Request for regular monitoring of the symbiotic variable RT Cru
Abstract:
Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) and colleagues have requested AAVSO observer assistance in their campaign on the symbiotic variable RT Cru. Weekly or more frequent monitoring in B and V (and visually) beginning now is requested in support of upcoming Chandra observations still to be scheduled. Note: The request for ongoing monitoring has been extended indefinitely, even beyond the 2027 end date currently given in this notice.
Justification:
RT Cru is a fascinating member of a new class of hard X-ray emitting symbiotic binaries. The RT Cru system contains a high-mass white dwarf accreting from a mass-losing M giant. The white dwarf is surrounded by an accretion disk fed by the wind of the red giant. They plan Chandra observations of RT Cru in the near future that will help understand the characteristics of the accretion onto the white dwarf in this sub-class of symbiotics. This is an important step for determining the precursor conditions for formation of a fraction of asymmetric Planetary Nebulae, and the potential of symbiotic systems as progenitors of at least a fraction of Type Ia supernovae.
Requested Data Types:
Photometry
Targets
| Name | Magnitude | Variability Type | Photometry Notes | Spectroscopy Notes |
|---|---|---|---|---|
| RT Cru | 10.90 | ZAND |
Cadence: Weekly Precision: 100 |
Not Requested |
Spectroscopy Lines:
No spectroscopy lines provided
Photometry Filters:
B (Johnson), V (Johnson), Other (Please Specify)
Comparison Stars:
Finder charts with comparison stars may be created using the AAVSO Variable Star Plotter (VSP, https://apps.aavso.org/vsp/).
Co-Authorship
Observers are not eligible for co-authorship.
Additional Observer Input:
Regular optical monitoring (B and V photometry) of this source (on a weekly basis if possible) is requested. Visual observations are also encouraged (= Other entry under photometry filters). RT Cru varies between 11.2 and 12.6 visual. Charts for RT Cru with comparison star sequence may be created using the AAVSO Variable Star Plotter (VSP, http://www.aavso.org/vsp). Photometrists should use the photometry table provided there for RT Cru.
Additional Submission Location:
none
Notes:
Principal Investigator: Dr. Margarita Karovska; Imported Campaign (Alert Notice #503)