A-type main sequence star in the constellation Cygnus
29 Cygni Location of 29 Cygni (circled in red)
Observation dataEpoch J2000 Equinox J2000 Constellation Cygnus Right ascension 20h 14m 32.03235s [ 1] Declination +36° 48′ 22.7009″[ 1] Apparent magnitude (V)4.94 - 4.97[ 2] Characteristics Evolutionary stage main sequence [ 3] [ 4] Spectral type A2 V[ 5] B−Vcolor index ± 0.018[ 6] Variable type δ Sct [ 7] Astrometry Radial velocity (Rv )± 2.80[ 6] km/s Proper motion (μ)RA: +68.391[ 1] mas /yr Dec.: +70.446[ 1] mas /yr Parallax (π)24.5456± 0.0724 mas [ 1] Distance 132.9 ± 0.4 ly pc ) Absolute magnitude (MV )1.78[ 6] Details Mass [ 4] M ☉ Radius ± 0.055[ 8] R ☉ Luminosity +3.7 [ 3] L ☉ Surface gravity (log g )± 0.08[ 8] cgs Temperature ± 113[ 9] K Rotational velocity (v sin i )65[ 3] Age +15 +37 [ 10] Myr Other designations b3 Cygni ,29 Cyg ,V1644 Cygni ,BD +36°3955HD 192640HIP 99770HR 7736SAO 69678WDS J20145+3648A2MASS J20143203+3648225[ 11] Database references SIMBAD data Exoplanet Archive data
29 Cygni is a single[ 12] star in the northernconstellation ofCygnus . It is dimly visible to the naked eye as a white-hued star with anapparent visual magnitude of 4.93.[ 6] parallax shift ofmas light years . The star is moving closer to the Earth with a heliocentricradial velocity of −17 km/s.[ 6] Argus Association of co-moving stars.[ 13]
A yellow-lightlight curve for V1644 Cygni, adapted from Gies and Percy (1977)[ 14] This is anA-type main-sequence star with astellar classification of A2 V.[ 5] Delta Scuti variable with afrequency of 0.0267 cycles per day.[ 7] Lambda Boötis [ 15] chemically peculiar star and the first such star to be classified as apulsating variable .[ 4] [ 16] [ 4] magnetic field has been detected with an averaged quadratic field of± 230.7)× 10−4 T [ 17] [ 4] projected rotational velocity of 65 km/s.[ 3] mass of the Sun ,[ 4] Sun's radius ,[ 8] Sun's luminosity from itsphotosphere [ 3] effective temperature of roughly 8,774 K.[ 9]
29 Cygni is listed inmultiple star catalogs as having several companions within′ [ 18] [ 1] b1 Cygni andb2 Cygni , respectively about one and two degrees away, also lie at different distances to 29 Cygni.
