HD 73752
  | |
| Observation data Epoch J2000[1] Equinox J2000[1] | |
|---|---|
| Constellation | Pyxis |
| Right ascension | 08h 39m 17.89867s |
| Declination | −22° 39′ 42.8283″ |
| Apparent magnitude (V) | 5.17 (combined)[2] |
| Characteristics | |
| Spectral type | (G5IV + unknown) + K0V or GV[3] |
| B−V color index | 0.83[2] |
| J−H color index | 0.456[4] |
| J−K color index | 0.461[4] |
| Astrometry | |
| Radial velocity (Rv) | 52.13 ± 0.22[5] km/s |
| Proper motion (μ) | RA: −240.319[1] mas/yr Dec.: 459.973[1] mas/yr |
| Parallax (π) | 50.9663 ± 0.3068 mas[1] |
| Distance | 64.0 ± 0.4 ly (19.6 ± 0.1 pc) |
| Absolute magnitude (MV) | 3.83 (A), 5.28 (B)[6] |
| Orbit[3] | |
| Primary | HD 73752 Aa |
| Companion | HD 73752 Ab |
| Period (P) | 211.76±0.17 d |
| Semi-major axis (a) | ≥(8.83±0.16)×106 km |
| Eccentricity (e) | 0.210±0.016 |
| Periastron epoch (T) | 56372.6±2.7 |
| Argument of periastron (ω) (secondary) | 142.9±4.9° |
| Orbit[7] | |
| Primary | HD 73752 A |
| Companion | HD 73752 B |
| Period (P) | 127 yr |
| Semi-major axis (a) | 1.69" (34 AU[8]) |
| Eccentricity (e) | 0.32 |
| Inclination (i) | 167° |
| Longitude of the node (Ω) | 211° |
| Periastron epoch (T) | 1986 |
| Argument of periastron (ω) (secondary) | 124° |
| Details[6] | |
| HD 73752 Aa | |
| Mass | 1.21 M☉ |
| Radius | 1.68 R☉ |
| Luminosity | 2.31[a] L☉ |
| Surface gravity (log g) | 4.07 cgs |
| Temperature | 5680 K |
| Metallicity [Fe/H] | 0.32 dex |
| Rotational velocity (v sin i) | 3.3±0.5[9] km/s |
| Age | 7 Gyr |
| HD 73752 B | |
| Mass | 1.04 M☉ |
| Radius | 1.01 R☉ |
| Luminosity | 0.608[a] L☉ |
| Surface gravity (log g) | 4.45 cgs |
| Temperature | 5340 K |
| Other designations | |
| Database references | |
| SIMBAD | HD 73752 |
HD 73752 is a multiple star system located in the southern constellation of Pyxis. With an apparent magnitude of 5.17, it can be faintly seen by the naked eye from Earth as a yellow-hued dot of light. As such, it is listed in the Bright Star Catalogue as HR 3430. It is located at a distance of approximately 64.0 light-years (19.6 parsecs) according to Gaia EDR3 parallax measurements, and is receding at a heliocentric radial velocity of 52.13 km/s.
Physical properties
[edit]The system is roughly seven billion years old, much older than the Solar System (4.568 Gyr[11]), and belongs to the thin disk population of the Milky Way.[6]
The primary star, HD 73752 Aa, is an aging subgiant, a star that has fused all the hydrogen in its core into helium and evolved past the main sequence, with the spectral type G5IV. It is 21% more massive than the Sun, equivalent to a typical F-type main-sequence star with the spectral type F7V,[12] but has expanded to a radius of 1.68 R☉. It radiates 2.31 times the luminosity of the Sun from its photosphere at an effective temperature of 5,680 K (5,410 °C; 9,760 °F). The entire system is very metal-rich with a metallicity of +0.32, which equates to an iron abundance 100.32 ≈ 2.1 times that of the Sun. A low-mass close companion, Ab, orbits Aa in a 211.76-day (0.5798-year) orbit, but its precise parameters remain uncertain.[3]
The secondary star, which is in a 127-year binary orbit with the Aa/Ab pair, is a G-type or K-type main-sequence star similar to the Sun in mass and radius, but substantially cooler at 5,340 K (5,070 °C; 9,150 °F). As such, it emits only three-fifths the Sun's luminosity.
Multiplicity
[edit]HD 73752 has been known to be a close visual binary since 1874.[3] As early as 1943, a third unseen component was suspected, though this suggestion of a ~0.1 M☉ object in a 35-year orbit remained inconclusive,[6] and a 1967 study[13] turned up little evidence. Radial velocity variations were observed in 1980[14] and 2006[15] that strongly implied a low-mass object, though the orbital parameters could not be obtained. In 2016, HD 73752 A was finally confirmed to be a spectroscopic binary.[3]
Additionally, another possible companion, 13.7 magnitudes fainter than the primary in the H band, was noticed at a separation of 4".50 in right ascension and 6".02 in declination, but this has not been followed up on.[16]
Circumstellar disc
[edit]HD 73752 has been referred to as a "Vega-like star," a star that exhibits excess infrared emission due to an optically thin dusty circumstellar disc containing almost no gas. Because this star is past the main sequence, the process in which the emissions are produced may diverge from that of younger such stars e.g., Epsilon Eridani, HD 53143, HD 69830, and HD 98800.[17] In 2012, a debris disc was detected at a distance of 21 AU from the primary, an unstable position close to the secondary star's orbit at 34 AU.[8] Despite this, a 2019 study did not find any significant infrared excess at a wavelength of 70 μm.[18]
See also
[edit]- 70 Virginis: a G-type subgiant similar to HD 73752 Aa.
