Proposal #467

I request time in one of the AAVSOnet Bright-Star Monitor telescopes to obtain photometric data of the sig Ori region, an open cluster containing several young stellar objects. The σ Orionis cluster is part of the Ori OB1b stellar association, commonly referred to as Orion's Belt. Orion OB1 (Ori OB1) is a contingent group of several dozen hot giant stars of spectral types O and B in Orion centered at R.A. 05:38:42, Dec. -02:36:00.
(https://simbad.u-strasbg.fr/simbad/sim-id?Ident=sigma+Ori+cluster&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id).
Members of this cluster are hundreds of low-mass stars, and a significant number of protostars, very young stars that are still gathering mass from their surrounding parent molecular cloud. The cluster was not recognised until 1996 when a population of pre-main sequence stars was discovered around σ Ori.
The Simbad database lists 1,449 objects within a radius of 30 arcmin from R.A. 05 38 42, Dec. -02 36 00, of which over 845 comprise a collection of pre-main sequence and other interesting stars such as YSOs (415 objects), Orion Variables (40 objects, including FU Ori), T Tauri Stars (390 objects), several Herbig Ae/Be Stars, and a few Herbig-Haro objects.
There follows some information on the target area and its desired monitoring:
• ICRS coord. (J2000) of the region of interest – suggested coordinates, within the available FOV range:
(https://simbad.u-strasbg.fr/simbad/sim-coo?Coord=05+38+42-02+36.0&CooFrame=ICRS&CooEqui=2000.0&CooEpoch=J2000&Radius.unit=arcmin&submit=Query+around&Radius=30):
R.A. (J2000) (hrs): 05:36:00 to 05:40:00
Dec (J2000): -02:05:00 to -03:05:00
• Mag.: 10.0 and above (V), for the targets of interest
• Target visual dimension: pinpoint objects
• Desired FOV: 30 arcmin or larger
• Cadence: once a week, three images per observation per filter.
• Initial project duration: 6 months or 26 nightly observations.
• Filters: BVRI.
• Exposure: I leave it to be decided by the AAVSOnet team, depending on the optics and camera to be chosen.

Motivation:
• By monitoring the selected target I will be collaborating with the HOYS initiative (Hunting Outbursting Young Stars), to which I have been invited by its coordinator, Dr. Dirk Froebrich (University of Kent, Dublin, Ireland), and contributing data to the AAVSO photometric database. The HOYS citizen science project works with amateur astronomers on long-term photometric monitoring of nearby young stellar clusters and star-forming regions visible from the Northern Hemisphere to find any occasional stellar outbursting or other interesting objects for detailed follow-up and for the study of star and planet formation processes.
• I will be learning about the observation of an area harboring several young stellar objects. I intend to join the YSO Section of the AAVSO along with the development of this project.