V606 Aquilae

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Double star
V606 Aquilae
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Eagle
Right ascension 19 h 20 m 24.29 s
declination -00 ° 08 ′ 7.8 ″
Apparent brightness 20.4 mag
Typing
B − V color index 0.41 
U − B color index −0.28 
Spectral class Q
Variable star type N / A 
Astrometry
Physical Properties
Other names
and catalog entries
Henry Draper Catalog HD 181419 [1]
Other names NOVA Aql 1899, IC 4850, AAVSO 1915-00, AN 11.1900, BD-00 3708, HV 130,

V606 Aquilae was a barely observed nova discovered by Williamina Fleming as a seventh magnitude objecton a photographic plate on April 18, 1899, as reported by Edward Charles Pickering in 1900.

The brightness of the nova on this plate was later determined more precisely by Henrietta Swan Leavitt to be 6.75 m . There is an observation gap of about 200 days before discovery. It is therefore possible that the actual maximum was missed. The reference catalog and an atlas of the galactic novas by Hilmar W. Duerbeck estimate the maximum brightness to be 5.5 m .

The observed drop in the light curve covers approx. 160 days and suggests classification as type "P". In 1991 Ringwald et al. obtained a spectroscopy of the suspected after-effects of the nova, but found an object with a spectrum from G7 to K4 and V = 16.3 m .

The southwest component of an unresolved visual binary system , marked as a possible postnova in the Catalog and Atlas of Cataclysmic Variables , showed a promising spectrum. The subsequent spectroscopy of the object with V = 20.4 m confirmed the nova. The spectrum showed comparatively strong Balmer emission lines , although not as strong as in EL Aquilae . However, the high excitation lines are considerably weaker and He II λ5412 emission lines were not detected. It found that most of the P-Class members appeared to be recurrent or magnetic novae.

Even if the actually observed maximum brightness is used to calculate the outbreak amplitude, the result of ∆m = 13.6 m appears much too large for a recurring nova (Pagnotta & Schaefer 2014). On the other hand, the spectroscopic properties do not show any particularly strong evidence for a magnetic cause.

Apparently, V606 Aquilae is an unusual member of the P-class. The spectrum shows a slight increase in the blue continuum and the two-color diagram (English color-color diagram) shows that the field is only moderately affected by the interstellar extinction .

After a downgrade with a value of E (B - V) = 0.35 (03) m , it became clear that the continuum was distorted by a series of large "humps". After examining the three individual spectra, it came to the conclusion that this uneven course of the curve is not a real measurement result , but is due to interference signals. However, these bumps made large parts of the continuum unusable for analysis. A number of smaller areas of the continuum between the blue emission lines and some regions around 6,000 Å were therefore selected to determine a negative exponent of α = 2.02 (02).

After examining the Hα line profile of the individual spectra, it turned out that the deviations were not as noticeable as in EL Aquilae , and the Doppler shift of the entire profile is not as large as assumed. Nevertheless, the shape of the line profile is characteristic of cataclysmic variables and the width of the emission lines is essentially identical to the Nova EL Aquilae of 1927. It is therefore assumed that V606 Aquilae is also likely to be seen under a moderately high orbital inclination , making it one potential object for follow-up observation.

Individual evidence

  1. ↑ a b c HD 181419. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on March 29, 2019 .
  2. ↑ a b c V0606 Aql. In: VSX. AAVSO , accessed March 28, 2019 .
  3. ↑ a b c d e C. Tappert, D. Barria, I. Fuentes Morales, N. Vogt, A. Ederoclite, L. Schmidtobreick, August 1, 2016: Life after eruption - VI. Recovery of the old novae EL Aql, V606 Aql, V908 Oph, V1149 Sgr, V1583 Sgr and V3964 Sgr In: Cornell University Solar and Stellar Astrophysics (astro-ph.SR), doi: 10.1093 / mnras / stw1748 .
  4. ↑ 1777 variables in the Magellanic Clouds. In: Annals of Harvard College Observatory, vol. 60, pp.87-108.3, Leavitt, HS 1908, accessed April 1, 2019 .
  5. ↑ Duerbeck, Hilmar W.:A reference catalog and atlas of galactic novae In: Space Science Reviews (ISSN 0038-6308), vol. 45, no. 1-2, 1987, p. 1-212, doi: 10.1007 / BF00187826 .
  6. ↑ Strope, Richard J .; Schaefer, Bradley E .; Henden, Arne A.:Catalog of 93 Nova Light Curves: Classification and Properties In: The Astronomical Journal, Volume 140, Issue 1, pp. 34-62 (2010), doi: 10.1088 / 0004-6256 / 140/1/34 .
  7. ↑ Michael J. Gariety and FA Ringwald: A critical analysis of three near-infrared photometric methods of estimating distances to cataclysmic variables In: New Astronomy, Solar and Stellar Astrophysics (astro-ph.SR), doi: 10.1016 / j.newast. 2011.07.010 .
  8. ↑ Pagnotta, Ashley; Schaefer, Bradley E.: Identifying and Quantifying Recurrent Novae Masquerading as Classical Novae In: The Astrophysical Journal, Volume 788, Issue 2, article id. 164, 25 pp. (2014), doi: 10.1088 / 0004-637X / 788/2/164 .