Campaign for a New Eclipsing Cepheid
Active Dates: June 8, 2007 – June 8, 2007
Abstract:
Pojmanski et al. discovered this cepheid several years ago in the course of the ASAS survey. Antipin and collaborators independently discovered the variable on Moscow archive plates. It can also be found in the NSVS (Wozniak et al. 2004, AJ 127, 2436). Russ Robb gives it a spectral classification of F8I, and it is considered a type II cepheid. The light curve looks like a typical cepheid with period 4.1523 days. However, scatter in the light curve was reminiscent of multiperiodic behavior, and so Antipin began CCD observations in 2004. After three years, it was apparent that the system was exhibiting eclipses with period 51.38 days. This is the first known galactic eclipsing binary cepheid (there are three known examples in the LMC, discovered by the MACHO collaboration; see Alcock et al., 2002, ApJ 573, 338). ASAS182612 is a bright (11th mag), easy target with a good reference frame. The amplitude of the cepheid pulsation is about 0.5mag, difficult for visual observers, so this campaign is primarily for CCD and PEP observers. The primary eclipse is about 0.3mag deep, and a secondary eclipse is suspected with perhaps 0.2mag depth. However, the light curve is not well studied, and high-precision, multicolor photometry over several eclipse cycles would be extremely beneficial in understanding this system.
Justification:
The light curve is not well studied, and high-precision, multicolor photometry over several eclipse cycles would be extremely beneficial in understanding this system.
Requested Data Types:
Photometry
Spectroscopy Lines:
No spectroscopy lines provided
Photometry Filters:
No photometry filters provided
Comparison Stars:
No comparison stars provided
Co-Authorship
Observers are not eligible for co-authorship.
Additional Observer Input:
Not provided
Additional Submission Location:
Not provided
Forum URL
N/A
Notes:
Principal Investigator: Pojmanski, G., Pilecki, B., Szczygiel, D. and Antipin, S.V., Sokolovsky, K. V. and Ignatieva, T. I.; Imported Campaign (Alert Notice #351)