1 Persei

Star in the constellation Perseus 1 Persei Perseus constellation map.svg center 260 right Red circle.svg 8 1 Per 901 204 Location of 1 Persei (circled) J2000.0 Perseus 01 51 59.32008 +55 08 50.5837 5.49 - 5.74 - 5.85 B1.5V eclipsing binary 12.716 (74) −8.410 (79) 2.6944 0.0888 −1.37/−1.77 1 Persei A 1 Persei B 25.935951 0.000003 days 0.3768 0.0014 88.048 0.002 2443563.466 0.005 HJD 109.83 0.10 97.4 0.1 91.2 0.1 Primary 6.95 21,500 3.29 2,188 4.25 115 1.45 days Secondary 7.42 22,000 3.86 3,311 4.14 140 1.40 days V436 Persei 533 11241 +54 396 8704 22690 1+Per 1 Persei (1 Per) is an eclipsing binary star in the constellation Perseus. Its uneclipsed apparent magnitude is 5.49. The binary star consists of two B2 type main-sequence stars in a 25.9 day eccentric orbit. The stars are surrounded by a faint cloud of gas visible in mid-infrared, although whether they are the origin of the gas or simply passing through it is unclear. Observational history thumb|left|A visual band light curve for V436 Persei, adapted from Janik et al. (2003) The possible eclipsing binary nature of 1 Persei was first noticed by Donald Kurtz in 1977 when it was used as a comparison star to test for photometric variability of HD 11408. In 1979 French amateur observers succeeded in determining an orbital period of 25.9 days. During the primary eclipse, the brightness drops to magnitude 5.85. In the secondary eclipses, the brightness drops to magnitude 5.74. The eclipses each last for approximately 25 hours. References 1 Persei, a low amplitude eclipsing binary, has a period of 25.939 days and an elliptical orbit http://geos.upv.es/index.php/publications/Geos-Circulars/GEOSEB02/ Figer Alain Maurin Luc GEOS Circular on Eclipsing Binaries EB 2 1979 2 1979GEOCE...2.....F 408620409702994432 2009yCat....102025S VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013) VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1 etal Samus N. N. Durlevich O. V. 2009 Search for forced oscillations in binaries. I. The eclipsing and spectroscopic binary V436 Persei = 1 Persei Harmanec P. Hadrava P. Yang S. Holmgren D. North N. Koubský P. Kubát j. Poretti E. 1 Astronomy and Astrophysics 319 2 867–880 1997 1997A&A...319..867H Search for forced oscillations in binaries. IV. The eclipsing binary V436 Per revisited Janík J. Harmanec P. Lehmann H. Yang S. Božić H. Ak H. Hadrava P. Eenens P. Ruždjak D. Sudar D. Hubeny I. Linnell A. P. 1 Astronomy and Astrophysics 408 2 611–619 2003 2003A&A...408..611J 10.1051/0004-6361:20030960 free The photometric variability of 1 Per Kurtz D. W. Publications of the Astronomical Society of the Pacific 89 939–940 1977 1977PASP...89..939K 10.1086/130251 free 1 Per: a new eclipsing binary with a long period and an elliptical orbit https://konkoly.hu/pub/ibvs/2001/2036.pdf North P. Rufener F. Figer A. Maurin L. 1 Information Bulletin on Variable Stars 2036 1981 1 1981IBVS.2036....1N Category:Perseus (constellation) Category:B-type main-sequence stars Category:Algol variables Persei, 01 Category:Eclipsing binaries Persei, V436 008704 0533 011241 Category:Durchmusterung objects