V603 Aquilae

V603 Aquilae (or Nova Aquilae 1918) was a bright nova first observed (from Earth) in the constellation Aquila in 1918. 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,[2] onto its accretion disk and surface until the excess material is blown off in a thermonuclear event.[3] This material then forms an expanding shell, which eventually thins out and disappears.[2]

V603 Aquilae or Nova Aquilae 1918
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 18h 48m 54.6366s
Declination +00° 35′ 02.863″
Apparent magnitude (V) 11.64
Spectral type sd:Be+
B−V color index -0.2 ± 0.5
Variable type Variable star
Radial velocity (Rv)−23 km/s
Proper motion (μ) RA: 10.81 mas/yr
Dec.: −8.86 mas/yr
[1] 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

First seen by Zygmunt Laskowski, a medical professor and amateur astronomer,[4] and then confirmed on the night of 8 June 1918 by the UK amateur astronomer Grace Cook,[5] The nova is estimated at between 784 to 839 light years distance from Earth [1]. Nova Aquilae reached a peak magnitude of −0.5; it was the brightest nova recorded in the era of the telescope.[3] It was brighter than all stars but Sirius and Canopus.[6] Tycho's and Kepler's supernovae were brighter, but both occurred before the invention of the telescope.[7] 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.[3] 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.[8]

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. 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.[9] This second star is most likely a red dwarf.[2] The two stars orbit each other approximately every 3 hours 20 minutes.[9]


  1. ^ a b Harrison, Thomas E.; et al. (2013). "Hubble Space Telescope Fine Guidance Sensor Parallaxes for Four Classical Novae". The Astrophysical Journal. 767 (1). 7. arXiv:1302.3245. Bibcode:2013ApJ...767....7H. doi:10.1088/0004-637X/767/1/7. S2CID 118376206.
  2. ^ a b c Selvelli, P. L.; Cassatella, A. (1981). "Nova AQL 1918 - A nude old nova". In: Effects of Mass Loss on Stellar Evolution; Proceedings of the Fifty-ninth Colloquium, Trieste, Italy, September 15–19, 1980. (A82-33926 16-90) Dordrecht, D. Reidel Publishing Co. Astrophysics and Space Science Library. 89: 515–522. Bibcode:1981ASSL...89..515S. doi:10.1007/978-94-009-8500-1_74. ISBN 978-94-009-8502-5.
  3. ^ 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.
  4. ^ The Contribution of Amateurs to Astronomy, Proceedings of Colloquium 98 of the International Astronomical Union, June 20–24, 1987, page 41
  5. ^ Mobberley, Martin (2009). Cataclysmic Cosmic Events and How to Observe Them. Springer. p. 46. ISBN 978-0-387-79946-9.
  6. ^ Moore, Patrick (2006). The Amateur Astronomer. Springer. p. 145. ISBN 978-1-84628-286-7.
  7. ^ 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.
  8. ^ 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.
  9. ^ 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.

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