Celestia Forums

I am a member of the Westchester Amateur Astronomers,a club located in New York state,USA(~41N 73W)..Our website has informed us of an asteroidal occultation, of the star 16 Piscium by the asteroid Iris that should be viewable in our area.This brought to mind a question:how might I use Celestia to simulate such an occultation?Can it be done?I've been browsing this forum for awhile and I don't recall seeing a discussion of this.if someone else has done work in this area I'd love to hear about it .I'd like to create a simulation of this particular occultation,but any ideas pertinent to this kind of situation would be most welcome.Thanks.

When will this happen? Time est? Date? Did you try to goto the surface of earth for your coordinates. Then center the star. Go forward in time to the event? And see how accurate celestia IS?

cartrite

I just did a quick visit to your site and:

A list of stations listed by distance in kilometers from the central line can be found at Derek Breit's Web site. The occultation will occur within half a minute of 5:02 am EDT (9:02.0 UT) for all locations.

The star 16 Piscium is located at R.A. 23h 36m 23.2s, Dec. +02 deg. 06' 08" (J2000), in the "Circlet" of Pisces. The asteroid is estimated to be 200-km in diameter.

At the time of occultation, 16 Piscium will be 16 degrees above the eastern horizon as seen from our location. The Sun will be 8 degrees below the horiozn, so twilight will start to interfere. If an occultation occurs, there will be a 4.4-magnitude drop in the stars brightness lasting about five seconds for observers on the central line. The observations might reveal the star to be a close double, in which case, the disappearance and/or reappearance will occur in steps.

I would like to try this but my computer just succumbed after a long illness. What I'm left with is an old P1 200mhz which I'm not going to try to get celestia running on. Internet access is all I got for now.

cartrite

Here are the particulars(from website waa.org):
"The best asteroidal occultation ever predicted for the northeastern USA, and potentially the best in the USA since 1983, will occur Friday Morning, May 5, when 5.8-magnitude 16 Piscium is occulted by asteroid (7) Iris.

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The occultation will occur within half a minute of 5:02 am EDT (9:02.0 UT) for all locations.

The star 16 Piscium is located at R.A. 23h 36m 23.2s, Dec. +02 deg. 06' 08" (J2000), in the "Circlet" of Pisces. The asteroid is estimated to be 200-km in diameter.

At the time of occultation, 16 Piscium will be 16 degrees above the eastern horizon as seen from our location. The Sun will be 8 degrees below the horiozn, so twilight will start to interfere. If an occultation occurs, there will be a 4.4-magnitude drop in the stars brightness lasting about five seconds for observers on the central line. The observations might reveal the star to be a close double, in which case, the disappearance and/or reappearance will occur in steps.

White Plains is 56 kilometers south of the asteroid path with a 100% probability of seeing the occultation at 5:02 a.m. Advanced astronomers can record the occultation on video along with a time signal from WWV and submit the tape to IOTA."

Hello cartrite. after going back to my club's site to get the info ,I see you beat me to the punch.But i'm still not sure about how to go about simulating this event in celestia.I think I know how to goto the coordinates of my observing location and "look back" to get a sky view,and I know how to locate the desired star.but how do I get the asteroids info into the picture?

If You zoom in or change your field of veiw the asteroid should be close at the time of the event. If it is, click on it to display. I'm not sure if that asteroid is in the Celestia solarsystem. Did you try entering the asteroid into the command line? If it's not there you would have to enter it's details in the one of the data files in the DATA folder(not sure which one though). I would NOT edit that file though. I would copy the data to a new file. Take a look at Selden's addon template. Without the Celestia folders I am just going on memory and I don't want to stear you wrong. Mabey someone else out there?

cartrite

Unfortunately, a catalog entry for (7) Iris is not included with Celestia. You need to get its most recent osculating elements and create a .SSC catalog for it. Current elements should be available either from Horizons or the Minor Planets Center.

[edit]
http://www.lepp.cornell.edu/~seb/celest ... meris.html
explains how to translate into Celestia's format.
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