YSOs

Alert Notice 846: AB Aur HST observations on January 17-18

Note: The HST observations of AB Aur scheduled for 2024 January 17-18 have been cancelled because HST has gone into safe mode. Rescheduling information will be given here and in the forum threads below when available. In the meantime, please continue to observe AB Aur according to the cadence given below.  -  Elizabeth O. Waagen, January 17, 2024

January 15, 2024

Alert Notice 842: AB Aur monitoring requested for HST observations

November 15, 2023
 
Notes: In the original version of this Alert Notice, the Rc magnitude of the CHECK star was in error. The correct Rc magnitude for the CHECK star is 11.382.  -  Elizabeth O. Waagen, December 12, 2023
 
A webinar on AB Aur and this campaign took place on November 19, 2023. See below under "What to Expect" for details.

The YSO Zoo

...and welcome to the Zoo!

Part of the reason why a YSO section is needed is to try and make some sense of how the different types of variable star fit into some sort of scheme. Should we view the various types as distinct, or should we look at behaviour instead? Pursuing the zoo theme for a while, how do the various types of YSO fit into the interstellar ecosystem?

Suggested Observing Cadences for Variable Star Types

Something you need to consider carefully, and a question that comes up often with new observers is "How often should I observe my program stars?" The answers depend largely on the type of stars you are observing. The following table is a general guideline. As you learn more about the different types of variables, and the personalities of some of the specific stars you choose to observe, you may decide to observe them more or less often than suggested here.

New Observing Section Created to study Young Stellar Objects (YSOs)

 Michael Poxon has taken it upon himself to head a new AAVSO section on his favorite class of variable star: Pre-Main Sequence Stars (YSO/PMS). The AAVSO has had a long history of working with such objects, especially the "Orion variables" that were monitored by many visual observers for years.