Pluto Occultation March 18, 2007

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.

P445.3 Prediction

(as of: 2007 04 04)

Geocentric Mid-time (yyyy month dd hh:mm:ss) 2007 March 18 10:56:41± 00:01:25 UT
Minimum Geocentric Separation 0.264± 0.025 arcsec
Position Angle (Pluto relative to the star; measured north through east) –15.99 degrees
Geocentric Velocity 7.1 km/sec
Prediction Version P445.3-AST-1.9

 

Star position:
(at epoch of event)
RA (h:m:s; J2000) Dec (d:m:s; J2000) UCAC Mag1
P445.3 (Reference; UCAC2) 17 55 05.6921 –16 28 34.4573 15.3
P445.3 (Measured) 17 55 05.6941 –16 28 34.3425  
1The UCAC bandpass (579-642nm) is between V and R.
Offsets from Reference Position/Ephemeris2
Body RA (arcsec) Dec (arcsec) Notes

P445.3

+0.029± 0.017 +0.115± 0.015 From 33 strip scans
Pluto –0.047± 0.019 +0.084± 0.020 From 34 strip scans
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

Archive of all P445.3 occultation predictions based on alternate sources of data, including past predictions

 

Site Information*

Site
East Longitude
Latitude

Altitude3

(km)

Distance4

(km)

Velocity

(km/s)

Flagstaff
–111 44 23
35 11 02
2.31
776 S.
6.78
Fremont Peak
–121 29 55
36 45 37
0.84
697 S.
6.83
JPL Table Mountain
–117 40 54
34 22 54
2.29
823 S.
6.80
Lick Obs.
–121 38 12
37 20 36
1.29
665 S.
6.83
Magdalena Ridge Obs.
–107 11 05
33 58 36
3.18
866 S.
6.76
Mt. Graham
–109 53 31
32 42 04
3.191
932 S.
6.78
Mt. Hopkins
–110 53 04
31 41 19
2.61
993 S.
6.77
Palomar
–116 51 54
33 21 24
1.71
885 S.
6.80
Geocentric
----------
---------
center of Earth
6276 S.
7.09

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 ±571 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.

Predicted Occultation and Orbit Crossing Times for Individual Sites*

Site
Hydra Imm Orbit Crossing Time (UT)5
Nix Imm Orbit Crossing Time (UT)5
Charon Imm Orbit Crossing (UT)5
Pluto Immersion (UT)5
Mid-Time (UT)5

Pluto Emersion (UT)5

Charon Em Orbit Crossing (UT)5

Nix Em Orbit Crossing Time (UT)5
Hydra Em Orbit Crossing Time (UT)5
Flagstaff
09:08:33
09:31:16
10:20:19
10:49:31
10:51:46 (24°)
10:54:01
11:24:20
12:10:02
12:45:23
Fremont Peak
09:08:05
09:29:25
10:19:16
10:48:07
10:50:30 (18°)
10:52:53
11:22:49
12:08:20
12:44:49
JPL Table Mountain
09:07:52
09:33:32
10:19:22
10:48:32
10:50:41 (21°)
10:52:49
11:23:08
12:08:44
12:44:43
Lick Obs.
09:08:12
09:30:23
10:19:22
10:48:09
10:50:35 (17°)
10:53:01
11:22:53
12:08:23
12:44:29
Magdalena Ridge Obs.
09:08:47
09:31:20
10:20:50
10:50:21
10:52:24 (28°)
10:54:27
11:25:06
12:10:51
12:45:35
Mt. Graham
09:08:15
09:32:01
10:20:12
10:49:52
10:51:44 (25°)
10:53:35
11:24:25
12:10:08
12:44:41
Mt. Hopkins
09:07:57
09:31:06
10:19:53
10:49:45
10:51:25 (28°)
10:53:04
11:24:05
12:10:03
12:43:22
Palomar
09:07:43
09:32:25
10:19:16
10:48:40
10:50:39 (23°)
10:52:38
11:23:09
12:08:46
12:42:35
Geocentric
09:16:15
09:31:07
10:27:14
----------
10:56:41
----------
11:26:18
12:09:49
12:37:04

5The errors on all times are ±1:25 (1 minute and 25 seconds; one standard deviation). In parenthesis is the elevation of the body above the celestial horizon in degrees.

 

* Based on the analysis of the astrometric data, not on the analysis of the occultation light curves.

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


Please direct all inquiries to Planetary Astronomy Lab (planetary-astronomy@mit.edu)

Last updated by Carlos A Zuluaga (czuluaga@mit.edu) 2007-04-04 9:40