HD 147379
  | |
| Observation data Epoch J2000[1] Equinox J2000[1] | |
|---|---|
| Constellation | Draco |
| HD 147379A | |
| Right ascension | 16h 16m 42.74635s |
| Declination | +67° 14′ 19.8316″ |
| Apparent magnitude (V) | 8.9[2] |
| HD 147379B | |
| Right ascension | 16h 16m 45.31448s[3] |
| Declination | +67° 15′ 22.4811″[3] |
| Apparent magnitude (V) | 10.69-10.74[4] |
| Characteristics | |
| HD 147379A | |
| Spectral type | M0.0V[2] |
| B−V color index | 1.11[2] |
| J−H color index | 0.643[5] |
| J−K color index | 0.826[5] |
| HD 147379B | |
| Spectral type | M3V[6] |
| J−H color index | 0.608[5] |
| J−K color index | 0.842[5] |
| Variable type | BY Draconis variable[4] |
| Astrometry | |
| HD 147379A | |
| Radial velocity (Rv) | −18.962±0.0011[7] km/s |
| Proper motion (μ) | RA: -497.915[8] mas/yr Dec.: 84.047[8] mas/yr |
| Parallax (π) | 92.8766 ± 0.0146[8] mas |
| Distance | 35.117 ± 0.006 ly (10.767 ± 0.002 pc) |
| HD 147379B | |
| Radial velocity (Rv) | −18.36±0.0008[9] km/s |
| Proper motion (μ) | RA: -483.006[10] mas/yr Dec.: 89.049[10] mas/yr |
| Parallax (π) | 92.8985 ± 0.0160[10] mas |
| Distance | 35.109 ± 0.006 ly (10.764 ± 0.002 pc) |
| Orbit[2] | |
| Primary | HD 147379A |
| Companion | HD 147379B |
| Semi-major axis (a) | 64.4" (693.4 AU) |
| Details[11] | |
| HD 147379A | |
| Mass | 0.58±0.08 M☉ |
| Radius | 0.57±0.06 R☉ |
| Luminosity | 0.1069±0.0153[12] L☉ |
| Surface gravity (log g) | 4.609±0.012[2] cgs |
| Temperature | 4090±50 K |
| Metallicity [Fe/H] | 0.16±0.16 dex |
| HD 147379B | |
| Mass | 0.45±0.02[6] M☉ |
| Radius | 0.460±0.008[6] R☉ |
| Luminosity | 0.02645±0.00645[13] L☉ |
| Surface gravity (log g) | 4.84±0.06[6] cgs |
| Temperature | 3525±31[6] K |
| Metallicity | 0.20±0.10 dex[6] |
| Rotation | 40.4±3.0 d[6] |
| Rotational velocity (v sin i) | 0.50[6] km/s |
| Other designations | |
WDS 08553-4503AB | |
| HD 147379A: IY Velorum, CD−44° 4951, CPD−44° 3226, GC 12349, HD 76566, HIP 43807, HR 3562A, SAO 220664, PPM 313785, WDS J08553-4503A, TYC 8152-139-1, GSC 08152-00139, 2MASS J08551918-4502298[1] | |
| HD 147379B: CD−44° 4951B, CPD−44° 3226B, HD 76566B, WDS J08553-4503B[3] | |
| Database references | |
| SIMBAD | A |
| B | |
HD 147379 (Gliese 617) is a wide visual binary between two red dwarfs in the deep northern constellation of Draco. The two stars are located approximately 35.1 light-years (10.8 pc) distant based on Gaia EDR3 parallax measurements, and approaching the Solar System at heliocentric radial velocities of −18.962 km/s and −18.36 km/s, respectively. The brighter primary star, HD 147379A, has an apparent magnitude of 8.9,[2] too faint to be seen by the naked eye from Earth but visible using binoculars.[14] The dimmer secondary, B, fluctuates in apparent magnitude between 10.69-10.74,[4] making it observable via a telescope with an aperture of 35 mm or larger.[15]
HD 147379A
HD 147379A (HIP 79755) is a red dwarf with a spectral type of M0.0V, about 58% the mass of the Sun and 57% the radius.
