Pluto.20220731

July 31, 2022

Finder Charts

Observing Information

Prediction Last Updated: January 22, 2022

No description available

Across the globe pictured, the three solid black lines correspond to the northern limit, centerline, and southern limit of the Pluto's shadow. The Northern and Southern limits correspond to a radius of 1400 km. The dashed lines indicate 3-sigma errors. The shaded area on the globe represents where the sun is more than 0 degrees below the horizon. The shadow paths on the globe are an approximation at the geocentric close approach time; they disregard the Earth rotation during the event.



Table 1: Prediction Details
Pluto Geocentric Mid-time (hh:mm:ss)

July 31, 2022 17:35:04 ± 00:00:22. UT1

Prediction pred1.0_v1.0
Pluto apparent magnitude 14.3
Occultation Star Gaia DR2 G magnitude 17.01087
Occultation Star Gaia DR2 rp magnitude 16.206244
Occultation Star Gaia DR2 bp magnitude 17.682362
Pluto Minimum Geocentric Separation 0.2129 ± 0.0267 arcsec1
Position Angle (Pluto relative to the star; measured north through east) -14.54

1One standard deviation of random error




Table 2: Reference Star Position
Reference star position:
(Gaia DR2)
RA (h:m:s; J2000) Dec (d:m:s; J2000) Notes
Pluto.20220731 (Catalog; epoch of occ) 19:56:58.0706 ± 0.001 -22:54:40.7952 ± 0.0006
Pluto.20220731 (Measured) - -

Potential Star Duplicity:

Unknown




Table 3: Projected KBO Offsets from Reference Ephemeris at the Time of the Event
Body RA (arcsec) Dec (arcsec)  
Pluto

0.0679 ± 0.0210

0.0027 ± 0.0270 See Notes 5 and 6; Includes Pluto Center of Light to Center of Body correction

2Measured position corresponds to RA offset of 0. and Dec. offset of 0.

3All "offsets" are degined 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.

4The reference positions for Pluto are those given by JPL Horizon's ephemeris (Pluto source file: plu55l_merged ; Earth center source file: plu55l_merged)

5Data from various telescope were reduced with respect to the Gaia DR2 catalog. A model was developed to fit the residuals obtained from our measured positions compared to that of the object's JPL ephemeris. All residuals obtained from the different telescopes were consistent with the model. The model includes the first-order effects of errors in the orbital elements of the object: (i) constant offsets in RA and Dec, (ii) linear (in time) offsets in RA and Dec, and (iii) potential sinusoidal terms with companion's period. The model was propagated to obtain the predicted position and error of the KBO at the time of the occultation. The errors listed for the KBO are 1 standard deviation.




Table 4: Site Information
Site
East Longitude
Latitude

Site Altitude6

(km)

Distance7

(km)

Velocity

(km/s)

Bangkok
100 30 06
13 45 22
0.
1943 S
24.13
Beijing
116 24 26
39 54 15
0.
550 S
24.00
Hong Kong
114 10 09
22 19 09
0.
1736 S
24.07
Mumbai
72 52 39
19 04 33
0.
780 S
24.16
New Delhi
77 12 32
28 36 50
0.
171 S
24.13
Osaka
135 30 08
34 41 37
0.
1630 S
23.93
Shanghai
121 28 25
31 13 49
0.
1328 S
24.01
Taipei City
121 33 55
25 01 58
0.
1817 S
24.03
Tokyo
139 46 08
35 40 49
0.
1727 S
23.91
Geocentric
..........
..........
-6378.14
5185 S
23.73

6Altitude of each observatory is measured in kilometers above sea level.

7"Distance" refers to the closest approach of the "Site" to the center of Pluto's shadow in the shadow plane. The errors on all closest approach distances are ±650 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.




Table 5: Pluto Occultation Predictions for Individual Sites
Site
KBO Immersion (UT)8
UT Mid-Time
KBO Altitude

Solar Altitude8

KBO Emersion (UT)8

Bangkok
........
17:33:25
50
-58
........
Beijing
17:31:36
17:32:29
21
-30
17:33:23
Hong Kong
........
17:32:29
38
-47
........
Mumbai
17:34:30
17:35:18
46
-45
17:36:06
New Delhi
17:33:52
17:34:49
38
-39
17:35:47
Osaka
........
17:31:35
16
-27
........
Shanghai
17:31:50
17:32:08
27
-36
17:32:27
Taipei City
........
17:32:05
31
-41
........
Tokyo
........
17:31:27
13
-24
........
Geocentric
........
17:35:04
........

8The errors on all times are ± 0:22. (22. seconds; one standard deviation). The solar altitude is given for locations where it is relevant (solar altitude greater than -18 deg). No entry in the immersion and emersion columns indicates that the occultation is not predicted to be visible at that site.




Webpage generated by C. A. Zuluaga (czuluaga@mit.edu) on January 22, 2022

Please direct all inquiries to PAL (planetary-astronomy@mit.edu)