J/ApJ/907/70 Spectroscopic observation of Nova Cas 2020 with FKO (Fujii+, 2021)
Transient Formation of C2 and CN in the Near-maximum Phase of
Nova Cas 2020(=V1391 Cas)
Fujii M., Arai A., Kawakita H.
<Astrophys. J., 907, 70 (2021)>
=2021ApJ...907...70F 2021ApJ...907...70F
ADC_Keywords: Novae; Spectra, optical; Spectra, infrared
Keywords: Classical novae ; Slow novae ; DQ Herculis stars
Abstract:
Nova Cas 2020 was a second example of a classical nova forming both
C2 and CN molecules during its near-maximum phase. The formation
C2 and CN is indicative of the carbon-rich (C/O>1) gas envelope of
the nova. Our low-resolution spectroscopic observations in the optical
from UT 2020 July 31 to August 19 revealed the appearance and the
disappearance of the molecular absorption bands of C2 and CN in Nova
Cas 2020. These molecules were present during ∼3days only. Based on
analysis of the C2 Swan band profiles, C2 (and probably CN also)
formed at ∼5000K in the nova envelope (see ∼8000K for typical novae at
their visual brightness maxima). Spectral evolution and the formation
conditions of the molecules are similar to those of V2676 Oph, which
is the first example of a C2/CN-forming nova. We predict that a
late-phase grain formation episode similar to that seen in V2676 Oph
will occur in Nova Cas 2020.
Description:
We conducted the low-resolution spectroscopic observations using the
0.4m telescope (f/10) with a low-resolution spectrograph FBSPEC-III
(R=640 at a wavelength of Hα, corresponding to a slit width of
5") at Fujii-Kurosaki Observatory (FKO).
Objects:
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RA (2000) DE Designation(s)
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00 11 42.97 +66 11 19.0 Nova Cas 2020 = V* V1391 Cas
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
20200731.dat 16 1620 Data observed on 2020 Jul 31
20200810.dat 16 1619 Data observed on 2020 Aug 10
20200812.dat 16 1619 Data observed on 2020 Aug 12
20200813.dat 16 1619 Data observed on 2020 Aug 13
20200814.dat 16 1619 Data observed on 2020 Aug 14
20200815.dat 16 1619 Data observed on 2020 Aug 15
20200816.dat 16 1619 Data observed on 2020 Aug 16
20200817.dat 16 1619 Data observed on 2020 Aug 17
20200818.dat 16 1619 Data observed on 2020 Aug 18
20200819.dat 16 1619 Data observed on 2020 Aug 19
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See also:
J/ApJS/214/26 : Line lists for CN isotopes transitions (Sneden+, 2014)
Byte-by-byte Description of file: 20200[78][13][0123456789].dat
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Bytes Format Units Label Explanations
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1- 4 I4 0.1nm Wave [4500/9000] Wavelength (Angstrom)
6- 16 E11.6 --- Flux [1e-15/1e-11] Normalized flux
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History:
From electronic version of the journal
(End) Prepared by Coralie Fix [CDS], 14-Jun-2022