Planetary system
In 2018, two teams independently reported the discovery of an exoplanet orbiting HD 147379A, both via the radial-velocity method.[11][12] The planet, commonly referred to as HD 147379 b, has a minimum mass of 21.6 ± 1.1 M⊕, slightly more massive than Neptune (17.147 M⊕[16]). It orbits its host star once every 86.58 days at about a third of the distance from Earth to the Sun, placing it within the conservative habitable zone of the star, where liquid water could exist.[2]
One of the teams that discovered HD 147379 b proposed another candidate planet, this one with a minimum mass of 27 M⊕ and a 500-day period, orbiting at a distance of about 1 AU.[12] However, a 2023 follow-up study did not detect such a signal. Instead, they detected a signal with a 12.3-day period, but discarded it due to the high chance of it being a false positive. Nevertheless, it is highly likely that a second planet exists interior to b's orbit.[2]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥21.6 ± 1.1 M⊕ | 0.3315 ± 0.0024[17] | 86.58 ± 0.14 | 0.0630+0.0470 −0.0380 |
— | — |
HD 147379B
HD 147379B (HIP 79762) is a gravitationally bound companion to HD 147379A at a separation of 64.4 arcseconds, which corresponds to a distance of 693.4 AU.[2]
This is a red dwarf with a spectral type of M3V, about 45% the mass of the Sun and 46% the radius. It has a "partially convective" structure, meaning that the outer convection zone does not reach down to the core,[6] as opposed to "fully convective" stars weighing less than 0.35 M☉ that are convective throughout.[18] It has a high metallicity of [M/H]=0.20±0.10 dex, translating to a roughly 60% excess in elements heavier than hydrogen and helium compared to the Sun. At an effective temperature of 3,525 K (3,252 °C; 5,885 °F),[6] It radiates just 2.6% the luminosity of the Sun from its photosphere.[13] It rotates on its axis once every 40.4 days at a relatively slow projected equatorial velocity of 0.50 km/s.[6]
It has a magnetic field that fluctuated in strength between 36-75 G between 2020-2022, approximately 100 times stronger than Earth's magnetic field (0.22-0.67 G[19]) and similar to those of faster-rotating red dwarfs. The variations in strength are smaller than those seen in fully convective red dwarfs such as Gliese 1151.[6]
In 1994, the star was reported to have a high likelihood (99%) of exhibiting long-term variability, albeit the author noted that this may be suspect.[20] It was formally classified as a BY Draconis variable in 1997, receiving the variable-star designation EW Draconis.[4]
References
- ↑ 1.0 1.1 Cite error: Invalid
<ref>tag; no text was provided for refs namedSIMBAD - ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 Stalport, M.; Cretignier, M.; Udry, S.; et al. (2023). "A review of planetary systems around HD 99492, HD 147379, and HD 190007 with HARPS-N" (PDF). Astronomy & Astrophysics. 678: A90. doi:10.1051/0004-6361/202346887. ISSN 0004-6361. Retrieved 2025-01-02.
- ↑ 3.0 3.1 3.2 Cite error: Invalid
<ref>tag; no text was provided for refs namedSIMBAD_B - ↑ 4.0 4.1 4.2 4.3 Kazarovets, E. V.; Samus, N. N. (23 April 1997). "The 73rd Name-List of Variable Stars". Information Bulletin on Variable Stars. 4471: 1–45. Bibcode:1997IBVS.4471....1K.
- ↑ 5.0 5.1 5.2 5.3 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.
- ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 Lehmann, L T; Donati, J-F; Fouqué, P; et al. (2023-11-09). "SPIRou reveals unusually strong magnetic fields of slowly rotating M dwarfs" (PDF). Monthly Notices of the Royal Astronomical Society. 527 (2): 4330–4352. doi:10.1093/mnras/stad3472. ISSN 0035-8711. Retrieved 2025-01-16.
- ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedDR2 - ↑ 8.0 8.1 8.2 Cite error: Invalid
<ref>tag; no text was provided for refs namedEDR3 - ↑ Fouqué, Pascal; Moutou, Claire; Malo, Lison; Martioli, Eder; Lim, Olivia; Rajpurohit, Arvind; Artigau, Etienne; Delfosse, Xavier; Donati, Jean-François; Forveille, Thierry; Morin, Julien; Allard, France; Delage, Raphaël; Doyon, René; Hébrard, Elodie; Neves, Vasco (2018-04-01). "SPIRou Input Catalogue: global properties of 440 M dwarfs observed with ESPaDOnS at CFHT". Monthly Notices of the Royal Astronomical Society. 475 (2): 1960–1986. doi:10.1093/mnras/stx3246. ISSN 0035-8711. Retrieved 2025-01-17.
- ↑ 10.0 10.1 10.2 Cite error: Invalid
<ref>tag; no text was provided for refs namedEDR3_B - ↑ 11.0 11.1 Reiners, A.; Ribas, I.; Zechmeister, M.; et al. (2018). "The CARMENES search for exoplanets around M dwarfs: HD147379 b: A nearby Neptune in the temperate zone of an early-M dwarf" (PDF). Astronomy & Astrophysics. 609: L5. doi:10.1051/0004-6361/201732165. ISSN 0004-6361. Retrieved 2025-01-02.
- ↑ 12.0 12.1 12.2 Hobson, M. J.; Díaz, R. F.; Delfosse, X.; et al. (2018). "The SOPHIE search for northern extrasolar planets: XIII. Two planets around M-dwarfs Gl617A and Gl96" (PDF). Astronomy & Astrophysics. 618: A103. doi:10.1051/0004-6361/201832732. ISSN 0004-6361. Retrieved 2025-01-02.
- ↑ 13.0 13.1 Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin; Torres, Guillermo; Pepper, Joshua; Lee, Nathan De; Collins, Kevin; Latham, David W.; Muirhead, Philip S.; Chittidi, Jay; Rojas-Ayala, Bárbara; Fleming, Scott W.; Rose, Mark E.; Tenenbaum, Peter; Ting, Eric B.; Kane, Stephen R.; Barclay, Thomas; Bean, Jacob L.; Brassuer, C. E.; Charbonneau, David; Ge, Jian; Lissauer, Jack J.; Mann, Andrew W.; McLean, Brian; Mullally, Susan; Narita, Norio; Plavchan, Peter; Ricker, George R.; Sasselov, Dimitar; Seager, S.; Sharma, Sanjib; Shiao, Bernie; Sozzetti, Alessandro; Stello, Dennis; Vanderspek, Roland; Wallace, Geoff; Winn, Joshua N. (2019-10-01). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
- ↑ Zarenski, Ed (2004). "Limiting Magnitude in Binoculars" (PDF). Cloudy Nights. Archived from the original (PDF) on 21 July 2011. Retrieved 6 May 2011. Unknown parameter
|url-status=ignored (help) - ↑ North, Gerald; James, Nick (2014). Observing Variable Stars, Novae and Supernovae. Cambridge University Press. p. 24. ISBN 978-1-107-63612-5. Search this book on
- ↑ Williams, David R. (1 September 2004). "Neptune Fact Sheet". NASA. Archived from the original on 1 July 2010. Retrieved 14 August 2007. Unknown parameter
|url-status=ignored (help) - ↑ Rosenthal, Lee J.; Fulton, Benjamin J.; Hirsch, Lea A.; et al. (2021-07-01). "The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades". The Astrophysical Journal Supplement Series. 255 (1): 8. doi:10.3847/1538-4365/abe23c. ISSN 0067-0049.
- ↑ Reiners, Ansgar; Basri, Gibor (March 2009). "On the magnetic topology of partially and fully convective stars". Astronomy and Astrophysics. 496 (3): 787–790. arXiv:0901.1659. Bibcode:2009A&A...496..787R. doi:10.1051/0004-6361:200811450. Unknown parameter
|s2cid=ignored (help) - ↑ "An Overview of the Earth's Magnetic Field". www.geomag.bgs.ac.uk. Retrieved 2024-03-02.
- ↑ Weis, Edward W. (1994). "Long term variability in dwarf M stars". The Astronomical Journal. 107: 1135. doi:10.1086/116925.
- Pepper, Joshua (2018-01-01). "Rotational Period Measurement of Planet Host HD 147379". Research Notes of the AAS. 2 (1): 14. doi:10.3847/2515-5172/aaa842. ISSN 2515-5172.
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