Photometry and spectroscopy requested for bright binaries being observed with CHARA - Revised
Abstract:
Juraj Jonák and Dr. Denis Mourard have requested AAVSO observers' assistance in obtaining photometry and spectroscopy of several bright detached binary variable stars in support of their study of these targets to determine their visual trajectories and fundamental stellar parameters, crucial for understanding stellar evolution, interiors, and environments. Jonák writes: "With the recent installment of the CHARA/SPICA interferometer, located at Mt. Wilson, CA, USA we aim to observe a large sample of bright detached binaries in order to determine their visual trajectories. The goal is to use a robust combined model including interferometry, spectroscopy and/or photometry, which will open access to a wide range of direct mass determination and fundamental ingredients of the stellar evolution models."
Justification:
Jonák writes: "Fundamental stellar parameters are the primary data required for an in-depth under- standing of stellar evolution, interiors, and environments...Spectroscopic binary systems provide direct information on stellar mass and structure from the mutual interaction via radial velocity of orbital motion. However, this method is highly dependent on the inclination of the orbit, which cannot be determined purely from spectroscopy...This dependence can be alleviated by combination with observations of eclipses...In fact, the method of simultaneous modelling of spectroscopy and photometry has been a common method since the 1970s. A different approach is utilising interferometric measurements. Although these don’t necessarily require viewing the system edge-on, they demand other constraints on the system...Naturally, the observations are not mutually exclusive, and in fact, using all of them can improve our understanding of the system. The SPICA team has 5 nights per month allocated for observing with the CHARA/SPICA instrument from now through July 2024. However, as our goal is to study the entire orbit, simultaneous observations are not required or preferred." Added in September 2024: Although the CHARA/SPICA observing time has passed, photometry and spectroscopy on these targets is still requested until further notice. This Alert Notice will be updated when coverage is no longer needed.
Requested Data Types:
Spectroscopy, Photometry
Targets
| Name | Magnitude | Variability Type | Photometry Notes | Spectroscopy Notes |
|---|---|---|---|---|
| NSV 5 | 13.14 | RRAB | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| bet Aur | 1.89 | EA/DM |
Cadence: Custom Precision: 100 |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| RR Lyn | 5.52 | EA/DM |
Cadence: Custom Precision: 100 |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| V1143 Cyg | 5.85 | EA/DM |
Cadence: Custom Precision: 100 |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| V1022 Cas | 5.57 | EA |
Cadence: Custom Precision: 100 |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| NSV 6224 | 2.24 | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
|
| NSV 25030 | 5.52 | DSCT: | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| ome Dra | 4.78 | ROT | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| omi Leo | 3.52 | ELL | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| tet Aql | 3.24 | HB | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| d Boo | 4.82 | ELL | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
| 108 Her | 5.62 | ELL | Not Requested |
Cadence: Custom Resolution: 10000 Desired SNR: 100 |
Spectroscopy Lines:
H-beta (4861.0 Å), H-alpha (6563.0 Å)
Photometry Filters:
B (Johnson), V (Johnson), R (Cousins), I (Cousins)
Comparison Stars:
COMPARISON AND CHECK STARS FOR THE PHOTOMETRY TARGETS AND FINDER CHARTS WITH THESE MARKED ARE GIVEN HERE: https://www.aavso.org/aavso-alert-notice-859-backup-copy
Co-Authorship
Observers are not eligible for co-authorship.
Additional Observer Input:
Photometry: Johnson V highest priority, BRI also welcome. Spectroscopy: preferably in the vicinity of a strong line (Hα or Hβ). IMPORTANT: PARAMETERS FOR THE PHOTOMETRY AND SPECTROSCOPY TARGETS ARE GIVEN HERE: https://www.aavso.org/aavso-alert-notice-859-backup-copy Note: Some of the targets are being re-assessed for continued coverage. For the present, please continue to observe all targets. (Elizabeth O. Waagen, September 30, 2024)
Additional Submission Location:
Not provided
Notes:
Principal Investigator: Juraj Jonák, Dr. Denis Mourard (Observatoire de la Côte d’Azur); Imported Campaign (Alert Notice #859)