Occultation by Pluto and maybe by P2, Australia, NZ, & Reunion, June 12
The 15th-mag. star will be hard to observe near a full moon
New: 2006 April 6
On 2006 June 12 around 16:25 UT, Pluto will occult 15.0-mag. UCAC2 26039859 at J2000 R.A. 17h 41m 12.08s, Dec. -15 deg. 41' 34.6". The event is in the IOTA local circumstance/appulse predictions so observers in Australia, New Zealand, and the southern Indian Ocean islands can see the circumstances there. The path for the occultation by Pluto passes over New Zealand, southeastern Australia, the far southern Indian Ocean, and southeastern Africa (but too low for effective observation there), according to the latest prediction by Bruno Sicardy. The small satellite P2 is predicted to occult the star along a more northerly path passing over southern Queensland, near the South Australia/Northern Territory border, central Western Australia, Reunion Island, Madagascar, and northern Mozambique. A central occultation by Pluto would last 97 seconds with a calculated 1.2-mag. drop, but I think that calculation is wrong. Bruno Sicardy writes about this event, and another in a few days in Chile (not in the IOTA predictions, must be a fainter star accessible only with large telescopes): ______________ From: Bruno SICARDY [sicardy@despace.obspm.fr] Sent: Wednesday, April 05, 2006 1:09 AM To: Dunham, David Subject: Pluto Ring Constraints, and satellites Dear Alan (I think addressed to Alan Stern before sent to me), Thanks for your mail. Actually, we try our best to observe stellar occultations, or appulses, by Pluto. These efforts combine professionals teams/telescopes, and amateurs, in particular the International Occultation and Timing Association (IOTA) - European Section. They might need some help and support for some of the events we want to observe. On the short term, we will observe - on 10 April 2006 - an appulse of a star with Pluto (ES0/Chile). We will use the star to scan the new satellites orbits, searching for possible debris around the planet. Another event, on 12 June 2006, is interesting because - beyond Pluto's atmosphere detection- it might yield an occultation by P2, see this map. The grey band is Pluto's shadow, and the line above is P2's shadow track. Red star symbols are possible observing stations. Shadow motion is from right to left. Dots are separated by 1 min. P2's shadow should sweep Australia and Indian Ocean. Typical errors (combination of star position and error on P2 ephem.) should be < +/- 1000 km. Independent checks on P2 ephemeris should be made. I have been alerting amateurs in Australia and La Reunion to see what can be done. With P2's diameter of ~ 50-100 km, a star fainter than Pluto in the visible range, and the full Moon at 14 deg, this is not an easy job... But anyway, it would be great to get P2's size! Cheers, Bruno ______________________ David Dunham, IOTA e-mail: home, dunham@starpower.net office, david.dunham@jhuapl.edu phones cell 301-526-5590; office 240-228-5609; home 301-474-4722