Omicron Persei

Omicron Persei (ο Persei, abbreviated Omicron Per, ο Per) is a triple star system in the constellation of Perseus. From parallax measurements taken during the Hipparcos mission it is approximately 1,100 light-years (330 parsecs) from the Sun.

ο Persei

Location of ο Persei (circled red)
Observation data Epoch J2000      Equinox J2000
Constellation	Perseus
A
Right ascension	03h 44m 19.13377s[1]
Declination	32° 17′ 17.6874″[1]
Apparent magnitude (V)	3.83[2]
B
Right ascension	03h 44m 19.17122s[3]
Declination	32° 17′ 18.5103″[3]
Apparent magnitude (V)	6.68[4]
Characteristics
A
Spectral type	B1III / B2V[5]
U−B color index	-0.75[2]
B−V color index	+0.05[2]
Variable type	ellipsoidal[6]
Astrometry
Radial velocity (Rv)	+12.20[7] km/s
Absolute magnitude (MV)	−4.4[5]
A
Proper motion (μ)	RA: +6.091[1] mas/yr Dec.: −9.732[1] mas/yr
Parallax (π)	3.0224 ± 0.3827 mas[1]
Distance	approx. 1,100 ly (approx. 330 pc)
Orbit[5]
Primary	Aa
Companion	Ab
Period (P)	4.4191447 days
Semi-major axis (a)	33 R☉
Eccentricity (e)	0.0
Inclination (i)	39±15°
Semi-amplitude (K1) (primary)	111.8 km/s
Semi-amplitude (K2) (secondary)	155.0 km/s
Details
Aa
Mass	14[8] M☉
Radius	9.6[5] R☉
Surface gravity (log g)	3.4[8] cgs
Temperature	22,700[8] K
Rotational velocity (v sin i)	70±5[5] km/s
Ab
Mass	10[8] M☉
Radius	8.9[5] R☉
Surface gravity (log g)	4.0[8] cgs
Temperature	21,000[8] K
Rotational velocity (v sin i)	65±15[5] km/s
Age	15[5] Myr
Other designations
Atik, 38 Persei, ADS 2726 AB, BD+31°642, CCDM J03443+3217AB, GC 4461, GSC 02359-01258, HIP 17448, HR 1131, HD 23180, SAO 56673, WDS J03443+3217AB
Database references
SIMBAD	data

The system consists of a spectroscopic binary pair designated Omicron Persei A and a third companion Omicron Persei B.^[9] A's two components are themselves designated Omicron Persei Aa (officially named Atik /ˈeɪtɪk/, the traditional name of the system)^[10][11] and Ab.

Etymology

ο Persei in optical light

ο Persei (Latinised to Omicron Persei) is the system's Bayer designation. The designations of the two constituents as Omicron Persei A and B, and those of A's components - Omicron Persei Aa and Ab - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).^[12]

It bore the traditional name Atik (also Ati, Al Atik), Arabic for "the shoulder". Some sources attribute the name Atik to the nearby, brighter star Zeta Persei.^[13][14] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)^[15] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.^[16] It approved the name Atik for the component Omicron Persei A on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.^[11]

In Chinese, 卷舌 (Juǎn Shé), meaning Rolled Tongue, refers to an asterism consisting of Omicron Persei, Nu Persei, Epsilon Persei, Xi Persei, Zeta Persei and 40 Persei.^[17] Consequently, the Chinese name for Omicron Persei itself is 卷舌五 (Juǎn Shé wu), "the Fifth Star of Rolled Tongue".^[18]

Properties

A light curve for Omicron Persei A, plotted from TESS data^[19]

Omicron Persei A is a spectroscopic binary consisting of a spectral type B1 giant and a type B2 dwarf orbiting each other every 4.4 days. The orbit is near-circular although its inclination is not precisely known. The two stars are separated by approximately 33 R_☉, the exact value depending on the inclination. The primary is approximately one magnitude brighter than the secondary at visual wavelengths.^[5] The binary pair forms a rotating ellipsoidal variable star, which varies in brightness from visual magnitude 3.79 to 3.88 during the orbital period.^[20]

Omicron Persei lies just north of the open cluster IC 348, but is not catalogued as a member. Both IC 348 and Omicron Persei belong to the Perseus OB2 association.^[21]

Culture

• In the TV series Futurama, the fictional planet Omicron Persei 8 is home to medicinal plants and reptilian extraterrestrials who often attack Earth.^[22][23]
• The USS Atik, named for Omicron Persei Aa, was a ship of the United States Navy.

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
3. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
4. Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
5. Stickland, D. J.; Lloyd, C. (1998). "Spectroscopic binary orbits from ultraviolet radial velocities. Paper 28: Omicron Persei". The Observatory. 118: 138. Bibcode:1998Obs...118..138S.
6. 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.
7. 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.
8. Lyubimkov, L. S.; Rachkovskaya, T. M.; Rostopchin, S. I.; Tarasov, A. E. (1997). "The binary system o per: Orbital elements, component parameters, and helium abundance". Astronomy Reports. 41 (5): 630. Bibcode:1997ARep...41..630L.
9. "Displaying next number in catalog HIP => 17448". Multiple Star Catalog. Retrieved 2018-02-19.
10. Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
11. "Naming Stars". IAU.org. Retrieved 16 December 2017.
12. Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
13. Mullaney, James, and Tirion, Wil (2009). The Cambridge Double Star Atlas, Chart 7. University Press, Cambridge. ISBN 978-0-521-49343-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
14. Your Sky Object Catalogue: Named Stars
15. IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
16. "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 5. Retrieved 2018-07-14.
17. (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
18. (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2008-10-25 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
19. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
20. "omi Per". The International Variable Star Index. AAVSO. Retrieved 18 December 2022.
21. Stelzer, B.; Preibisch, T.; Alexander, F.; Mucciarelli, P.; Flaccomio, E.; Micela, G.; Sciortino, S. (2012). "X-ray view of IC 348 in the light of an updated cluster census". Astronomy and Astrophysics. 537: A135. arXiv:1111.4420. Bibcode:2012A&A...537A.135S. doi:10.1051/0004-6361/201118118.
22. "Omicron Persei 8 meaning explored as hilarious Futurama memes spread". The Focus. 30 November 2021. Retrieved 9 October 2022.
23. "How Futurama is related to the new Omicron COVID variant". MARCA. 28 November 2021. Retrieved 9 October 2022.

External links

• Atik