J/MNRAS/447/1661 Optical photometry of nova V5588 Sgr (Munari+, 2015)
The hybrid, coronal lines nova V5588 Sgr (2011 N.2) and its six repeating
secondary maxima.
Munari U., Henden A., Banerjee D.P.K., Ashok N.M., Righetti G.L.,
Dallaporta S., Cetrulo G.
<Mon. Not. R. Astron. Soc., 447, 1661-1672 (2015)>
=2015MNRAS.447.1661M 2015MNRAS.447.1661M (SIMBAD/NED BibCode)
ADC_Keywords: Novae ; Photometry, UBVRI
Keywords: novae, cataclysmic variables
Abstract:
The outburst of Nova Sgr 2011 N.2 (=V5588 Sgr) was followed with optical
and near-IR photometric and spectroscopic observations for 3.5 yr,
beginning shortly before the maximum. V5588 Sgr is located close to
Galactic Centre, suffering from E(B-V)=1.56(±0.1) extinction. The
primary maximum was reached at V=12.37 on UT 2011 April 2.5(±0.2),
and the underlying smooth decline was moderately fast with tV2=38
and tV3=77 d. On top of an otherwise normal decline, six self-similar,
fast evolving and bright secondary maxima (SdM) appeared in succession.
Only very few other novae have presented so clear SdM. Both the primary
maximum and all SdM occurred at later times with increasing wavelengths,
by amounts in agreement with expectations from fireball expansions.
The radiative energy released during SdM declined following an exponential
pattern, while the breadth of individual SdM and the time interval between
them widened. Emission lines remained sharp (FWHM∼1000 km/s) throughout
the whole nova evolution, with the exception of a broad pedestal with
a trapezoidal shape (Δvel=3600 km/s at the top and 4500 km/s at
the bottom) which was only seen during the advanced decline from SdM maxima
and was absent in between SdM. V5588 Sgr at maximum light displayed a
typical FeII-class spectrum which did not evolve into a nebular stage.
About 10 d into the decline from primary maximum, a typical high-ionization
He/N-class spectrum appeared and remained visible simultaneously with
the FeII-class spectrum, qualifying V5588 Sgr as a rare hybrid nova. While
the FeII-class spectrum faded into oblivion, the He/N-class spectrum
developed strong [FeX] coronal lines.
Description:
BVRCIC optical photometry was obtained with (a) ANS Collaboration
telescopes N. 30, 37, 100 and 157, and (b) AAVSO.net telescopes K35 and
T61. The same local photometric sequence, spanning a wide colour range
and carefully calibrated against Landolt (2009, J/AJ/137/4186) equatorial
standards, was used at all telescopes and observing epochs, ensuing a high
consistency among different data sets. The operation of ANS Collaboration
telescopes is described in detail by Munari et al. (2012BaltA..21...13M 2012BaltA..21...13M )
and Munari & Moretti (2012BaltA..21...22M 2012BaltA..21...22M ). They are all located in Italy.
Both AAVSO.net telescopes K35 and T61 are robotically operated from AAVSO
Headquarters in Cambridge (MA, USA). K35 (located in Weed NM, USA) was used
during the initial monitoring of the nova up to the end of June 2011, when
the arrival of the monsoon season prevented further observations, which
briefly resumed in October 2011 before the solar conjunction.
Objects:
---------------------------------------------------------
RA (ICRS) DE Designation(s)
---------------------------------------------------------
18 10 21.35 -23 05 30.6 V5588 Sgr = NOVA Sgr 2011 b
---------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 103 179 BVRCIC photometry of V5588 Sgr
--------------------------------------------------------------------------------
See also:
B/vsx : AAVSO International Variable Star Index VSX
(Watson+, 2006-2014)
J/AJ/137/4186 : UBVRI standards around celestial equator (Landolt, 2009)
J/AJ/140/34 : Classification of nova light curves (Strope+, 2010)
J/A+A/554/A123 : Near-IR catalog of novae in VVV survey area (Saito+, 2013)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.3 d HJD Heliocentric Julian Date
13- 15 A3 --- Tel Telescope identifier
17- 22 F6.3 mag Vmag [11.304/17.667] V band magnitude
24- 28 F5.3 mag e_Vmag [0.002/0.118] Uncertainty in Vmag
30- 34 F5.3 mag B-V [1.114/2.03]? B-V colour index
36- 40 F5.3 mag e_B-V [0.003/0.261]? Uncertainty in B-V
42- 46 F5.3 mag V-Rc [1.389/3.697]? V-Rc colour index
48- 52 F5.3 mag e_V-Rc [0.001/0.121]? Uncertainty in V-Rc
54- 58 F5.3 mag V-Ic [1.841/3.115]? V-Ic colour index
60- 64 F5.3 mag e_V-Ic [0.004/0.125]? Uncertainty in V-Ic
66- 71 F6.3 mag Bmag [13.194/17.624]? B band magnitude
73- 77 F5.3 mag e_Bmag [0.005/0.109]? Uncertainty in Bmag
79- 84 F6.3 mag Rcmag [9.917/13.856]? Rc band magnitude
86- 90 F5.3 mag e_Rcmag [0.002/0.018]? Uncertainty in Rcmag
92- 97 F6.3 mag Icmag [9.08/13.952]? Ic band magnitude
99-103 F5.3 mag e_Icmag [0.002/0.025]? Uncertainty in Icmag
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 25-Oct-2019