparcos) catalogs. Unfortunately, the proper motions from these two catalogs are not consistent and there are good arguments for preferring either FK6 or HIP2. In addition, this star is part of a multiple star system and there are implications that the target star may actually be a close double star. Although, two attempts with interferometer instruments have not found a companion. I have chosen to use the FK6 data for the path prediction currently posted on asteroidoccultation.com. The HIP2 position would be about ½ pathwidth SE of the posted (FK6) path.

Given the issues with the star, I recommend that observing groups spread out to at least 2 sigma from the predicted path. And, there may be good reason to place more observers on the SE side of the predicted path.”

Steve Preston uses weighted data from both catalogues (HIP2 and FK6) for his prediction update.

PLEASE OBSERVE EVEN AT THE 2-SIGMA LIMITS!

If you want to show the path at Google Earth use the following file: (kml Datei).

Please visit Steve Preston’s web page for the complete data of his update.

Please send your report to IOTA-ES after your observing session..

• Observation report

Please use this e-mail address for your report, questions and suggestions:roma2010(at)iota-es.de

Good luck and clear skies!

Oliver Klös
IOTA-ES

Occultation Tracks

Germany

Europe - North

Europe - South