Gamma Doradus variable explained
Gamma Doradus variables are variable stars which display variations in luminosity due to non-radial pulsations of their surface. The stars are typically young, early F or late A type main sequence stars, and typical brightness fluctuations are 0.1 magnitudes with periods on the order of one day. This class of variable stars is relatively new, having been first characterized in the second half of the 1990s, and details on the underlying physical cause of the variations remains under investigation.
The star 9 Aurigae was first noticed to be variable in 1990. However, none of the currently-accepted explanations were adequate: it pulsated too slowly and was outside of the Delta Scuti instability strip, and there was no evidence for any eclipsing material, although Gamma Doradus and HD 96008 were noted to be similar.[1] These three stars, as well as HD 224638, were soon hypothesized to belong to a new class of variable stars in which variability was produced by g-mode pulsations rather than the p-mode pulsations of Delta Scuti variables.[2] HD 224945 and HD 164615 were noticed to be similar as well, while HD 96008 was ruled out on the basis of its more regular period.[3] Eclipses and starspots were soon ruled out as the cause of the Gamma Doradus' variability,[4] and the variability of 9 Aurigae was confirmed to be caused by g-mode pulsations a year later, thus confirming the stars as the prototypes of a new class of variable stars.[5] Over ten more candidates were quickly found,[6] and the discoverers dubbed the group the Gamma Doradus stars, after the brightest member and the first member found to be variable.[7]
List
| Designation (name)[8] | Constellation | Discovery | Maximum Apparent magnitude (mV) | Minimum Apparent magnitude (mV)[9] | Period (days) | Spectral class | Comment |
|---|
HD 8801 A
(V529 And) | Andromeda | Henry & Fekel (2005)[10] | 6m.48
(Hipparcos) | 6m.51
(Hipparcos) | 0.40331 | A7Vm | First discovered hybrid Gamma Doradus/Delta Scuti variable |
| V872 Ara[11] | Ara | Aerts et al. (1998) | 6m.37
(Hipparcos) | 6m.39
(Hipparcos) | 0.4266 | A9V | |
| 9 Aur A | Auriga | Krisciunas (1993) | 4m.93 | 5m.50 | 1.2582 | F2V | One of the original stars classified |
| 17 CVn | Canes Venatici | Henry et al. (2011) | 5m.91 | | 0.8862 | F0:V | Spectroscopic binary
- unclear which component is variable
|
HD 108100
(DD CVn) | Canes Venatici | Breger et al. (1996)[12] | 7m.15 | | 0.7541 | F2V | |
| V350 CMa A | Canis Major | Eyer & Aerts (2000)[13] | 6m.18 | 6m.27 | 0.7750
10.959 | F2V | Has two distinct periods |
| V1026 Cen | Centaurus | Aerts et al. (1998) | 9m.33
(Hipparcos) | 9m.38
(Hipparcos) | 1.1857 | A3:m | |
| HD 17163 | Cetus | Henry et al. (2011) | 6m.04 | | 0.42351 | F1V | |
HD 14940
(EP Cet) | Cetus | Aerts et al. (1998) | 6m.74 | 6m.77 | 0.5004 | F0IV/V | |
| 43 Cyg | Cygnus | Henry et al. (2005)[14] | 5m.75
(Hipparcos) | 5m.84
(Hipparcos) | 0.79955 | F0V | |
| γ Dor | Dorado | Krisciunas (1993) | 4m.23 | 4m.27 | 0.7570 | F1V | One of the original stars classified |
| 8 Dra | Draco | Aerts et al. (1998) | 5m.26
(Hipparcos) | 5m.34
(Hipparcos) | 0.42450 | F1VmA7(n) | |
| DI Gru | Grus | Aerts et al. (1998) | 8m.68 | 8m.76 | 0.8668 | F3IV | |
| V1325 Her | Hercules | Kaye et al. (1998)[15] | 6m.38 | | 0.4210 | F0V | |
