Occultation of 14 Monocerotis by (568) Cheruskia, 2000 Jan. 3
Updated: 1999 Dec. 23From: Jan Manek [jmanek@mbox.vol.cz] Sent: Thursday, December 23, 1999 4:08 AM IOTA/IOTA-ES occultation update for (568) Cheruskia / 14 Monocerotis event on 2000 January 3 visible from Bahamas, Cuba and Mexico Summary Early Monday morning 2000 January 3, the 6.5-mag. star 14 Monocerotis = HIP 31385 = SAO 114085 will be occulted by the 85-km asteroid (568) Cheruskia. 85 km was the long dimension of Cheruskia determined from observations of an occultation by the asteroid observed on Oct. 24. This update is based on USNO/Flagstaff and TMO astrometry for asteroid and HIPPARCOS star position. This calculation gives ~6 path width south shift with occultation time ~1 minute later compared to Edwin Goffin's nominal prediction. Path for this event runs over Bahamas, south of the main islands ~8:12 UT. Following islands are in path - Long I., very NW of Crooked I., Ragged I.Ridge and Jumentos Cays. Later northern Cuba is in path ~8:12.5 UT. Path runs over Yucatan ~8:13.2 UT and later ~8:14.5 UT runs just south of Mexico City. This update used nearly the same observations that Martin Federspiel used for his Dec. 17th update and this one is only a few km south of his central line, a very good agreement. It may be possible to very accurately predict the path of this occultation if any observations are obtained of the 1999 Dec. 30 occultation of another HIP star - see the important note below. Path uncertainity is only 1 path width and star is bright - it is a good opportunity for all within expected errors. The event at one glimpse: * magnitude drop [mag]: 6.0 * estimated maximum duration [s]: 7.5 The occultation path: * approximate width [km]: 90 * uncertainty [path widths]: 1 * uncertainty in time [s]: 10 * map: attached (1 large scale and one more detailed) * remarks: Within uncertainities are also other areas, please consult the map here for details. !!!!!!! Circles along the path are OCCULT exactly calculated centerline points that are MORE ACCURATE than the northern and southern limit lines shown. !!!!!!! Data for the target star: * name: 14 Mon = HIP 31385 = SAO 114085 = PPM 150799 = TYC 0733 00263 1 * constellation: Monoceros * J2000 position [h,m,s; o,',"]: 06h 34m 46.318; +07o 34' 20.93" * position source: HIPPARCOS * estimated accuracy ["]: 0.01" (0.01", 0.01") * Johnson V mag [mag]: 6.46 * B-V [mag]: -0.01 * remarks: Target star is in northen Monoceros, 10 degrees east of zero mag star alpha Orionis and 31' NE of 4.5 mag star 13 Mon = SAO 114034. Target star is primary component of double star STF938 with fainter component having 10.8 mag in PA=213 deg and distance 13.2". Click here. for a finder chart. Data for the minor planet: * orbital information orbit source: calculation Manek source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen) number of used observations: 45 USNO, 26 TMO number of rejected observations: 3 USNO, 1 TMO time covered by the observations: 1998 06 26 - 1999 12 15 rms residuals ["] (RA,DE): 0.08", 0.07" estimated positional accuracy at epoch of event ["]: 0.07" *** Important note *** At least 3 more observations have been made since Dec. 15. Jan Manek plans to use these and any further observations to update the orbit again. We hope to be able to put his latest update for this event on the lunar-occultations.com web site mentioned above by December 31, so be sure to check it. In addition, if any observations are made of the Dec. 30th occultation of another HIP star by Cheruskia, then a further refinement of the Jan. 3rd occultation path to about 10 km or 1/8th path width should be possible. Data for the event: * apparent motion of minor planet ["/h]: 38.95 * angular distance to moon, phase of moon [deg,%]: 144, 11% Centerline path coordinates: Altitude E. Longitude Latitude U.T. star sun ........ shortened .......................... - 69 00 00 + 23 36 13 8 11 25 33 -42 - 71 00 00 + 23 26 17 8 11 34 35 -43 - 73 00 00 + 23 15 01 8 11 44 36 -45 - 75 00 00 + 23 02 22 8 11 54 38 -47 - 77 00 00 + 22 48 24 8 12 05 40 -49 - 79 00 00 + 22 33 05 8 12 16 42 -50 - 81 00 00 + 22 16 26 8 12 27 44 -52 - 83 00 00 + 21 58 29 8 12 39 46 -54 - 85 00 00 + 21 39 12 8 12 52 47 -56 - 87 00 00 + 21 18 38 8 13 04 49 -57 - 89 00 00 + 20 56 46 8 13 18 51 -59 - 91 00 00 + 20 33 38 8 13 31 53 -61 - 93 00 00 + 20 09 13 8 13 45 55 -63 - 95 00 00 + 19 43 35 8 14 00 57 -64 - 97 00 00 + 19 16 42 8 14 15 58 -66 - 99 00 00 + 18 48 36 8 14 30 60 -68 -101 00 00 + 18 19 19 8 14 45 62 -69 -103 00 00 + 17 48 52 8 15 01 64 -71 -105 00 00 + 17 17 16 8 15 17 66 -72 -107 00 00 + 16 44 32 8 15 34 68 -74 -109 00 00 + 16 10 43 8 15 51 70 -75 -111 00 00 + 15 35 49 8 16 08 72 -76 ........ shortened .......................... Calculator: Jan Manek