International Occultation Timing Association
Link to Steve Preston's prediction
Cloud cover predictions toward bottom of page, updated 12/06 8:305PM CST
NA-Satellite Search Area
Finder charts, The 3 charts are naked eye, 4 charts are for finder scopes and mighty mini's, and 5 charts are for 80mm "midi" refractors; the ones named "end" are the last pre-point ones, centered on the target star, 18 Aurigae, as is the only level 7 chart for an 8-in. SCT. David
6th-mag. occultation, Dec. 6/7 n.Florida-s.Texas-s.Baja
Update for the occultation of 6.5-mag. 18 Aurigae by (55) Pandora tomorrow night (Dec. 6pm)
This very bright asteroidal occultation provides an opportunity to discover satellites of Pandora hundreds of miles from the predicted path with a strong signal-to-noise ratio; a map for the “satellite search” shows the area between two dark gray lines about 700 km north and south of the predicted path on a map on Steve Messner’s page for the event at
https://occultationpages.com/events/20191207_55_Pandora.html . It gives near the top, the link to Steve Preston’s page for the event, with his finder charts and other event details. Preston recently updated his prediction to match JPL orbit solution #71 which in turn was updated by Davide Farnocchia, now including Gaia DR2 observations of Pandora. The new path is almost identical to the previous one computed by Preston, but the errors are smaller; unluckily, the Gaia error ellipse is elongated in the direction perpendicular to the path, so it’s 12 km 1-sigma, still a good result in which I believe we can have good confidence, considering the good agreement with Preston’s independent result, and the great result (error less than 2 km) for the July 29th Phaethon occultation whose orbit was so successfully updated by Farnocchia by similar means.
On 2007 Feb. 18, another occultation by Pandora was observed from 9 stations across the USA, showing an elongated shape, 91 by 58 km; a few other Pandora events have been observed, but only from one station. On Steve Messner’s page is the predicted DAMIT shape model for our Dec. 6/7 occultation; its shape is not very elongated, so apparently the long axis isn’t broadside to us this time. Also later today, Steve Messner will post star charts for the occultation that I prepared for south Texas (with zenith up; then north happens to be to the left). The charts will be similar for Jacksonville, FL, but rotated a little. The pre-point line of declination is shown, with the times for where the path crosses Texas Hwy 16 (at 4:50:43 UT of Dec. 7 UT), but unless you plan to set up more than one station (as we do), then you can just use the “end” charts with 18 Aurigae centered, to locate 18 Aurigae in its distinctive asterism; there’s no pre-point opportunity that’s easier for locating the object. The UT of the occultation in Jacksonville is 4:48:25 (= 11:48:25 pm EST Dec. 6 EST), or 2.3 min. earlier than at Texas Hwy 16 (so if you try pre-pointing in Jacksonville with these charts, subtract 2.3 min. from the times shown). In any case, observers should note that 4.9-mag. 19 Aurigae, rather brighter than 18 Aurigae, is only 8’ east-southeast of 18; and an 8.1-mag. star is only 1.5’ southwest of 18 Aurigae. 18 Aurigae also has an 11.9-mag. companion 4” south; it will be occulted in northern Canada, Germany, and Poland, but completely unobservable with the 6th-mag. star unocculted there.
We have reserved a room at the Texas Inn and Suites on the north side of Tilden, Texas, about 20 miles north of the path. If you can join our effort to observe the occultation from sites near Hwy 16, let me know by email or cell phone (text or voice), 301-526-5590. We will arrive in Tilden about midnight tonight, and would like to meet at the motel late tomorrow afternoon, by about 4:30 or 5pm; by 6:00pm, we plan to start work at the first station 15 miles south of Tilden. If you have to arrive later than 6pm, we can coordinate meeting by cell phone, at either the first station, or one of the other ones farther south. We have equipment to deploy 11 stations, but we will have time only to deploy 7 or 8 ourselves; others could help use our simple systems to obtain more chords across Pandora.
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I wrote on Nov. 30 (along with the Dec. 4 Kugultinov occ’n, whose data have been removed)
6th-mag. occultation, Dec. 6/7 n.Florida-s.Texas-s.Baja
Please inform others in your area of this occultation, if you live in or near one of the paths. If you can observe it yourself, please let me or Occult Watcher (IOTA’s free asteroidal occultation prediction and observation-coordination software available from http://www.hristopavlov.net/OccultWatcher/publish.htm) know, so that mobile observers can avoid duplicating your chord. The rank 99 occultation of 18 Aurigae by (55) Pandora will occur Friday evening, 4:48 - 4:52 UT Dec. 7. Pandora is expected to be 72 km in diameter, producing an occultation up to 7s long. The star is 6.5-mag. HIP 24832 = SAO 57893 = 18 Aurigae, spectral type A7V, at J2000 RA 5h 19m 23.8s, Dec +33 deg. 59’ 07”, a little more than 5 deg. n.n.w. of 2nd-mag. beta Tauri (El Nath). The path crosses n. Florida (Jacksonville) at 4:48 UT (11:48pm EST Dec. 6 EST); just s. of New Orleans at 4:49 UT (10:49pm CST Dec. 6 CST); over s. Texas (4:50 UT; Corpus Christi & Laredo in the path); n. Mexico at 4:51 UT (Monclova and Sinaloa); and over Baja California sur at 4:52 UT (9:52pm MST; just n. of La Paz). The long-range cloud forecast shows clear skies over s. Texas and the path over n.e. Mexico, and mostly cloudy or unsettled over the other parts of the path in N. America.
I wanted to deploy multiple stations across the predicted path west of Jacksonville, Florida, but if the current cloud forecasts hold up, I will change my plans, to observe instead from the area south of San Antonio, probably from sites near Texas Hwy 16 north and south of Freer. Let me know if you might be interested in helping out, joining the effort to observe in that area.
[Since then, I did change my plans, flying to San Antonio late Dec. 5, and staying that night and the next at the Texas Inn and Suites in Tilden, Texas, about 20 miles north of the path; more will be distributed soon].