Proposal #127

Proposer: David J Dowhos
Obscode: DDJ
email: davedowh@tbaytel.net

Date of submission: Jan 2, 2020

I am interested in participating in the extended study of Monitoring of LPVs for Maser Study as requested by D .Stroh.
I participated in the first year of this study and contributed over 430 observations using AAVSO's BSM telescopes and VPhot during that time period. I would like to continue to do this until October of 2020.

My data would be of great value in helping to conclude the data for this study.
My proposal would require the use of the BSM telescopes which I already have experience with using the photometric V and B filters in order to process the digital images via VPhot.

Target locations are given using Epoch 2000.
Concerning tis extension, Dr. Stroh writes: "Our approved Karl G. Jansky Very Large Array (VLA) monitoring campaign [that began] in October of 2018 is continuing through October 2020 and observations from AAVSO would be invaluable. In particular, we believe that the strengths of the SiO maser lines we observe at 43 GHz in the radio are correlated with the phase of the stars in our sample and may allow us to probe the density in the stellar envelopes. Our VLA observations will likely occur about once every 3 weeks, thus AAVSO sampling of targets ranging from 2 to 4 weeks through October 2020] will guide our interpretation of the radio observations."

However, the usual cadence for LPVs is one observation every 10 days, and this cadence is requested by the AAVSO. It is asked that more frequent observations not be made.

Stroh continues: "We prefer Johnson V photometry for all stars to standardize our measurements. If this is not possible, redder filters are preferred (if possible), and are considered a bonus if performed in addition to observations in V since these are very red stars." Visual observations are welcomed and encouraged.

Please see Alert Notice 645 for more details on the campaign.