Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation
Equuleus
Right ascension
21h 02m 12.50262s[1]
Declination
+07° 10′ 47.1545″[1]
Apparent magnitude (V)
6.698[2](7.41 + 7.64)[3]
Characteristics
Spectral type
F6V[4]
Astrometry
Radial velocity (Rv)
−4.8±1.6[5] km/s
Absolute magnitude (MV)
2.16±0.18[2]
A
Proper motion (μ)
RA: −9.184[6] mas/yr Dec.: −12.915[6] mas/yr
Parallax (π)
8.8125 ± 0.2481 mas[6]
Distance
370 ± 10 ly (113 ± 3 pc)
B
Proper motion (μ)
RA: −4.238[7] mas/yr Dec.: −17.934[7] mas/yr
Parallax (π)
8.5577 ± 0.0298 mas[7]
Distance
381 ± 1 ly (116.9 ± 0.4 pc)
Details
2 Equ A
Mass
1.73[5]M☉
Radius
3.37[8]R☉
Luminosity
13.087[8]L☉
Surface gravity (log g)
4.05[5] cgs
Temperature
6,561±80[5] K
Metallicity [Fe/H]
0.17[5] dex
Age
1.6[5] Gyr
2 Equ B
Radius
2.74[9]R☉
Luminosity
10.828 L☉
Temperature
6,330[9] K
Other designations
λ Equ, 2 Equulei, BD+06°4731, HD 200256, HIP 103813, LTT 16227, SAO 126482[10]
Database references
SIMBAD
data
2 Equulei is a double star system in the constellation of Equuleus.
The primary component of the 2 Equulei pair is an F-type main sequence star. As of 2015, the secondary had an angular separation of 2.90 arc seconds along a position angle of 213° from the primary.[3] They form a common proper motion pair, two stars at approximately the same distance and moving in the same direction.[4] Gaia EDR3 gives them parallaxes of 8.8125±0.2471 mas and 8.5577±0.0298 mas respectively, although they are flagged as potentially unreliable.[6][7] These parallaxes correspond to a distance of around 380 ly, in contrast to the Hipparcos distance of 260±20 ly for the two stars as a pair.[1]
2 Equulei has been referred to in some sources as λ (Lambda) Equulei, although it was not given that designation by Bayer.
^ abcCite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
^ abCite error: The named reference Holmberg2009 was invoked but never defined (see the help page).
^ abCite error: The named reference WDSC2014 was invoked but never defined (see the help page).
^ abCite error: The named reference abt was invoked but never defined (see the help page).
^ abcdefCite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
^ abcdCite error: The named reference edr3a was invoked but never defined (see the help page).
^ abcdCite error: The named reference edr3b was invoked but never defined (see the help page).
^ abCite error: The named reference dr2a was invoked but never defined (see the help page).
^ abCite error: The named reference dr2b was invoked but never defined (see the help page).
^Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
2Equulei is a double star system in the constellation of Equuleus. The primary component of the 2Equulei pair is an F-type main sequence star. As of...
Alpha Equulei (α Equulei, abbreviated Alpha Equ, α Equ), officially named Kitalpha /kɪˈtælfə/, is a star in the constellation of Equuleus. It is a high...
Beta Equulei, Latinized from β Equulei, is the Bayer designation for a solitary star in the northern constellation of Equuleus. It is faintly visible...
6.1, 6 Equulei. It is divisible in binoculars. 6 Equulei is an astrometric binary system itself, with an apparent magnitude of 6.07. R Equulei is a Mira...
Gamma Equulei, Latinized from γ Equulei, is a double star in the northern constellation of Equuleus. It is located at a distance of around 118 light-years...
Delta Equulei, Latinized from δ Equulei, is the second brightest star in the constellation Equuleus. Delta Equulei is a binary star system about 60 light...
Epsilon Equulei, Latinized from ε Equulei, is a star system of apparent magnitude +5.23 in the constellation of Equuleus. It is located 180 light years...
9 Equulei is an M-type star in the constellation Equuleus. It is an asymptotic giant branch (AGB) star, a star that has exhausted its core helium and...
4 Equulei is a binary star system in the constellation of Equuleus, located about 3° to the east of Alpha Equulei. With an apparent visual magnitude of...
3 Equulei is a single star located in the small northern constellation of Equuleus. It is faintly visible to the naked eye at an apparent visual magnitude...
R Equulei is a class M Mira variable star in the constellation Equuleus. Its brightness varies between a minimum magnitude of 15.0 to a maximum of 8.7...
light years from the galactic core, and it'll come at its closest to the Sun 2.1 million years from now, at a distance of 124.0 light-years. The binary nature...
6 Equulei is a probable (95% chance) astrometric binary star system in the northern constellation of Equuleus, located 380 light years from the Sun. It...
U Equulei (U Equ / IRAS 20547 +0247) is a variable star in the Equuleus constellation with an apparent magnitude of +14.50 in the B band. It lies at an...
Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30...
SY Equulei, also known as HD 203664, is a single variable star located in the equatorial constellation Equuleus. It has an average apparent magnitude...
mass than the Sun and is spinning with a projected rotational velocity of 2.3 km/s. The abundance of iron, an indicator of the star's metallicity, is...
Bastian, U.; Schwekendiek, P.; Wicenec, A. (1 March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30...
Nautical Allowance for Rapid Position Finding". The Geographical Journal. 92 (2). Royal Geographical Society: 137, 145. Bibcode:1938GeogJ..92..133M. doi:10...
solitary star located in the northern constellation Equuleus just next to 3 Equulei It has an apparent magnitude of 6.14, making it barely visible to the naked...
201507 has 1.45 times the mass of the Sun and a slightly enlarged radius of 2.2 R☉ due to its evolved state. It shines with a luminosity of about 9 L☉ from...
University of Illinois The Astronomy Corner: Reference – Star Names v1.1.2 (2006-05-28) from web.archive.org Lebling, Robert W., "Arabic in the Sky"...
(asterism), refers to an asterism consisting of Beta Aquarii and Alpha Equulei. Consequently, the Chinese name for Beta Aquarii itself is 虛宿一 (Xū Xiù...
Conquest of Space. Cambridge University Press. p. 80. ISBN 978-0-521-80040-2. "Constellation boundaries". Retrieved 2018-04-01. "Star Tales – Argo Navis"...
typical examples: A determination of the parallax and mass-ratio of 6 Equulei by van de Kamp, Peter and Lippincott, Sarah Lee, Astronomical Journal,...
"MOST photometry and modeling of the rapidly oscillating (roAp) star γ Equulei". Astronomy and Astrophysics. 480 (1): 223–232. arXiv:0801.0863. Bibcode:2008A&A...
of official IAU constellation borders. The components have a separation of 2″ at a position angle of 282° as of 2016. They have apparent magnitudes of...
was also used in the published search for variability in the stars Gamma Equulei and HD 149728, using 1958 and 1959 data from the refracting telescope....
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