6 Equulei

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title: "6 Equulei" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["a-type-main-sequence-stars", "ap-stars", "equuleus", "durchmusterung-objects", "flamsteed-objects", "henry-draper-catalogue-objects", "hipparcos-objects", "bright-star-catalogue-objects"] description: "Star in the constellation Equuleus" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/6_Equulei" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Star in the constellation Equuleus ::

|name = 6 Equulei |epoch = J2000.0 (ICRS) |constell = Equuleus |ra = |dec = |appmag_v = 6.07 |type = main sequence |class = A2 Vs (A1 Si Sr Cr) |b-v = +0.02 |u-b = +0.04 |variable = |radial_v = +6.9 |prop_mo_ra = –0.982 |prop_mo_dec = +17.687 |pm_footnote = |parallax = 7.36 |p_error = 0.81 |parallax_footnote = |absmag_v = +0.236 |mass = |radius = |luminosity = |temperature = |metal_fe = |gravity = |rotational_velocity = 65 |age_myr = |names = |Simbad = 6+Equ

6 Equulei is a probable (95% chance) astrometric binary star system in the northern constellation of Equuleus, located 440 light years away. It is barely visible to the naked eye as a dim, white-hued star with an apparent visual magnitude of 6.07. The system is moving further away from the Earth with a heliocentric radial velocity of +6.9 km/s. It forms a wide optical double with γ Equulei, at an angular separation of 336 arcseconds in 2011.

The visible component is an Ap star with a stellar classification of A2Vs, matching the evolutionary state of an A-type main sequence star while displaying "sharp" absorption lines. It is an estimated 460 million years old with a projected rotational velocity of 65 km/s. The star has 2.4 times the mass of the Sun and around 2.7 times the Sun's radius. It is radiating 49 times the luminosity of the Sun from its photosphere at an effective temperature of 9,339 K.

References

References

1. (May 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy and Astrophysics.
2. Wilson, Ralph Elmer. (1953). "General Catalogue of Stellar Radial Velocities". [[Carnegie Institution of Washington]].
3. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory.
4. {{Cite DR3. 1744655199270929152
5. "6 Equ -- Star in double system". [[Centre de Données astronomiques de Strasbourg]].
6. "HD 104538". WolframAlpha.
7. (March 2007). "Proper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data". Astronomy and Astrophysics.
8. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics.
9. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal.
10. (November 2007). "Validation of the new Hipparcos reduction". [[Astronomy and Astrophysics]].

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