Substellar companion [ edit ] Direct imaging of 29 Cygni b by theSubaru Telescope . In 2022, asuperjovian planet,HIP 99770 b , was discovered by direct imaging andastrometry . Its spectral class is between L7 and L9.5, corresponding to a surface temperature of 1,400± 100K .[ 19]
^a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023)."Gaia Data Release 3. Summary of the content and survey properties" .Astronomy and Astrophysics .674 : A1.arXiv :2208.00211 Bibcode :2023A&A...674A...1G .doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source atVizieR .^ 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 : B/GCVS,Bibcode :2009yCat....102025S . ^a b c d e Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities",Astronomy & Astrophysics ,537 : A120,arXiv :1201.2052 Bibcode :2012A&A...537A.120Z ,doi :10.1051/0004-6361/201117691 ,S2CID 55586789 , A120. ^a b c d e f Casas, R.; et al. (May 2009), "Asteroseismological Modeling of the Multiperiodic λ Bootis Star 29 Cygni",The Astrophysical Journal ,697 (1):52– 534,Bibcode :2009ApJ...697..522C ,doi :10.1088/0004-637X/697/1/522 ,hdl :10481/41210 S2CID 120924176 ^a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications",Astronomical Journal ,74 :375– 406,Bibcode :1969AJ.....74..375C ,doi :10.1086/110819 . ^a b c d e Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation",Astronomy Letters ,38 (5): 331,arXiv :1108.4971 Bibcode :2012AstL...38..331A ,doi :10.1134/S1063773712050015 ,S2CID 119257644 . ^a b Rodríguez, E.; et al. 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O.; Kammerer, J.; Lacour, S.; Mérand, A.; Nowak, M.; Stolker, T.; Balmer, W. O.; Marleau, G.-D.; Abuter, R.; Amorim, A.; Asensio-Torres, R.; Berger, J.-P.; Beust, H.; Blunt, S.; Bonnefoy, M. (2025-06-27), "Orbit and atmosphere of HIP 99770 b through the eyes of VLTI/GRAVITY",Astronomy & Astrophysics ,700 : A4,arXiv :2507.00117 Bibcode :2025A&A...700A...4W ,doi :10.1051/0004-6361/202554766 ,ISSN 0004-6361 ^ "29 Cyg" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2019-01-13 .^ De Rosa, R. J.; et al. (2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc",Monthly Notices of the Royal Astronomical Society ,437 (2): 1216,arXiv :1311.7141 Bibcode :2014MNRAS.437.1216D ,doi :10.1093/mnras/stt1932 S2CID 88503488 . ^ Malo, Lison; et al. (January 2013), "Bayesian Analysis to Identify New Star Candidates in Nearby Young Stellar Kinematic Groups",The Astrophysical Journal ,762 (2): 50,arXiv :1209.2077 Bibcode :2013ApJ...762...88M ,doi :10.1088/0004-637X/762/2/88 ,S2CID 118497872 , 88. ^ Gies, Douglas R.; Percy, John R. (February 1977)."Photometric variability of 29 Cygni" .The Astronomical Journal .82 (2):166– 168.Bibcode :1977AJ.....82..166G .doi :10.1086/112023 ^ Murphy, Simon J.; et al. (October 2015), "An Evaluation of the Membership Probability of 212 λ Boo Stars. I. A Catalogue",Publications of the Astronomical Society of Australia ,32 e036: 43,arXiv :1508.03633 Bibcode :2015PASA...32...36M ,doi :10.1017/pasa.2015.34 ,S2CID 59405545 , e036 ^ Mkrtichian, D. E.; et al. (October 2007), "Multimode Pulsations of the λ Bootis Star 29 Cygni: The 1995 and 1996 Multisite Campaigns",The Astronomical Journal ,134 (4): 1713,Bibcode :2007AJ....134.1713M ,doi :10.1086/521434 ^ Bychkov, V. D.; et al. (August 2003), "Catalogue of averaged stellar effective magnetic fields. I. Chemically peculiar A and B type stars",Astronomy and Astrophysics ,407 (2):631– 642,arXiv :astro-ph/0307356 Bibcode :2003A&A...407..631B ,doi :10.1051/0004-6361:20030741 ,S2CID 14184105 . ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog",The Astronomical Journal ,122 (6): 3466,Bibcode :2001AJ....122.3466M ,doi :10.1086/323920 ^ Currie, Thayne; et al. (2023), "Direct imaging and astrometric detection of a gas giant planet orbiting an accelerating star",Science ,380 (6641):198– 203,arXiv :2212.00034 doi :10.1126/science.abo6192 ,PMID 37053312 ^ Bovie, Danielle; Currie, Thayne; Morsy, Mona El; Lacy, Brianna; Kuzuhara, Masayuki; Chilcote, Jeffrey; Tobin, Taylor; Guyon, Olivier; Groff, Tyler (2025-09-02), "Multi-band Spectral and Astrometric Characterization of the HIP 99770 b Planet with SCExAO/CHARIS and Gaia",The Astronomical Journal ,arXiv :2509.02665
