EL Aquilae
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20.9[3] Min.
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 18h 56m 02.030s[1][a] |
| Declination | −03° 19′ 20.43″[1] |
| Apparent magnitude (V) | 6.4[2] Max. 20.9[3] Min. |
| Characteristics | |
| Variable type | Classical Nova |
| Astrometry | |
| Proper motion (μ) | RA: −2.236[1] mas/yr Dec.: −6.157[1] mas/yr |
| Parallax (π) | 0.1601±0.0779 mas[1] |
| Distance | approx. 20,000 ly (approx. 6,000 pc) |
| Other designations | |
| Nova Aql 1927, AAVSO 1850-03, Gaia DR2 4255780873390406528[4] | |
| Database references | |
| SIMBAD | data |
EL Aquilae, also known as Nova Aquilae 1927 was a nova that appeared in 1927. It was discovered by Max Wolf on photographic plates taken at Heidelberg Observatory on 30 and 31 July 1927 when it had a photographic magnitude of 9. Subsequent searches of plates taken at the Harvard College Observatory showed the nova was fainter than magnitude 11.1 on 8 June 1927 and had flared to magnitude 6.4 on 15 June 1927.[5][7] It declined from peak brightness at an average rate of 0.105 magnitudes per day, making it a fast nova, and ultimately dimmed to about magnitude 21.[2] The 14.5 magnitude change from peak brightness to quiescence was unusually large for a nova.[3]
All novae are binary stars, with a "donor" star orbiting a white dwarf so closely that matter is transferred from the donor to the white dwarf. Pagnotta & Schaefer argued that the donor star for the EL Aquilae system is a red giant, based on its position in an infrared color–color diagram.[8] Tappert et al. suggest that Pagnotta & Schaefer misidentified EL Aquilae, and claim that EL Aquilae is probably an intermediate polar, a nova with a main sequence donor star, based on its eruption amplitude and color.[3]