| 80 Leo | Leo | Henry & Fekel (2002)[16] | 6m.34 | 6m.37 | 0.45286 | F3IV | |
HD 40745
(AC Lep) | Lepus | Aerts et al. (1998) | 6m.28
(Hipparcos) | 6m.30
(Hipparcos) | 0.82427 | F2IV | |
| HD 69682 | Lynx | Henry et al. (2011) | 6m.50 | | 0.53189 | A9V | |
| DO Lyn | Lynx | Kaye et al. (1999)[17] | 7m.17 | | 0.62447 | F0V | |
| HD 50747[18] | Monoceros | Dolez et al. (2009) | 5m.45 | | 4.865
0.956 | A4IV | Triple star; unknown which component is variable |
| HD 49434 | Monoceros | Bruntt et al. (2002)[19] | 5m.75 | | 0.57644 | F1V | Hybrid Gamma Doradus/Delta Scuti variable[20] |
| HD 41547 A | Monoceros | Henry et al. (2007)[21] | 5m.87 | | 0.81123 | F4V | |
α Oph[22]
(Rasalhague) | Ophiuchus | Monnier et al. (2010) | 2m.08 | | 0.5850 | A5IV | Hybrid Gamma Doradus/Delta Scuti variable |
| 73 Oph A | Ophiuchus | Fekel & Henry (2003)[23] | 6m.11 (B) | | 0.61439 | F0V+G1V | |
HD 164615
(V2118 Oph) | Ophiuchus | Mantegazza et al. (1994) | 7m.02 | 7m.09 | 0.8117 | F2IV | One of the original stars classified |
| V2502 Oph | Ophiuchus | Aerts et al. (1998) | 6m.57 | 6m.67 | 1.307 | F2V | |
| HD 38309 Aa | Orion | Henry et al. (2011) | 6m.09 | | 0.37703 | F0III:n | |
| NZ Peg | Pegasus | Henry et al. (2001)[24] | 5m.83
(Hipparcos) | 5m.86
(Hipparcos) | 0.41113 | F2V | |
HR 8799
(V342 Peg) | Pegasus | Rodriguez & Zerbi (1995)[25] | 6m.00
(Hipparcos) | 6m.06
(Hipparcos) | 0.5053 | A5V | Lambda Boötis star and Vega-like star[26] |
| V372 Peg | Pegasus | Kaye et al. (1998) | 6m.53 (B) | | 2.594821 | F3V | |
| 39 Peg | Pegasus | Henry et al. (2005) | 6m.43 | 6m.53 | 0.75574 | F1V | |
HD 224638
(BT Psc) | Pisces | Krisciunas (1993) | 7m.8 (B) | | 1.2323 | F0V | One of the original stars classified |
HD 224945
(BU Psc) | Pisces | Mantegazza et al. (1994) | 6m.93 | | 0.5432 | A9V | One of the original stars classified |
| QW Pup | Puppis | Poretti et al. (1997)[27] | 4m.47 | 4m.50 | 0.9584 | F0IV/V | |
| ι TrA A | Triangulum Australe | Aerts et al. (1998) | 5m.30
(Hipparcos) | 5m.42
(Hipparcos) | 1.4556 | F4IV | |
| EE Tuc | Tucana | Aerts et al. (1998) | 6m.72
(Hipparcos) | 6m.82
(Hipparcos) | 0.6935 | F2IV | |
| V349 Tel | Telescopium | Aerts et al. (1998) | 7m.60
(Hipparcos) | 7m.73
(Hipparcos) | 0.6953 | F0V | |
| KO UMa | Ursa Major | Kaye et al. (1999) | 7m.18 | | 0.7691 | F2V | |
| UY UMi | Ursa Minor | Aerts et al. (1998) | 6m.30
(Hipparcos) | 6m.38
(Hipparcos) | 0.7237 | F2V | |
| VX UMi | Ursa Minor | Henry et al. (2001) | 6m.48 (B) | | 0.34510 | A9V |
| ε1 Lyr B | Lyrae | Peretto I., Lora S., Peretto G., Furlato G., Barbieri M. - MarSEC (2022)[28] | 6m.00 V (0.032) TESS | | 0.415 | F0V | |
Notes and References
- 1993MNRAS.263..781K. astro-ph/9304008 . The 9-AURIGAE System . Monthly Notices of the Royal Astronomical Society . 263 . 3 . 781 . Krisciunas . K. . Aspin . C. . Geballe . T. R. . Akazawa . H. . Claver . C. F. . Guinan . E. F. . Landis . H. J. . Luedeke . K. D. . Ohkura . N. . Ohshima . O. . Skillman . D. R. . 1993 . 10.1093/mnras/263.3.781 . free .
- 1993AAS...183.8402K. A new class of pulsating stars. American Astronomical Society. 183.
- 84.02
. Krisciunas. K.. 1993.
- 1994MNRAS.270..439M. Unusual Variability among Early F-Type Stars - HD224638 and HD224945. Monthly Notices of the Royal Astronomical Society. 270. 2. 439. Mantegazza. L.. Poretti. E.. Zerbi. F. M.. 1994. 10.1093/mnras/270.2.439. free.
