The Occultation of a 15.4 mag combined by Trojan Asteroid Alcathous

Aug 1, 2024 at 4:38:12 am PDT

This is a high rank and high value event with path over Santa Cruz and also over MIRA Observatory and the rest of Monterey Bay and the southern Santa Cruz Mtns. It's also at a good altitude of 69 degrees at event time, and 64 degrees 20 minutes earlier. Low enough to clear our tripod interference, but high enough to minimize aerosol extinction. The thin 10% waning crescent moon is only 7 degrees up low in the southeast and not a problem. We should have very dark skies to work with. But with the faintness, it may be good to try to reserve a night at MIRA Observatory with the 36" scope. Or at Fremont Peak Observatory's 30" scope. I'll need to get checked out on it and conduct a public evening up there to qualify for that. Or Kirk.

J2000 coords
23h 30' 52.03s
+17 29 50"

J(Date) Position
23h 32 06.9
+17 37 53"

The duration is 9.8 seconds, allowing integration to get a good signal. The depth of the occultation is only 0.8 magnitude, however, so that will be a challenge and require good S/N. For our 8" scopes, I believe that will require at least 2s integrations to get this. That's still 5 data points within the occultation. However, much better data will be possible with the 36" and 14" scopes at MIRA. We might also want to try to station Karl and Karla at Cabrillo Observatory on the 12". Since the event is at 4am, we would have time the day before to get the gear set up and checked out on the 12" scope. I calculated that the 12" scope should improve on our 8" scopes by 1 full magnitude. We might be able to get away with 1s integrations on the 12" scope, which would permit better astrometry and orbit improvement.