V603 Aquilae (or Nova Aquilae 1918) was a bright nova first observed (from Earth) in the constellation Aquila in 1918. It was the brightest "new star" to appear in the sky since Kepler's Supernova in 1604. Like all novae, it is a binary system, comprising a white dwarf and donor low-mass star in close orbit to the point of being only semidetached. The white dwarf sucks matter off its companion, which has filled its Roche lobe,[3] onto its accretion disk and surface until the excess material is blown off in a thermonuclear event.[4] This material then forms an expanding shell, which eventually thins out and disappears.[3]

V603 Aquilae or Nova Aquilae 1918
Location of V603 Aquilae (circled in red)
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 18h 48m 54.637s[1]
Declination 00° 35′ 02.86″[1]
Apparent magnitude (V) 11.64
Characteristics
Spectral type sd:Be+
B−V color index -0.2 ± 0.5
Variable type Nova
Astrometry
Radial velocity (Rv)−23 km/s
Proper motion (μ) RA: 10.81 mas/yr
Dec.: −8.86 mas/yr
Distance1,020+23
−23
 ly
(314+7
−7
[2] pc)
Absolute magnitude (MV)11.65
Other designations
Nova Aql 1918, Nova Aquilae 1918, EM* CDS 1028, HD 174107, 1RXS J184854.7+003501, ALS 9992, 1ES 1846+00.5, SBC7 706, AN 7.1918, FASTT 1189, HIP 92316, UBV M 51004, CSI+00-18463, GCRV 68659, KPD 1846+0031, 2E 1846.3+0031, LS IV +00 3, 2E 4138, GSC 00448-00423, 2MASS J18485464+0035030, EM* RJHA 116, HBHA 202-05, PLX 4341, AAVSO 1843+00.
Database references
SIMBADdata
The light curve of V603 Aquilae, from AAVSO visual band data

First seen by Zygmunt Laskowski, a medical professor and amateur astronomer,[5] and then confirmed on the night of 8 June 1918 by the UK amateur astronomer Grace Cook,[6] Nova Aquilae reached a peak magnitude of −0.5; it was the brightest nova recorded in the era of the telescope.[4] It was brighter than all stars but Sirius and Canopus.[7] Tycho's and Kepler's supernovae were brighter, but both occurred before the invention of the telescope.[8] Originally a star system with a magnitude of 11.43, it took twelve days to fade three magnitudes and then 18.6 years to fade to quiescence.[4] In 1964 Robert P. Kraft ascertained that it was a binary system, recently[when?] determined to be true for several other novae at the time.[9]

The star system has settled to an average apparent magnitude of 11.4 since the 1940s, fading by around 1/100 of a magnitude per decade. The nova's parallax, 3.191±0.069 milliarcseconds, was measured by the Gaia spacecraft which implies a distance of 1020±23 light years.[2] Spectroscopic analysis conducted by Arenas and colleagues indicated the system consisted of a white dwarf of about 1.2 times as massive as the sun, with an accretion disk, and a companion star with about 20% of the Sun's mass.[10] This second star is most likely a red dwarf.[3] The two stars orbit each other approximately every 3 hours 20 minutes.[10]

In 1983 VLA observations detected radio emission from this nova at 5 GHz.[11] The upgraded JVLA detected 8.9 GHz emission in 2013,[12] and MeerKAT detected 1.3 GHz emission in 2019.[13] The radio emission is consistent with gyrosynchrotron, cyclotron maser and optically thick synchrotron emission.[13]

References edit

  1. ^ a b "V603 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 4 December 2020.
  2. ^ a b Schaefer, Bradley E. (December 2018). "The distances to Novae as seen by Gaia". Monthly Notices of the Royal Astronomical Society. 481 (3): 3033–3051. arXiv:1809.00180. Bibcode:2018MNRAS.481.3033S. doi:10.1093/mnras/sty2388.
  3. ^ a b c Selvelli, P. L.; Cassatella, A. (1981). "Nova AQL 1918: A Nude Old Nova". Effects of Mass Loss on Stellar Evolution. Astrophysics and Space Science Library. Vol. 89. pp. 515–522. Bibcode:1981ASSL...89..515S. doi:10.1007/978-94-009-8500-1_74. ISBN 978-94-009-8502-5. S2CID 222335225.
  4. ^ a b c Johnson, Christopher B.; Schaefer, Bradley E.; Kroll, Peter; Henden, Arne A. (2013). "Nova Aquilae 1918 (V603 Aql) Faded by 0.44 mag/century from 1938-2013". The Astrophysical Journal. 780 (2): L25. arXiv:1310.6802. Bibcode:2014ApJ...780L..25J. doi:10.1088/2041-8205/780/2/L25. S2CID 118403602.
  5. ^ The Contribution of Amateurs to Astronomy, Proceedings of Colloquium 98 of the International Astronomical Union, June 20–24, 1987, page 41
  6. ^ Mobberley, Martin (2009). Cataclysmic Cosmic Events and How to Observe Them. Springer. p. 46. ISBN 978-0-387-79946-9.
  7. ^ Moore, Patrick (2006). The Amateur Astronomer. Springer. p. 145. ISBN 978-1-84628-286-7.
  8. ^ Drechsel, H.; Holm, A.; Krautter, J. & Rahe, J. (1981). "Phase-dependent optical and ultraviolet observations of the old nova V603 Aquilae (1918)". Astronomy & Astrophysics. 99 (1): 166–72. Bibcode:1981A&A....99..166D.
  9. ^ Kraft, Robert P. (1964). "Binary stars among cataclysmic variables. III. Ten old novae". Astrophysical Journal. 139: 457–75. Bibcode:1964ApJ...139..457K. doi:10.1086/147776.
  10. ^ a b Arenas, J.; Catalán, M. S.; Augusteijn, T.; Retter, A. (2000). "A spectroscopic study of V603 Aquilae: stellar parameters and continuum-line variations". Monthly Notices of the Royal Astronomical Society. 311 (1): 135–48. Bibcode:2000MNRAS.311..135A. doi:10.1046/j.1365-8711.2000.03061.x.
  11. ^ Fuerst, E.; Benz, A.; Hirth, W.; Kiplinger, A.; Geffert, M. (January 1986). "Radio emission of cataclysmic variable stars". Astronomy and Astrophysics. 154: 377–378. Bibcode:1986A&A...154..377F. Retrieved 4 December 2020.
  12. ^ Barrett, Paul E.; Dieck, Christopher; Beasley, Anthony J.; Singh, Kulinder P.; Mason, Paul A. (November 2017). "A Jansky VLA Survey of Magnetic Cataclysmic Variable Stars. I. The Data". The Astronomical Journal. 154 (6): 252. arXiv:1702.07631. Bibcode:2017AJ....154..252B. doi:10.3847/1538-3881/aa93ff. S2CID 119055826.
  13. ^ a b Hewitt, D.M.; Pretorius, M.L.; Woudt, P.A.; Tremou, E.; Miller-Jones, J.C.A; Knigge, C.; CastroSegura, N.; Williams, D.R.A.; Fender, R.P.; Armstrong, R.; Groot, P.; Heywood, I.; Horesh, A.; vanderHorst, A.J.; Koerding, E.; McBride, V.A.; Mooley, K.P.; Rowlinson, A.; Stappers, B.; Wijers, R.A.M.J. (22 June 2020). "A MeerKAT survey of nearby nova-like cataclysmic variables". Monthly Notices of the Royal Astronomical Society. 496 (3): 2542–2557. arXiv:2006.07918. doi:10.1093/mnras/staa1747.

External links edit