- 1994MNRAS.270..905B. Gamma-Doradus - Evidence for a New Class of Pulsating Star. Monthly Notices of the Royal Astronomical Society. 270. 4. 905. Balona. L. A.. Krisciunas. K.. Cousins. A. W. J.. 1994. 10.1093/mnras/270.4.905. free.
- 1995MNRAS.273..662K. astro-ph/9407094 . 9 Aurigae: Strong evidence for non-radial pulsations . Monthly Notices of the Royal Astronomical Society . 273 . 3 . 662 . Krisciunas . K. . Griffin . R. F. . Guinan . E. F. . Luedeke . K. D. . McCook . G. P. . 1995 . 10.1093/mnras/273.3.662 . free .
- 1995IBVS.4195....1K. A List of Variable Stars Similar to gamma Dor. Information Bulletin on Variable Stars. 4195. 1. Krisciunas. K.. Handler. G.. 1995.
- 1995DSSN....9...17K. What is known and not known about Gamma Doradus stars. Delta Scuti Star Newsletter. 9. 17. Krisciunas. K.. 1995.
- Henry. Gregory W.. Fekel. Francis C.. Henry. Stephen M.. A VOLUME-LIMITED PHOTOMETRIC SURVEY OF 114 γ DORADUS CANDIDATES. The Astronomical Journal. 142. 2. 2011. 39. 2011AJ....142...39H. 10.1088/0004-6256/142/2/39. 1105.4161 .
- 2009yCat....102025S. VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013). VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. 02025. Samus. N. N.. Durlevich. O. V.. 2009. etal.
- Henry. Gregory W.. Fekel. Francis C.. HD 8801: A Unique Single Am Star with γ Doradus and δ Scuti Pulsations. The Astronomical Journal. 129. 4. 2005. 2026–2033. 2005AJ....129.2026H. 10.1086/428373. free.
- 1998A&A...337..790A. The discovery of new gamma Doradus stars from the HIPPARCOS mission. Astronomy and Astrophysics. 337. 790. Aerts. C.. Eyer. L.. Kestens. E.. 1998.
- 1996DSSN...10...24B. A new Gamma Doradus star, HD 108100. Delta Scuti Star Newsletter. 10. 24. Breger. M.. Handler. G.. Garrido. R.. Audard. N.. Beichbuchner. F.. Zima. W.. Paparo. M.. Li. Z.. Jiang. S.. Liu. Z.. Zhou. A.. Pikall. H.. Stankov. A.. Guzik. J. A.. Sperl. M.. Krzesinski. J.. Ogloza. W.. Pajdosz. G.. Zola. S.. Serkowitsch. E.. Reegen. P.. Rumpf. T.. Schmalwieser. A.. 1996.
- 2000A&A...361..201E. astro-ph/0011061 . A search for new gamma Doradus stars in the Geneva photometric database . Astronomy and Astrophysics . 361 . 201 . Eyer . L. . Aerts . C. . 2000 .
- Henry. Gregory W.. Fekel. Francis C.. Henry. Stephen M.. Eleven New γ Doradus Stars. The Astronomical Journal. 129. 6. 2005. 2815–2830. 2005AJ....129.2815H. 10.1086/429876. free.
- 1998ASPC..135..497K. Recent Periodic Variations in Three Gamma Doradus Variables. A Half Century of Stellar Pulsation Interpretation: A Tribute to Arthur N. Cox. Conference held in Los Alamos, NM 16-20 June 1997. ASP Conference Series. 135. 497–501. Kaye. A. B.. Bagnuolo. W. G.. Hall. D. S.. Henry. G. W. . Bradley . P. A. . Guzik . J. A.. 1998.
- Henry. Gregory W.. Fekel. Francis C.. Six New γ Doradus Stars. Publications of the Astronomical Society of the Pacific. 114. 799. 2002. 988–998. 2002PASP..114..988H. 10.1086/341785.
- Kaye. Anthony B.. Henry. Gregory W.. Fekel. Francis C.. Gray. Richard O.. Rodríguez. Eloy. Martín. Susana. Gies. Douglas R.. Bagnuolo. William G.. Hall. Douglas S.. HD 62454 and HD 68192: Two New γ Doradus Variables. The Astronomical Journal. 118. 6. 1999. 2997–3005. 1999AJ....118.2997K. 10.1086/301136. free.
