 A blue band light curve for 8 Aquilae, adapted from Machado et al. (2007) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 18 51 22.15821 |
| Declination | −03° 19′ 04.2851″ |
| Apparent magnitude (V) | 6.08 |
| Characteristics | |
| Spectral type | F0 IV or F2 III |
| U−B color index | +0.06 |
| B−V color index | +0.299±0.007 |
| Variable type | δ Sct |
| Astrometry | |
| Radial velocity (Rv) | +11.8 km/s |
| Proper motion (μ) | RA: +2.019 mas/yr Dec.: −21.411 mas/yr |
| Parallax (π) | 12.0549 ± 0.0268 mas |
| Distance | 270.6 ± 0.6 ly (83.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 1.27 |
| Details | |
| Mass | 1.60 M☉ |
| Radius | 3.0 R☉ |
| Luminosity | 18.89 L☉ |
| Surface gravity (log g) | 3.88±0.14 cgs |
| Temperature | 7,395±251 K |
| Metallicity | 0.14 dex |
| Rotational velocity (v sin i) | 105 km/s |
| Age | 959 Myr |
| Other designations | |
| 8 Aql, V1729 Aql, BD−03°4392, FK5 3500, HD 174589, HIP 92524, HR 7101, SAO 142706 | |
| Database references | |
| SIMBAD | data |
8 Aquilae is a star in the equatorial constellation of Aquila, located 271 light years away from the Sun. 8 Aquilae is the Flamsteed designation. It can be viewed with the naked eye in good seeing conditions, appearing as a dim, yellow-white hued star with an apparent visual magnitude of 6.08. The star is moving further from the Earth with a heliocentric radial velocity of +12 km/s.
Abt and Morrell (1995) found a stellar classification of F0 IV for this star, suggesting it is an F-type subgiant. In their 2010 study, Fox Machado et al. assigned a class of F2 III, which matches an evolved giant star. Despite the spectral classifications, evolutionary models place the star towards the end of its main sequence life, with an age of about a billion years.
Lester Fox Machado et al. discovered that 8 Aquilae is a variable star during observations conducted in 2003, and published in 2007. It is a Delta Scuti variable with at least three overlapping pulsation frequencies, although the total amplitude of its brightness variations is only about 0.02 magnitudes. It has a relatively high rotation rate, showing a projected rotational velocity of 105 km/s. It has 1.6 times the mass of the Sun and is radiating 19 times the Sun's luminosity from its photosphere at an effective temperature of about 7,395 K.
References
- ^ Machado, L. Fox; Michel, E.; Hernandez, F. Perez; Pena, J. H.; Li, M. A.; Pau, S.; Fernandez, A.; Michel, J. P.; Michel, R.; Pani, A. (August 2007). "Multisite Observations of δ Scuti Stars 7 Aql and 8 Aql (a New δ Scuti Variable): The Twelfth STEPHI Campaign in 2003". The Astronomical Journal. 134 (2): 860–866. arXiv:0706.0576. Bibcode:2007AJ....134..860F. doi:10.1086/520062. S2CID 15349358.
- ^ 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 at VizieR.
- ^ Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1, Bibcode:1999VeARI..35....1W.
- ^ Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
- ^ Fox Machado, L.; et al. (July 2010), "Strömgren photometry and spectroscopy of the δ Scuti stars 7 Aql and 8 Aql", New Astronomy, 15 (5): 397–402, arXiv:0912.2808, Bibcode:2010NewA...15..397F, doi:10.1016/j.newast.2009.11.006, S2CID 119241648.
- Cousins, A. W. J. (1965), "Photometric Data for Stars in the Equatorial Zone (Eighth List)", Monthly Notes of the Astronomical Society of Southern Africa, 24: 120, Bibcode:1965MNSSA..24..120C.
- ^ 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.
- ^ David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ Royer, F.; et al. (2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i in the northern hemisphere", Astronomy and Astrophysics, 393 (3): 897–911, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943, S2CID 14070763.
- ^ "8 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved April 25, 2019.
External links
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