Omicron Persei

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title: "Omicron Persei" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["perseus-(constellation)", "bayer-objects", "b-type-giants", "b-type-main-sequence-stars", "spectroscopic-binaries", "stars-with-proper-names", "flamsteed-objects", "bright-star-catalogue-objects", "henry-draper-catalogue-objects", "hipparcos-objects", "durchmusterung-objects"] description: "Triple star system in the constellation Perseus" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/Omicron_Persei" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Triple star system in the constellation Perseus ::

| name = ο Persei |image= |image=Perseus constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=Omicron Persei |x=450|y=907 |caption=Location of ο Persei (circled red) | epoch = J2000 | constell = Perseus | component1 = A | ra1 = | dec1 = | appmag_v1 = 3.83 | component2 = B | ra2 = | dec2 = | appmag_v2 = 6.68 | component1 = A | class = B1III / B2V | b-v = +0.05 | u-b = −0.75 | variable = ellipsoidal | radial_v = +12.20 | component2 = A | prop_mo_ra2 = +6.091 | prop_mo_dec2 = −9.732 | parallax2 = 3.0224 | p_error2 = 0.3827 | parallax_footnote2 = | absmag_v = −4.4 | reference = | primary = Aa | name = Ab | period_unitless = 4.4191447 days | axis_unitless = | k1 = 111.8 | k2 = 155.0 | eccentricity = 0.0 | inclination = | component1 = Aa | mass = 14 | temperature = 22,700 | luminosity = | radius = 9.6 | gravity = 3.4 | rotational_velocity = | component2 = Ab | mass2 = 10 | temperature2 = 21,000 | radius2 = 8.9 | gravity2 = 4.0 | rotational_velocity2 = | age_myr2 = 15 | names = 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 | Simbad = 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.

The system consists of a spectroscopic binary pair designated Omicron Persei A and a third companion Omicron Persei B. A's two components are themselves designated Omicron Persei Aa (officially named Atik , the traditional name of the system){{cite book |last1=Kunitzsch |first1=Paul |last2=Smart |first2=Tim |date = 2006 |edition = 2nd rev. |title = A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations |publisher = Sky Pub |location = Cambridge, Massachusetts |isbn = 978-1-931559-44-7

Etymology

::figure[src="https://upload.wikimedia.org/wikipedia/commons/3/36/Omicron_Persei.jpg" caption="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).

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. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN){{citation | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN) | publisher=International Astronomical Union | access-date=22 May 2016 | postscript=. | archive-date=10 June 2016 | archive-url=https://web.archive.org/web/20160610172014/https://www.iau.org/science/scientific_bodies/working_groups/280/ | url-status=dead

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. Consequently, the Chinese name for Omicron Persei itself is 卷舌五 (Juǎn Shé wu), "the Fifth Star of Rolled Tongue".

Properties

::figure[src="https://upload.wikimedia.org/wikipedia/commons/1/1e/OmicronPerLightCurve.png" caption="access-date=8 December 2021}}"] ::

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 , the exact value depending on the inclination. The primary is approximately one magnitude brighter than the secondary at visual wavelengths.

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.

Culture

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

References

References

1. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues.
2. {{cite Gaia EDR3. 216718178537987968
3. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics.
4. (1998). "Spectroscopic binary orbits from ultraviolet radial velocities. Paper 28: Omicron Persei". The Observatory.
5. (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.
6. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics.
7. {{cite Gaia EDR3. 216718178536050176
8. (1997). "The binary system o per: Orbital elements, component parameters, and helium abundance". Astronomy Reports.
9. "Displaying next number in catalog HIP => 17448". Multiple Star Catalog.
10. "Naming Stars". IAU.org.
11. (2010). "On the naming convention used for multiple star systems and extrasolar planets".
12. Mullaney, James. (2009). "The Cambridge Double Star Atlas, Chart 7". University Press, Cambridge.
13. [http://www.fourmilab.ch/yoursky/catalogues/starname.html Your Sky Object Catalogue: Named Stars]
14. "WG Triennial Report (2015-2018) - Star Names".
15. {{in lang. zh ''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.
16. {{in lang. zh [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive. link. (2008-10-25 , Hong Kong Space Museum. Accessed on line November 23, 2010.)
17. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute.
18. "omi Per". AAVSO.
19. (2012). "X-ray view of IC 348 in the light of an updated cluster census". Astronomy and Astrophysics.
20. (30 November 2021). "Omicron Persei 8 meaning explored as hilarious Futurama memes spread".
21. (28 November 2021). "How Futurama is related to the new Omicron COVID variant".

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