BVRcIc Observations and Analysis of the Detached, Polar Spotted Pre-WUMa Binary, V1023 Persei
Abstract
V1023 Per is a polar spotted, but well detached dwarf binary, very likely a Pre-WUMa (T1~ 5250K) eclipsing binary. It was observed on 11 nights in October, November and December, 2015 at Dark Sky Observatory in North Carolina with the 0.81-m reflector of Appalachian State University. Six times of minimum light were determined from our present observations, which include four primary eclipses and two secondary eclipses: HJD Min I = 2457314.92345±0. 0.00011, 2457319.6677±0.0018, 2457346.7709±0.0007, 2457361.6776±0.0001, and HJD Min II = 2457318.65011±0.00007, 2457360.6616±0.0002. In addition, ephemerides were given by VSX, Sergey (2013) and ASAS. We determined 5 times of low light from ASAS observations and 5 more from NSVS. From these we determined both linear and quadratic ephemerides, JD Hel Min I = 2457372.5211±0.0008d d + 0.6775995±0.0000003 X E (1), and JD Hel Min I = 2457372.5211 ±0.0053d + 0.67761398±0.00000065X E +0.00000000171± 0.00000000008 X E2 (2). Its odd light curve is deep but has no totality and reaches maxima just before and after the secondary eclipse, indicating that it has polar spots similar to ER Vul. The period increase may indicate that there is mass exchange with the primary component being the gainer, but the solution reveals that it is well detached. Its presently fixed polar spot indicates that it must have a strong magnetic field and that it is synchronously rotating. The BVRcIc simultaneous 2016 Wilson-Devinney Program (W-D) solution gives a detached solution (primary and secondary components are well under-filling their respective Roche Lobes, 68% and 75%, respectively). The location of the spot region, indeed, models near the pole of the primary (16° colatitude) angled toward the secondary component. Its radius (24°) and Tfact (0.75) also contributes to this conclusion. The small ΔT in the components (~289 K) show that the stars are similar in spectral type despite them being well detached. The inclination is high ~85.19 ±0.04, but there is not a total eclipse due to the high mass ratio (~0.739±0.001). The systems distance is ~390 pc as determined from GAIA DR2. Due to the low galactic position (Longitude = 150.390° Latitude = -1.023°), it is difficult to determine its reddening. However, we estimate the primary components temperature is 5250±500 K.
- Publication:
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American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23517026S