 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. |
P468 Prediction (as of: 2007 05 25) |
| Geocentric Mid-time (yyyy month dd hh:mm:ss) | 2007 June 14 01:27:43± 00:00:17 UT |
| Minimum Geocentric Separation | 0.003± 0.019 arcsec |
| Position Angle (Pluto relative to the star; measured north through east) | -2.05 degrees |
| Geocentric Velocity | 23.6 km/sec |
| Prediction Version | P468-AST-1.5 |
| Reference star position: (UCAC2, at epoch of event) |
RA (h:m:s; J2000) | Dec (d:m:s; J2000) | UCAC Mag1 |
| P468 | 17 50 20.7407 | –16 22 42.134 | 15.9 |
| P468 Corrected | 17 50 20.7367 | –16 22 42.250 | |
| 1The
UCAC bandpass (579-642nm) is between V and R. |
|||
| Offsets
from Reference Position/Ephemeris2 |
|||
| Body | RA (arcsec) | Dec (arcsec) | Notes |
P468 |
–0.0595± 0.0141 | –0.116± 0.013 | From 30 strip scans |
| Pluto | –0.0549± 0.0123 | +0.039± 0.014 | 207 strip scans and 89 USNO-61inch Telescope frames |
| 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 June 14th, 2007, Pluto will occult P468 (= 2UCAC 25819301; as originally published in McDonald & Elliot 2000a, 2000b; Table). The above map and the following prediction results are from the analysis of 207 strip scans obtained at the Lowell Observatory Astrograph by Rosemary Pike and Amanda Bosh during 2005-2007 (the strip scans from earlier years did not contain Pluto-Charon images) and 89 frames taken on 2005 and 2007 by Steve Levine with the 1.55-m Kaj Strand Astrometric Reflector.
Proper motion of the star has been applied up to the time of the occultation (according to the UCAC2 catalog, dRA: –6.6± 8.0 mas/yr, dDec: –6.4 ± 8.1 mas/yr). The offsets between the measured RA and Dec of P468 and its UCAC2 values at the time of the event are also given in the table.
Prediction Notes
Archive of all P468 occultation predictions based on alternate sources of data, including past predictions
Site Information
Site |
East Longitude |
Latitude |
Altitude3 (km) |
Distance4 (km) |
Velocity (km/s) |
Boyden Obs. |
26 23 48 |
–29 02 30 |
1.4 |
2003 S. |
23.94 |
Cerro Armazones |
–70 11 47 |
–24 35 51 |
0.5 |
1466 S. |
23.86 |
Las Campanas |
–70 42 00 |
–29 00 30 |
2.3 |
1939 S. |
23.85 |
Pico dos Dias |
–45 34 57 |
–22 32 04 |
1.9 |
856 S. |
24.00 |
SAAO |
20 48 36 |
–32 22 54 |
1.8 |
2236 S. |
23.96 |
Geocentric |
---------- |
--------- |
--------- |
84 N. |
23.63 |
3Altitude of each observatory is measured in kilometers above sea level.
4"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 ±474 km (one standard deviation). "S." means the site is South of the center of Pluto's shadow. "N." means the site is North of the center of Pluto's shadow.
P468 Occultation Predictions for Individual Sites
Site |
Pluto Immersion (UT)5 |
Mid-Time (UT)5 |
Pluto Emersion (UT)5 |
Boyden Obs. |
-------- |
01:25:07 (50°) |
-------- |
Cerro Armazones |
-------- |
01:31:01 (40°) |
-------- |
Las Campanas |
-------- |
01:30:56 (41°) |
-------- |
Pico dos Dias |
01:29:08 |
01:29:44 (63°) |
01:30:19 |
SAAO |
-------- |
01:25:29 (54°) |
-------- |
Geocentric |
01:26:51 |
01:27:42 |
01:28:33 |
5The errors on all times are ±00:00:17 (17 seconds; one standard deviation). In parenthesis is the elevation of the body above the celestial horizon in degrees.
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) 2007-05-25 11:35
Please direct all inquiries to Planetary Astronomy Lab (planetary-astronomy@mit.edu)