HR 3562

HR 3562
Location of HR 3562 (circled)
Observation data
Epoch J2000[1]      Equinox J2000[1]
Constellation Vela
HR 3562A
Right ascension 08h 55m 19.20215s
Declination −45° 02′ 30.0241″
Apparent magnitude (V) +6.26[2]
HR 3562B
Right ascension 08h 55m 21.6s[3]
Declination −45° 02′ 52″[3]
Apparent magnitude (V) +12.639[4]
Characteristics
HR 3562A
Spectral type A3IV[5]
U−B color index −0.63[2]
B−V color index −0.16[2]
J−H color index −0.121[6]
J−K color index −0.132[6]
Variable type Slowly pulsating B-type star
Astrometry
HD 3562A
Radial velocity (Rv)22.0±3.3[7] km/s
Proper motion (μ) RA: -13.091[8] mas/yr
Dec.: 7.601[8] mas/yr
Parallax (π)2.6833 ± 0.0455 mas[8]
Distance1,220 ± 20 ly
(373 ± 6 pc)
Absolute magnitude (MV)−2.55[4]
HR 3562B
Absolute magnitude (MV)5.22[4]
Orbit[4]
PrimaryHR 3562A
CompanionHR 3562B
Semi-major axis (a)35.0"
(10024 AU)
Details[4]
HR 3562A
Mass5.644±0.282[5] M☉
Radius5.648±0.282[5] R☉
Luminosity832 L☉
Surface gravity (log g)3.67 or 4.01 cgs
Temperature16,982 K
Rotational velocity (v sin i)5[9] km/s
Age36-38 Myr
HR 3562B
Luminosity0.64[a] L☉
Temperature5,613 K
Age50-110 Myr
Other designations
WDS 08553-4503AB
HR 3562A: IY Velorum, CD−44° 4951, CPD−44° 3226, Gaia DR3 5331355759365786368, GC 12349, HD 76566, HIP 43807, HR 3562A, SAO 220664, PPM 313785, WDS J08553-4503A, TIC 30125083, TYC 8152-139-1, GSC 08152-00139, 2MASS J08551918-4502298[1]
HR 3562B: CD−44° 4951B, CPD−44° 3226B, HD 76566B, WDS J08553-4503B[3]
Database references
SIMBADA
B

HR 3562 (HD 76566) is a visual binary consisting of a bluish-white hued variable star and a Sun-like secondary star in the southern constellation of Vela. It has the variable-star designation IY Velorum (abbreviated to IY Vel). With an apparent magnitude of 6.26, the brighter primary is near the limit for naked eye visibility. The fainter companion has an apparent magnitude of 12.639[4] and can be observed with a telescope with an aperture of 76 mm or wider.[10] It is located approximately 373 parsecs (1,220 ly) distant according to Gaia EDR3 parallax measurements, and is receding away from the Solar System at a heliocentric radial velocity of 22.0 km/s.

HR 3562A

This is a hot, luminous B-type subgiant (spectral type B3IV) with a mass of 5.644 M☉ and a radius of 5.648 R☉.[5] It radiates 832 times the luminosity of the Sun from its photosphere at an effective temperature of 16,982 K (16,709 °C; 30,108 °F), almost three times hotter than the Sun (5,772 K). It is thought to be very young at around 36-38 million years old.[4]

A light curve for IY Velorum, plotted from TESS data.[11] The mean 2.22 day period is marked in red.

In 1982, Burki et al. reported that the star showed pulsations with multiple periods, namely 1.97 days, 1.73 days, and 1.66 days, all with amplitudes of several mmag that produce a combined peak-to-peak amplitude of about 0.04 mag. As such, they categorized the star as a multiperiodic slowly pulsating B-type star (SPB).[12] In 1986, however, Balona & Laing were only able to confirm one major period of 2.22 days. Due to the small projected rotational velocity, they classified it as a rotating ellipsoidal variable instead, which would have been indicative of a close binary with an orbital period of 4.44 days.[9] Further observations were conducted by Balona, who, in 1994, changed his position and concluded that the star was indeed a SPB, having discovered that the 2.22 day period he previously found was actually the mean of three distinct periods at 1.9566 days, 2.1072 days, and 2.4563 days. It shows similarities to HR 2680, another SPB.[13]

HR 3562B

HR 3562 was first discovered to be a double star by John Herschel in 1836.[14] In 2001, it was confirmed that this was a physical binary system rather than an optical double i.e., a pair of unrelated stars closely aligned by chance. The pair are spaced 10,024 AU (0.15850 ly) apart, based on the separation of 35.0 arcseconds. This secondary is a post-T Tauri star, currently in the main sequence, with a Sun-like mass (0.98-1.01 M☉) and a slightly cooler temperature of 5,613 K (5,340 °C; 9,644 °F), emitting 64% the Sun's luminosity. The star is aged about 50-110 million years.[4]

Footnotes

  1. ^ Calculated from absolute magnitude.

References

  1. ^ a b "HD 76566". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 9 January 2025.
  2. ^ a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ a b c "HD 76566B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 9 January 2025.
  4. ^ a b c d e f g h Gerbaldi, M.; Faraggiana, R.; Balin, N. (2001). "Binary systems with post-T Tauri secondaries" (PDF). Astronomy & Astrophysics. 379 (1): 162–184. doi:10.1051/0004-6361:20011298. ISSN 0004-6361. Retrieved 7 January 2025.
  5. ^ a b c d Kervella, Pierre; Arenou, Frédéric; Mignard, François; Thévenin, Frédéric (2019). "Stellar and substellar companions of nearby stars from Gaia DR2: Binarity from proper motion anomaly" (PDF). Astronomy & Astrophysics. 623: A72. doi:10.1051/0004-6361/201834371. ISSN 0004-6361. Retrieved 7 January 2025. Record for this source at VizieR.
  6. ^ a b Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  7. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. doi:10.1134/S1063773706110065. ISSN 1063-7737. Retrieved 9 January 2025.
  8. ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  9. ^ a b Balona, L. A.; Laing, J. D. (1 December 1986). "HR 3562 and 3600: two short-period B-type variables". Monthly Notices of the Royal Astronomical Society. 223 (3): 621–627. doi:10.1093/mnras/223.3.621. ISSN 0035-8711.
  10. ^ North, Gerald; James, Nick (2014). Observing Variable Stars, Novae and Supernovae. Cambridge University Press. p. 24. ISBN 978-1-107-63612-5.
  11. ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 9 January 2025.
  12. ^ Burki, G.; Burnet, M.; Magalhaes, A. S.; North, P.; Rufener, F.; Waelkens, C. (19 October 1982). "HR 3562 and HR 3600, Two New Multi-Periodic B-Type Stars". Information Bulletin on Variable Stars. 2211 (1). Konkoly Observatory, Budapest: International Astronomical Union. Bibcode:1982IBVS.2211....1B.
  13. ^ Balona, L. A. (15 October 1994). "The 53 Per stars HR 3562 and HR 3600" (PDF). Monthly Notices of the Royal Astronomical Society. 270 (4): 914–920. doi:10.1093/mnras/270.4.914. ISSN 0035-8711. Retrieved 7 January 2025.
  14. ^ 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): 3466–3471. doi:10.1086/323920. Retrieved 8 January 2025. Access to this catalog at astro.gsu.edu (right ascension 6h-11h). See references here.