There is a potential occultation of the star P495.3 by Pluto on 2007 July 31 UT. The star is bright, about 13.5 mag, making this the brightest occultation star since the Pluto atmosphere discovery in 1988.
Our group (PHOT = Portable High-speed occultation telescope) is deploying to five locations. Auckland, Auckland 0.4 m Grant Christie, Tim Natusch Mount John 1.0 m Leslie Young, Bob Howell (two cameras, w/ dichroic) AAT 4.0 m Cathy Olkin, Kevin Shoemaker Mt Canopus 1.0 m Eliot Young Launceston 0.35 m Jeff Regester, Trina Ruhland (portable 14-inch Meade)
Star Positions
Using the UCAC2 catalog position as our reference psotions, we find the following star positions:
Source RA Dec dra ddec errx erry ------------ -------------- ------------- ----- ------- ---- ---- UCAC2 17:45:41.9799 -16:29:31.652 0 0 62 62 2MASS 17:45:41.9900 -16:29:31.700 145 -48 60 60 UCAC2-2006 17:45:41.9865 -16:29:31.690 96 -38 5 11 Bruno (Rio) 17:45:41.9850 -16:29:31.647 73 5 P495.3-AST-1.5 17:45:41.9849 -16:29:31.665 72 -13 9 9 Lowell 31-in 17:45:41.9827 -16:29:31.728 41 -76 22 21 -------------------------------------------------------------------RA and Dec are epoch of date (where proper motion is know), equinox J2000.
Bruno (Rio) - from http://www.lesia.obspm.fr/~sicardy/31_jul_07/index.html
MIT prediction 1.5 above uses the value as of June 4, 2007. The value has since been updated. See Jim Elliot's group's prediction
Lowell 31-in are from fifteen nights on the 31 inch telescope at Lowell Observatory.
Pluto offsets
Using the DE-413 and PLU-013 ephemerides from JPL as our reference ephemerides, the following offsets are reported
Source dra ddec (milliarcsec) ------------ ----- ---- Lowell 31" -6.7 2.4 MIT 2007-07-12 -42.6 26.0 Bruno Sicardy -100.0 80.0 ------------ ----- ----
Globes
PHOT Prediction: pred102 posted on 20070629 at 13:48 MDT PHOT (Cathy Olkin)
event times
Predictions for 2007 July 31 Occultation of P495.3 by Pluto by Richard G. French, Wellesley College mimas.wellesley.edu:/Volumes/pandora_raid2/Research/PHOT/programs/P495.3_occpred_v4.pro Thu Jul 19 14:01:21 2007
BEGIN OBSERVING 5 MINUTES BEFORE EARLIEST IMMERSION AND CONTINUE UNTIL 5 MINUTES AFTER LATEST EMERSION
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P445.3 predictions for Mt. John
Distance
Closest 163 km
Farthest 1941 km
Immersion Midtime Emersion
Earliest 13:43:39 13:45:00 13:46:22
Latest 13:46:24 13:47:44 13:49:04
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P445.3 predictions for Auckland
Distance
Closest 71 km
Farthest 2355 km
Immersion Midtime Emersion
Earliest 13:42:57 13:44:18 13:45:39
Latest 13:45:51 13:47:01 13:48:11
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P445.3 predictions for Mt. Canopus
Distance
Closest 175 km
Farthest 2663 km
Immersion Midtime Emersion
Earliest 13:44:49 13:46:04 13:47:19
Latest 13:47:52 13:48:46 13:49:40
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P445.3 predictions for Launceston
Distance
Closest 304 km
Farthest 2792 km
Immersion Midtime Emersion
Earliest 13:44:46 13:45:59 13:47:10
Latest 13:47:57 13:48:41 13:49:25
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P445.3 predictions for AAT
Distance
Closest 59 km
Farthest 3654 km
Immersion Midtime Emersion
Earliest 13:44:38 13:45:16 13:46:08
Latest 13:47:02 13:47:58 13:47:41
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| | Star designation |RA (J2000) |Dec (J2000) | dra |ddec| mag |filter| | A |ucac2 25815762 |17:45:41.9856 |-16:29:31.627 | 0 | 0 | 13.2 | U2R | | B |USNO-B1.0 0735-0463618 |17:45:42.9100 |-16:29:41.300 | 13 | -10 | 15.2 | R2 | | C |USNO-B1.0 0735-0463569 |17:45:42.0900 |-16:29:44.100 | 2 | -12 | 15.2 | R2 | | D |ucac2 25815751 |17:45:40.9794 |-16:29:35.648 | -14 | -4 | 15.9 | U2R| | E |ucac2 25815721 |17:45:35.6675 |-16:29:44.204 | -91 | -13 | 14.8 | U2R| | F |ucac2 25815705 |17:45:34.0410 |-16:29:52.116 |-114 | -20 | 10.9 | U2R| | G |ucac2 25815689 |17:45:32.6810 |-16:29:37.314 |-134 | -6 | 13.6 | U2R| | H |ucac2 25815791 |17:45:46.0757 |-16:29:30.971 | 59 | 1 | 14.4 | U2R| | I |ucac2 25815665 |17:45:30.4834 |-16:28:59.006 |-165 | 33 | 10.9 | U2R| | | SAO 160807 |17:46:10.7500 |-16:35:28.000 | 414 |-356 | 8.4 | V | U2R = UCAC2 filter, midway between V and R R2 = the second R mag listed in the USNO B1.0 catalog V = V mag from the SAO catalog
Finder charts