- List of star systems within 60–65 light-years
Notes
[edit]- ^ a b Calculated from absolute magnitude.[6]
References
[edit]- ^ a b c d 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.
- ^ a b Zacharias, N.; et al. (14 January 2013). "THE FOURTH US NAVAL OBSERVATORY CCD ASTROGRAPH CATALOG (UCAC4)". The Astronomical Journal. 145 (2): 44. doi:10.1088/0004-6256/145/2/44. ISSN 0004-6256. Retrieved 25 December 2024.
- ^ a b c d e Willmarth, Daryl W.; et al. (1 August 2016). "SPECTROSCOPIC ORBITS FOR 15 LATE-TYPE STARS". The Astronomical Journal. 152 (2): 46. doi:10.3847/0004-6256/152/2/46. ISSN 0004-6256.
- ^ a b Cutri, Roc M.; et al. (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.
- ^ Maldonado, J.; et al. (2010). "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups". Astronomy and Astrophysics. 521: A12. doi:10.1051/0004-6361/201014948. ISSN 0004-6361. Retrieved 25 December 2024.
- ^ a b c d e Fuhrmann, K.; et al. (11 March 2011). "BESO échelle spectroscopy of solar-type stars at Cerro Armazones: BESO échelle spectroscopy" (PDF). Monthly Notices of the Royal Astronomical Society. 411 (4): 2311–2318. doi:10.1111/j.1365-2966.2010.17850.x. Retrieved 24 December 2024.
- ^ Söderhjelm, Staffan (January 1999). "Visual Binary Orbits and Masses Post-Hipparcos". Astronomy & Astrophysics. 341: 121–140. Bibcode:1999A&A...341..121S.
- ^ a b Rodriguez, David R.; et al. (1 February 2012). "BINARIES AMONG DEBRIS DISK STARS". The Astrophysical Journal. 745 (2): 147. doi:10.1088/0004-637X/745/2/147. ISSN 0004-637X. Retrieved 24 December 2024.
- ^ Weise, P.; et al. (2010). "Rotational velocities of nearby young stars" (PDF). Astronomy and Astrophysics. 517: A88. doi:10.1051/0004-6361/201014453. ISSN 0004-6361. Retrieved 24 December 2024.
- ^ "HD 73752". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 25 December 2024.
- ^ Bouvier, A.; Wadhwa, M. (2010). "The age of the Solar System redefined by the oldest Pb–Pb age of a meteoritic inclusion". Nature Geoscience. 3 (9): 637–641. Bibcode:2010NatGe...3..637B. doi:10.1038/NGEO941. S2CID 56092512.
- ^ Mamajek, Eric (16 April 2022). "A Modern Mean Dwarf Stellar Color and Effective Temperature Sequence". Retrieved 11 November 2024.
- ^ Newburg, J. L. (1967). "The Orbit of β 208 AB, ADS 6914, HD 73752, with Some Notes on the System". Monthly Notes of the Astronomical Society of Southern Africa. 26: 110–113. Bibcode:1967MNSSA..26..110N.
- ^ Abt, H. A.; Levy, S. G.; Sanwal, N. B. (1980). "Visual multiples. V - Radial velocities of 160 systems". The Astrophysical Journal Supplement Series. 43: 549. doi:10.1086/190682. ISSN 0067-0049.
- ^ Abt, Helmut A.; et al. (2006). "The Secondaries of Solar‐Type Primaries. I. The Radial Velocities". The Astrophysical Journal Supplement Series. 162 (1): 207–226. doi:10.1086/498095. ISSN 0067-0049. Retrieved 24 December 2024.
- ^ Janson, Markus; et al. (26 July 2013). "THE SEEDS DIRECT IMAGING SURVEY FOR PLANETS AND SCATTERED DUST EMISSION IN DEBRIS DISK SYSTEMS". The Astrophysical Journal. 773 (1): 73. doi:10.1088/0004-637X/773/1/73. ISSN 0004-637X. Retrieved 24 December 2024.
- ^ Song, Inseok; et al. (10 April 2000). "Ages of Late Spectral Type Vega-like Stars". The Astrophysical Journal. 533 (1): L41–L44. doi:10.1086/312597. Retrieved 24 December 2024.
- ^ Yelverton, Ben; et al. (21 September 2019). "A statistically significant lack of debris discs in medium separation binary systems". Monthly Notices of the Royal Astronomical Society. 488 (3): 3588–3606. doi:10.1093/mnras/stz1927. ISSN 0035-8711. Retrieved 24 December 2024.
