2024 Occultations by Trojan Asteroids - Updated 2024 April 23
Next Campaign for August 11th occultations by Patroclus and Menoetius, best NM and TX
A brighter Patroclus/Menoetius Occ'n will occur Oct. 7 in Baja and w. Texas (low there)
These occultations are described and illustrated in this .pdf document. It includes several hot links to external Web pages, but links to internal files, especially the .xml input files used by the Occult program, are given below. The .pdf document will be updated less frequently than this page. A text file version of the table in the .pdf document is here. The Occult map for the 2024 April 22nd (UT; April 21st, local date) occultation of a 13.8-mag. star by the 63-km Trojan (15440) Eioneus is here; it and a short message about the event were distributed to the IOTAoccultations list, and to #iota on Lucyocc.slack.com 5 days before the event. Other past 2024 events were similarly announced, including for the Lucy target events on Jan. 5 (Orus), Feb. 26 (Polymele), and Mar. 25 (Eurybates), all described, with preliminary results, in the .pdf document. _ _ _ _ _ OCCULTATIONS BY (617) PATROCLUS AND MENOETIUS, esp. OCT. 7 During 2024, there are three occultations of stars brighter than mag. 14.5 by the interesting (617) Patroclus/Menoetius binary asteroid system, the last target of NASAs Lucy mission, in North America. The ones on Aug. 11 and Nov. 12 are shown on the map and table in the .pdf document, but another event has just been found, of an 11.6-mag. star whose path crosses n.w. Mexico and w. Texas (low); see this Occult map; conditions are rather good in northern Baja California Sur and southern Sonora. According to Occult and the JPL orbit, the path for Menoetius is virtually the same as for Patroclus, but that will likely change when we get a good prediction for SwRI, which has been requested. For other parts of the world, we found one reasonable event, on Oct. 18 with the path from Taiwan, across s. Asia to Turkey; the Menoetius path is just north of the one for Patroclus, but that will likely change with a SwRI prediction. The Patroclus path passes just s. of Iwo Jima and one other w. Pacific island. Again, a SwRI prediction has been requested. _ _ _ _ _ UNSAFE WARNING WHEN OPENING SWRI WEB PAGES Recently, whenever I open a SwRI Web page, I get a warning that "Your connection is not private", but I have not found any real problem going to their pages. It's annoying, but you just need to click on the "Advanced" box at the bottom, and then click on "Proceed to lucy.swri.edu (unsafe)" on the next page you get. This did not happen a week ago; it seems to be something new, at least with Chrome and Edge. _ _ _ _ _ 2022 OCTOBER 23RD BRIGHT OCCULTATION BY EURYBATES RESULTS A large effort was made for the 2022 October 23rd occultation of an 8.7-mag. star by Eurybates in western Europe. SwRI's prediction page for the event is at https://lucy.swri.edu/occ/predictions/20221023Eurybates/ . Well over 100 stations tried the event, but most were clouded out; 15 positive chords were recorded across the asteroid, mainly by French observers who found breaks in the widespread cloud cover; one station in northern Sweden recorded it. Euraster has a sky-plane plot of the chords. and observation details are here. The links for the above from 2023 don't work since starting this year, the previous euraster.net is now replaced with euraster.ericfrappa.com. The SwRI link is also new, with a recent restructuring of SwRI's predictions pages. _ _ _ _ _ OCCULT INPUT .XML FILES FOR 2024 When you open these files with your Web browser, you should get a display that looks like this. The larger files may take a couple of minutes to show this appearance, showing a messed-up display before then. Once the proper view appears, right-click anywhere on the display, then "Save as" to a directory on your computer; the best directory is the \Asteroid\ subdirectory in your Occult\ directory. Better predictions are often available via Occult Watcher and at Steve Prestons asteroidal occultation prediction site, the SwRI occultation prediction Web site, and the Lucky Star prediction site, as described near the end of the main .pdf document linked to at the top. You can use the input files with the free Occult4 program, as described in this .pdf document, to generate a list of these events for the rest of 2024 filtered for a specified distance from your location and to the magnitude limit you can reach. You can also generate maps showing the paths of these events across your region, like the one for North America in the .pdf document (link near the top of this page); to identify the paths, you need to consult the individual Occult maps by clicking on each line for the selected events in your Occult listing. The selection can be filtered many ways with the colored boxes at the top of the Occult listing, the most important being the lat./long. boundaries (for n., s., e., and w.); remember that longitudes west of Greenwich are negative. Most of the input files below were created in late March, so "the rest of 2024" starts with those dates. For the 22 Trojan events mapped and tabulated in the main .pdf document 194 2024 Worldwide Lucy Trojan events to mag. 16, 143 for rest of 2024 15 2024 N. American Lucy Trojan events to mag. 16, 6 for rest of 2024 339 Worldwide events for our selected Trojans to mag. 14 for rest of 2024; 26 N. American events for our selected Trojans to mag. 14 for rest of 2024; these include non-Lucy Trojans ocvered by the Lucky Star Project, which usually will have better predictions for them. Currently, the SwRI Lucy occultations prediction site includes all of their currated events, but it is not complete for all parts of the world. If an event you find for a Lucy-target event from our files here, is not on SwRI's currated list, you should send a message to Brian Keeney, email bkeeney at gmail dot com, giving the date, asteroid, and general area, and he can prepare and post a Google map for the event on their prediction site; you should do this, as their predictions include unpublished observations not available to IOTA snd JPL. Our predictions for occultations by 11351 Leucus are quite accurate because SwRI published details of the observations they collected from several of their occultation campaigns, and those have been incorporated into the JPL Horizons system that IOTA relies on for most of their predictions, but for the other Lucy targets, our paths can be more than a path-width in error and only SwRI has accurate orbits for them. Also, see the page of bright 2024 asteroidal occultations in North America. Besides giving information about the brightest main-belt asteroidal occultations in North America during 2024, it has links to pages for occultations by other important occultations in North America, including near-Earth asteroidal occultations and special main-belt asteroidal occultations (objects with known or suspected moons, unusual shapes, etc.). _ _ _ _ _ 14th ASTEROIDS, COMETS, METEORS CONFERENCE, 2023 JUNE 18-23 This conference, abbreviated ACM 2023, was held in Flagstaff and online during 2023 June. Clicking on "Program and Presenter Information", including the program with links to abstracts, you can see the interesting agenda, including several papers using results from occultation observations. Highlights of the conference relating to occultations are linked to from here. ______ David and Joan Dunham, 2024 April 18, updated April 19 and 23 e-mail: dunham@starpower.net cell phone: 301-526-5590