- Dolez. N.. Vauclair. S.. Michel. E.. Hui-Bon-Hoa. A.. Vauclair. G.. Le Contel. D.. Mathias. P.. Poretti. E.. Amado. P. J.. Rainer. M.. Samadi. R.. Baglin. A.. Catala. C.. Auvergne. M.. Uytterhoeven. K.. Valtier. J.-C.. HD 51106 and HD 50747: an ellipsoidal binary and a triple system observed with CoRoT. Astronomy and Astrophysics. 506. 1. 2009. 159–165. 2009A&A...506..159D. 10.1051/0004-6361/200911903. 0909.5135 .
- Bruntt. H.. Catala. C.. Garrido. R.. Rodríguez. E.. Stütz. C.. Knoglinger. P.. Mittermayer. P.. Bouret. J. C.. Hua. T.. Lignières. F.. Charpinet. S.. Van't Veer-Menneret. C.. Ballereau. D.. Abundance analysis of targets for the COROT/MONS asteroseismology missions. Astronomy and Astrophysics. 389. 1. 2002. 345–354. 2002A&A...389..345B. 10.1051/0004-6361:20020549. astro-ph/0203305 .
- Uytterhoeven. K.. Mathias. P.. Poretti. E.. Rainer. M.. Martín-Ruiz. S.. Rodríguez. E.. Amado. P. J.. Le Contel. D.. Jankov. S.. Niemczura. E.. Pollard. K. R.. Brunsden. E.. Paparó. M.. Costa. V.. Valtier. J.-C.. Garrido. R.. Suárez. J. C.. Kilmartin. P. M.. Chapellier. E.. Rodríguez-López. C.. Marin. A. J.. Aceituno. F. J.. Casanova. V.. Rolland. A.. Olivares. I.. The γ Doradus CoRoT target HD 49434. Astronomy and Astrophysics. 489. 3. 2008. 1213–1224. 2008A&A...489.1213U. 10.1051/0004-6361:200809992. 0807.0904 .
- Henry. Gregory W.. Fekel. Francis C.. Henry. Stephen M.. Photometry and Spectroscopy of 11 γ Doradus Stars. The Astronomical Journal. 133. 4. 2007. 1421–1440. 2007AJ....133.1421H. 10.1086/511820. free. 10.1.1.145.6144.
- Monnier. J. D.. Townsend. R. H. D.. Che. X.. Zhao. M.. Kallinger. T.. Matthews. J.. Moffat. A. F. J.. ROTATIONALLY MODULATEDg-MODES IN THE RAPIDLY ROTATING δ SCUTI STAR RASALHAGUE (α OPHIUCHI). The Astrophysical Journal. 725. 1. 1192. 2010. 2010ApJ...725.1192M. 0004-637X. 10.1088/0004-637X/725/1/1192. 1012.0787 .
- Fekel. Francis C.. Henry. Gregory W.. The Orbit and Pulsation Periods of the γ Doradus Variable HR 6844 (V2502 Ophiuchi). The Astronomical Journal. 125. 4. 2003. 2156–2162. 2003AJ....125.2156F. 10.1086/368121. 10.1.1.8.4250.
- Henry. Gregory W.. Fekel. Francis C.. Kaye. Anthony B.. Kaul. Ann. 10 New γ Doradus and δ Scuti Stars. The Astronomical Journal. 122. 6. 2001. 3383–3395. 2001AJ....122.3383H. 10.1086/324228. free.
- 1995IBVS.4170....1R. A long period early F-type variable: HR8799. Information Bulletin on Variable Stars. 4170. 1. Rodriguez. E.. Zerbi. F. M.. 1995.
- Gray. Richard O.. Kaye. Anthony B.. HR 8799: A Link between γ Doradus Variables and λ Bootis Stars. The Astronomical Journal. 118. 6. 1999. 2993–2996. 1999AJ....118.2993G. 10.1086/301134. free.
- 1997MNRAS.292..621P. Discovery and analysis of Gamma Doradus type pulsations in the F0 IV star HR 2740=QW PUP. Monthly Notices of the Royal Astronomical Society. 292. 3. 621. Poretti. E.. Koen. C.. Martinez. P.. Breuer. F.. Haupt. H.. De Alwis. D.. 1997. 10.1093/mnras/292.3.621. free.
- Peretto I., Lora S., Peretto G., Furlato G., Barbieri M. - MarSEC (2022) - https://www.aavso.org/vsx/index.php?view=detail.top&oid=2227434
