Binary star system in the constellation Vela
HR 3831 A
light curve for IM Velorum (HR 3831), plotted from
TESS data.
[ 1] The 2.852 day period
[ 2] is shown in red.
Observation dataEpoch J2000 Equinox J2000 Constellation Vela HD 83368A Right ascension 09h 36m 25.4255s [ 3] Declination −48° 45′ 04.240″[ 3] Apparent magnitude (V)6.23[ 4] HD 83368B Right ascension 09h 36m 25.3660s [ 5] Declination −48° 45′ 07.505″[ 5] Apparent magnitude (V)10.31[ 4] Characteristics HD 83368A Spectral type A8V[ 6] Variable type Rapidly oscillating Ap HD 83368B Spectral type F9V[ 7] Astrometry HD 83368A Proper motion (μ)RA: -8.16± 0.03mas /yr [ 3] Dec.: -18.85± 0.03mas /yr [ 3] Parallax (π)14.01± 0.03 mas [ 3] Distance 232.8 ± 0.5 ly pc ) HD 83368B Radial velocity (Rv )-4.0± 0.3[ 5] km/s Proper motion (μ)RA: -9.41± 0.19 mas /yr [ 5] Dec.: -14.00± 0.17 mas /yr [ 5] Parallax (π)14.31 ± 0.15 mas [ 5] Distance 228 ± 2 ly pc ) Details Aa Mass 1.78+0.12 −0.17 [ 8] M ☉ Radius 2.003[ 9] R ☉ Luminosity (bolometric) 12.33[ 9] L ☉ Surface gravity (log g )4.2[ 9] cgs Temperature 7650[ 9] K Rotation 2.851976± 0.00003d [ 9] Rotational velocity (v sin i )33.8± 1.0[ 8] Age 0.93+0.42 −0.34 [ 8] Gyr Ab Mass 0.64[ 10] M ☉ Radius 0.60[ 10] R ☉ Temperature 4,175[ 10] K B Mass 1[ 10] M ☉ Other designations CD −48 4831HD 83368HIP 47145HR 3831SAO 221339GSC 08176-00283IM Vel [ 6] HD 83368A :2MASS J09362541-4845042, TYC 8176-283-1HD 83368B :2MASS J09362537-4845072, Gaia DR2 5410092611662456704, TYC 8176-2818-1Database references SIMBAD data
HR 3831 , also known as HD 83368, is a triplestar system in the southernconstellation ofVela at a distance of 233 light years . This object is barely visible to thenaked eye as a dim, blue star with anapparent visual magnitude of 6.232. It is approaching the Earth with a heliocentricradial velocity of 4.0± 0.3 km/s.[ 5]
The star system is a hierarchical binary, made up of an inner and an outer pair. The inner pair has an orbital separation of 13astronomical units , and contain the primary star, HR 3831 Aa, and the secondary HR 3831 Ab. The outer component have a 214 AUprojected separation from the inner pair.[ 10] rapidly oscillating Ap type. It has a single yet strongly distorted dipole pulsation mode with a frequency of 1427 μHz.[ 11] chemically peculiar , exhibiting spots of enhanced concentrations of lithium, europium and oxygen.[ 9]
The star's variability was discovered by Pierre Renson, and announced in 1977.[ 12] variable star designation , IM Velorum, in 1981.[ 13]
^ "MAST: Barbara A. Mikulski Archive for Space Telescopes" . Space Telescope Science Institute. Retrieved27 September 2024 .^ Kurtz, D. W.; van Wyk, F; Roberts, G.; Marang, F.; Handler, G.; Medupe, R.; Kilkenny, D. (May 1997)."Frequency variability in the rapidly oscillating AP star HR 3831: three more years of monitoring" .Monthly Notices of the Royal Astronomical Society .287 (1):69– 78.Bibcode :1997MNRAS.287...69K .doi :10.1093/mnras/287.1.69 ^a b c d 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 .^a b 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.Bibcode :2002A&A...384..180F .doi :10.1051/0004-6361:20011822 . ^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 .^a b "HD 83368" .SIMBAD Centre de données astronomiques de Strasbourg . RetrievedJune 30, 2021 .^ "HD 83368B" .SIMBAD Centre de données astronomiques de Strasbourg . RetrievedJune 30, 2021 .^a b c Sikora, J.; Wade, G. A.; Power, J.; Neiner, C. (2019), "A volume-limited survey of MCP stars within 100 pc – I. Fundamental parameters and chemical abundances",Monthly Notices of the Royal Astronomical Society ,483 (2):2300– 2324,arXiv :1811.05633 Bibcode :2019MNRAS.483.2300S ,doi :10.1093/mnras/sty3105 ^a b c d e f Kochukhov, O. (2005), "Pulsational line profile variation of the roAp star HR 3831",Astronomy & Astrophysics ,446 (3):1051– 1070,arXiv :astro-ph/0509446 doi :10.1051/0004-6361:20053345 ,S2CID 13102520 ^a b c d e Waisberg, Idel; Klein, Ygal; Katz, Boaz (April 2023)."Discovery of a 0.64M ☉ , 13.4 au Companion to the roAp Star HIP 47145 = HR 3831 = IM Vel*" .Research Notes of the AAS .7 (4): 66.doi :10.3847/2515-5172/accb5d ISSN 2515-5172 . ^ Bigot, L.; Kurtz, D. W. (2011), "Theoretical light curves of dipole oscillations in roAp stars",Astronomy & Astrophysics ,536 : A73,arXiv :1110.0988 Bibcode :2011A&A...536A..73B ,doi :10.1051/0004-6361/201116981 ,S2CID 54532822 ^ Renson, P. (20 May 1977)."Periodicite d'Etoiles Ap Australes" (PDF) .Invormal Bulletin on Variable Stars .1280 : 1.Bibcode :1977IBVS.1280....1R . Retrieved20 October 2024 . ^ Kholopov, P. N.; Samus, N. N.; Kukarkina, N. P.; Medvedeva, G. I.; Perova, N. B. (February 1981)."65th Name-List of Variable Stars" (PDF) .Information Bulletin on Variable Stars .1921 : 1.Bibcode :1981IBVS.1921....1K . Retrieved20 October 2024 .
