ZZ Boötis

ZZ Boötis is a star system in the constellation Boötes. It varies from magnitude 6.79 to 7.44 over 5 days.[8] Based on its parallax, measured by the Gaia spacecraft, it is about 350 light-years (107 parsecs) away.[1]

ZZ Boötis

Observation data Epoch J2000      Equinox J2000
Constellation	Boötes
Right ascension	13^h 56^m 09.5178^s[1]
Declination	+25° 55′ 07.3547″[1]
Apparent magnitude (V)	6.79 - 7.44[2]
Characteristics
Spectral type	F2 IV-V + F2 IV-V[3]
B−V color index	+0.36[4]
Variable type	Algol[2]
Astrometry
Radial velocity (Rv)	-29.50[5] km/s
Proper motion (μ)	RA: −97.004±0.057[1] mas/yr Dec.: −6.164±0.061[1] mas/yr
Parallax (π)	9.3114 ± 0.0381[1] mas
Distance	350 ± 1 ly (107.4 ± 0.4 pc)
Absolute bolometric magnitude (Mbol)	2.17 / 2.30[3]
Orbit[3]
Period (P)	4.991744 d
Inclination (i)	88.6 ± 0.1°
Semi-amplitude (K1) (primary)	93.7 ± 2.1 km/s
Semi-amplitude (K2) (secondary)	94.0 ± 2.1 km/s
Details
ZZ Boo A
Mass	1.71 ± 0.06[3] M☉
Radius	2.28 ± 0.06[3] R☉
Luminosity	10.7[3] L☉
Surface gravity (log g)	3.72 ± 0.10[6] cgs
Temperature	6860 ± 20[6] K
Metallicity [Fe/H]	−0.10 ± 0.08[6] dex
Rotational velocity (v sin i)	11.9 ± 0.4[6] km/s
ZZ Boo B
Mass	1.70 ± 0.06[3] M☉
Radius	2.15 ± 0.06[3] R☉
Luminosity	9.95[3] L☉
Surface gravity (log g)	3.84 ± 0.10[6] cgs
Temperature	6930 ± 20[6] K
Rotational velocity (v sin i)	19.3 ± 0.8[6] km/s
Other designations
ZZ Boo, HD 121648, HIP 68064, SAO 83080, BD+26°2508[7]
Database references
SIMBAD	data

Observational history

In 1950 Grigory Shajn determined that this star is a double lined spectroscopic binary with, with an approximate period of 4.96 days. Sergei Gaposchkin found from an examination of photographic plates, in 1951, that it was an Algol type eclipsing binary system.[9] The primary and secondary eclipses are of equal depth, 0.65 magnitudes, meaning the brightness drops by nearly half.[2] The eclipses make up only 6% of the orbital period.[8]

ZZ Boötis is a binary star system, specifically an eclipsing binary.[8] The component stars appear to be of almost equal mass, differing by only 3%.[4]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. Samus, N. N.; Durlevich, O. V.; et al. (2009). "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. Bibcode:2009yCat....102025S.
3. Cester, B.; Giuricin, G.; Mardirossian, F.; Mezzetti, M. (1978). "Revised spectrographic and photometric elements of ZZ Boo". Astronomy and Astrophysics Supplement Series. 32: 347–350. Bibcode:1978A&AS...32..347C.
4. Popper, D. M. (1983). "The F-type eclipsing binaries ZZ Bootis, CW Eridani, and BK Pegasi". Astronomical Journal. 88: 1242–56. Bibcode:1983AJ.....88.1242P. doi:10.1086/113415. ISSN 0004-6256.
5. Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
6. Kang, Young-Woon; Yushchenko, Alexander; Hong, Kyengsoo; Kim, Sungeun; Yushchenko, Volodymyr (2012). "Chemical Composition of the Components of Eclipsing Binary Star ZZ Bootis". The Astronomical Journal. 144 (2): 35–45. Bibcode:2012AJ....144...35K. doi:10.1088/0004-6256/144/2/35.
7. "ZZ Boo". SIMBAD. Centre de données astronomiques de Strasbourg.
8. Watson, Christopher (4 January 2010). "ZZ Boötis". AAVSO Website. American Association of Variable Star Observers. Retrieved 5 August 2014.
9. Gaposchkin, S. (1951). "The system of RZ Eridani and a new bright eclipsing variable with double-lined spectrum". The Astronomical Journal. 56: 125. Bibcode:1951AJ.....56..125G. doi:10.1086/106546.