IOTA/IOTA-ES occultation update for 2004 HY78 / UCAC4 304-085707 event on 2023 Jun 16, 08:40 UT Visible from Summary ------- On 2023 Jun 16 UT, the 72.4 km diameter asteroid 2004 HY78 will occult a 14.6 mag star in the constellation Scorpius for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 8.83 mag to 23.43 mag (the magnitude of the asteroid) for at most 3.290 seconds. This update is based on, astrometry for the asteroid kindly provided by the IAU Minor Planet Center. This work has made use of data from the European Space Agency (ESA) mission Gaia (http://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, http://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The event at a glimpse ---------------------- * Rank: 0 * date and approx. time of event: predicted path center does not land on Earth. * geocentric midpoint of event [JD]: 2460111.86679245 * magnitude of target star: 14.60 * magnitude drop [mag]: 8.83 * estimated maximum duration [s]: 3.290 * Moon: 3 % sunlit, 174° distance * Sun: 158° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 72 * 1 sigma uncertainty interval [path widths]: +/- 348.25 * 1 sigma uncertainty interval [seconds]: +/- 2417.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 2.235, +/- 1.324) * 1 sigma uncertainty ellipse (major, minor, PA): (2.374", 1.054", 112°) * approx speed of asteroid's shadow [km/s]: 21.9985 * website for maps: http://www.asteroidoccultation.com Path Coordinates: No Lat/Long file for this path. Data for the target star ------------------------ * name: UCAC4 304-085707 * constellation : Scorpius * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 16 03 22.0203 DE: -29 19 02.584 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 16 03 22.0203 DE: -29 19 02.584 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.200,0.200) * V mag [mag]: 14.6 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: 2004 HY78 asteroid class: TNO approx. diameter [km]: 72 approx. diameter ["]: 0.003 distance from Earth [AU]: 31.22360 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#6 date of fit: 2021 Apr 14 source of used astrometry: MPC, JPL number of used observations: 0 number of rejected observations: 0 time covered by the observations: 1800 Jan 01 - 1800 Jan 01 1 sigma uncertainty ellipse (major, minor, PA): 2.374", 1.054", 112.127° remarks: * orbital elements for 2004 HY78 : Mean anomaly = 17.9162756803 deg Arg. of pericenter = 193.9773432983 deg Long. of node = 25.2837748791 deg Inclination = 12.6085914276 deg Eccentricity = 0.1920563928 Semimajor axis = 39.1375958824 AU Perihelion dist = 31.6209703947 AU Mag: H = 8.30, G = 0.15 Epoch of elements : MJD 60111.36125000 TDT (2023 Jun 16.3613) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#62021Apr14,3.29,2023,6,16,8.803019,-0.570467,-2.590234,-12.124376,2.677736,0.002123,0.000402,0.000001,0.000000 -155.2043,-29.3832,48.12,23.34,False UCAC4 304-085707,16.05611674,-29.3173844,0.00,14.60,0.00,0.0,0,,16.08060080,-29.3832001,8.83,0.00,0,0,0 0,2004 HY78,23.43,72.4,31.2236,0,0,-0.261,0.75,,7.2 0,17.9148,2023,6,16,193.9773,25.2838,12.6086,0.19206,39.13760,31.62097,8.30,5.0,0.15 349.255,2.3743,1.0537,112,1.1134,Known errors,-1.00,-1,-1,-1 20230616_085707,59745.17 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2022 Jun 15, 04:07 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org