 The northern
limit, centerline, and southern limit of Pluto's shadow are shown by the
three lines across the globe pictured above. The shaded area represents
where the sun is more than 12 degrees below the horizon. |
P495.3 Prediction (as of: 2007 03 21) |
| Geocentric Mid-time (yyyy month dd hh:mm:ss) | 2007 July 31 13:50:11± 00:00:11 UT |
| Minimum Geocentric Separation | 0.271± 0.008 arcsec |
| Position Angle (Pluto relative to the star; measured north through east) | 167.921 degrees |
| Geocentric Velocity | 16.8 km/sec |
| Prediction Version | P495.3-AST-1.4 |
| Reference star position: (UCAC2, at epoch of event) |
RA (h:m:s; J2000) | Dec (d:m:s; J2000) | UCAC Mag1 |
| P495.3 | 17 45 41.9795 | –16 29 31.654 | 13.3 |
| P495.3 Corrected | 17 45 41.9845 | –16 29 31.667 | |
| 1The
UCAC bandpass (579-642nm) is between V and R. |
|||
| Offsets
from Reference Position/Ephemeris2 |
|||
| Body | RA (arcsec) | Dec (arcsec) | Notes |
P495.3 |
+0.078± 0.008 | –0.012± 0.008 | From 60 strip scans |
| Pluto | ------- |
------- | |
| 2All
"offsets" are defined in the ("corrected" –
"reference") or ("observed" – "calculated")
sense. The offsets should be added to reference positions to get the measured
positions, which we use to calculate the prediction. |
|||
Discussion
On July 31st, 2007, Pluto will occult P495.3 (= 2UCAC 25815762; as originally published in McDonald & Elliot, 2000; Table). The above map and the following prediction results are from the analysis of 60 strip scans obtained at the Lowell Observatory Astrograph by Rosemary Pike and Amanda Bosh during 2005-2007.
Proper motion of the star has been applied up to the time of the occultation (according to the UCAC2 catalog, dRA: –10.8± 7.9 mas/yr, dDec: –3.3± 7.9 mas/yr). The offsets between the measured RA and Dec of P495.3 and its UCAC2 values at the time of the event are also given in the table.
Prediction Notes
Archive of all P495.3 occultation predictions based on alternate sources of data, including past predictions
P495.3 Occultation Predictions for Individual Sites
| Site | East Longitude | Latitude | Distance (km)3 | Pluto Immersion (UT)4 |
Mid-Time (UT)4 |
Pluto Emersion (UT)4 |
Altitude at Midtime (deg)
|
Velocity (km/s) |
| Hobart | 147 26 24 | –42 48 18 | 2363 N. | ---------- | 13:48:07 | ---------- | 49.1 | 17.02 |
| Mt. John | 170 27 50 | –43 59 22 | 1636 N. | ---------- | 13:47:05 | ---------- | 33.1 | 16.92 |
| Mt. Stromlo | 149 00 35 | –35 18 57 | 2974 N. | ---------- | 13:47:34 | ---------- | 51.1 | 17.04 |
| Siding Spring | 149 03 44 | –31 16 17 | 3348 N. | ---------- | 13:47:20 | ---------- | 52.3 | 17.06 |
| Black Spring | 138 53 18 | –33 53 58 | 3405 N. | ---------- | 13:48:12 | ---------- | 59.2 | 17.09 |
| Geocentric | ---------- | --------- | 5953 N. | ---------- | 13:50:11 | ---------- | ---------- | 16.76 |
3"Distance" refers to the closest approach distance of the "Site" to the center of Pluto's shadow in the shadow plane. The errors on all closest approach distances are 187 km (one standard deviation). "N." means the site is North of the center of Pluto's shadow.
4The errors on all times are ±00:00:11 (11 seconds; one standard deviation)
Results of Previous Occultations
Results of the 2006 Pluto occultation are described and compared with results of the 1988 and 2002 occultation in a preprint, Changes in Pluto's Atmosphere: 1988-2006
Last updated by Carlos A Zuluaga (czuluaga@mit.edu) 2007-03-21 02:45
Please direct all inquiries to Planetary Astronomy Lab (planetary-astronomy@mit.edu)
