December 4, 2019
AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Campaigns and Observation Reports: https://www.aavso.org/lpv-maser-2018-campaign
- Long Period Variables: https://www.aavso.org/lpv-maser-2018-campaign-01
Further to AAVSO Alert Notices 645 and 660, Dr. Michael Stroh (Northwestern University) informs us that his SiO maser study on long period variables is being extended through October 2020.
The Mira variable V Cas has been added to the list of targets, bringing the total to 20. Below is a revised list of the targets for this campaign.
| Name | R.A. (2000) | Dec. (2000) | Range | Spec Type | Var Type |
|---|---|---|---|---|---|
| TY Cas | 00:36:59.42 | +63:08:01.7 | 10.1 - 19.0 V | M6-M8 | Mira |
| FI Per | 03:54:56.75 | +48:36:01.9 | 14.0 - 17.8 p | M7 | Mira |
| SY Mon | 06:37:31.34 | -01:23:43.0 | 7.0 - 14.6 V | M6e-M9 | Mira |
| FX Mon | 06:45:05.60 | +09:02:18.5 | 11.0 - 18.0 p | M1-M8 | Mira |
| NSVS 12572573 | 06:45:14.95 | -02:26:35.1 | 13.5 - <17.0 V | M10 | Mira |
| V349 Vul | 19:31:10.47 | +23:30:33.5 | 11.4 - 15.2 V | M8 | Mira |
| RT Aql | 19:38:01.60 | +11:43:18.2 | 7.6 - 14.5 V | M6e-M8e(S) | Mira |
| V353 Vul | 19:49:22.06 | +22:37:39.8 | 13 - <15.5 V | --- | Mira |
| SX Cyg | 20:15:33.53 | +31:04:20.1 | 8.2 - 15.2 V | M7e | Mira |
| AU Cyg | 20:18:32.77 | +34:23:20.5 | 9.5 - 15.3 p | M6e-M7e | Mira |
| V1655 Cyg | 20:25:24.02 | +38:42:35.6 | 12 - 14.8 I | --- | Mira |
| NSVS J2041274+511326 | 20:41:27.45 | +51:13:29.9 | 11.0 - 13.3 R1 | --- | Mira |
| DR Cyg | 20:43:41.01 | +38:09:56.1 | 9.3 - <15.5 p | M5e | Mira |
| V750 Cyg | 20:49:21.17 | +50:31:51.3 | 11.2 - 16.4 V | M5ea | Mira |
| W Cep | 22:36:27.56 | +58:25:34.0 | 7.02 - 8.5 V | M0-M2Iaep+B0/B1 | SR supergiant |
| AL Cep | 22:49:16.89 | +58:35:07.1 | 10.9 - 14.5 p | M5-M6.5e | Mira |
| VX Cep | 22:50:49.45 | +64:15:04.7 | 11.4 - <15.5 p | M8 | Mira |
| V Cas | 23 11 40.72 | +59 41 59.0 | 6.9 - 13.4 V | M5e-M8.5e | Mira |
| V850 Cas | 23 37 39.76 | +58 50 46.2 | 12.9 - 15.2 V | M5/7e | Semiregular |
| V657 Cas | 23 52 04.92 | +61 48 12.5 | 13.9 - <19 V | M8.9-10.4III | Mira |
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.
Charts with comparison stars for each of the targets above may be created using the AAVSO Variable Star Plotter (VSP).
Please submit observations to the AAVSO International Database using the names given in the table.
This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.
----------------------------------
SUBMIT OBSERVATIONS TO THE AAVSO
Information on submitting observations to the AAVSO may be found at:
https://www.aavso.org/webobs
ALERT NOTICE ARCHIVE AND SUBSCRIPTION INFORMATION
An Alert Notice archive is available at the following URL:
https://www.aavso.org/aavso-alert-notices-for-observing-campaigns-and-discoveries
Subscribing and Unsubscribing may be done at the following URL:
https://www.aavso.org/aavso-alert-notice-subscribe
-------------------------------------------------
Please support the AAVSO and its mission -- Join or donate today:
https://www.aavso.org/apps/donate/