J/other/NewA/15.108 UBVRIHα of η Car in 2009 (Fernandez-Lajus+ 2010)
The η Carinae optical 2009.0 event, a new "eclipse-like" phenomenon.
Fernandez-Lajus E., Farina C., Calderon J.P., Salerno N., Torres A.F.,
Schwartz M.A., von Essen C., Giudici F., Bareilles F.A.
<New Astron., 15, 108-112 (2010)>
=2010NewA...15..108F 2010NewA...15..108F
ADC_Keywords: Stars, variable ; Photometry, CCD ; Photometry, UBVRI ;
Photometry, H-alpha
Keywords: stars: individual (eta Carinae) - stars: variables: general -
stars: binaries: close - techniques: photometric
Abstract:
The periodic events occurring in η Carinae have been widely
monitored during the last three 5.5-year cycles. The last one recently
occurred in January 2009 and more exhaustive observations have been
made at different wavelength ranges. If these events are produced when
the binary components approach periastron, the timing and sampling of
the photometric features can provide more information about the
geometry and physics of the system.
Thus, we continued with our ground-based optical photometric campaign
started in 2003 to record the behaviour of the 2009.0 event in detail.
This time the observation program included a new telescope to obtain
information from other photometric bands. The daily monitoring
consists of the acquisition of CCD images through standard UBVRI
filters and a narrow Hα passband. The subsequent differential
photometry includes the central region of the object and the whole
Homunculus nebula. The results of our relative UBVRIHα
photometry, performed from November 2008 up to the end of March 2009,
are presented in this work, which comprises the totality of the event.
The initial rising branch, the maximum, the dip to the minimum and the
recovering rising phase strongly resemble a kind of eclipse. All these
features happened on time - according to that predicted - although
there are some photometric differences in comparison with the previous
event. We made a new determination of 2022.8 days for the period value
using the present and previous "eclipse-like" event data. These
results strongly support the binarity hypothesis for η Car. In
this paper, the complete dataset with the photometry of the 2009.0
event is provided to make it readily available for further analysis.
Objects:
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RA (2000) DE Designation(s)
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10 45 03.6 -59 41 04 eta Car = V* eta Car
10 45 06.8 -59 41 57 CPD-59 2627 = Cl* Trumpler 16 MJ 488
10 45 08.3 -59 40 50 CPD-59 2628 = V* V573 Car
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 70 1300 UBVRIHα light curves of η Car
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See also:
J/A+A/304/415 : uvby-Hbeta photometry of Eta Car 1992-94 (van Genderen+, 1995)
J/A+A/343/847 : Geneva Photometry of Eta Car (van Genderen+ 1999)
J/A+A/419/215 : Emission lines of eta Car (Hartman+, 2004)
J/A+A/493/1093 : BVRI light curves of eta Car (Fernandez-Lajus+, 2009)
J/AJ/129/2018 : RXTE scaled fluxes of eta Car (Corcoran+, 2005)
J/ApJS/71/983 : UV spectrum of eta Car (Viotti+ 1989)
J/ApJS/157/138 : UV spectrum of eta Car (Nielsen+, 2005)
J/ApJS/163/173 : UV spectrum of eta Car in 2003.5 (Gull+, 2006)
J/ApJS/168/289 : NUV spectrum of eta Car in 2003.5 (Nielsen+, 2007)
J/A+A/493/1093 : BVRI light curves of eta Car (Fernandez-Lajus+, 2009)
J/ApJS/181/473 : Eta Carinae: visible and near-IR analysis (Nielsen+, 2009)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d JD Julian date
14- 15 A2 --- Band [UBVRI Ha] Photometric band
17- 22 F6.3 mag Dmag η Car mean differential magnitude
24- 28 F5.3 mag e_Dmag η Car rms error of the mean magnitude
30- 34 F5.3 mag DmagT1 ?=- CPD-59 2627 (Test1) mean differential
magnitude
36- 40 F5.3 mag e_DmagT1 ?=- CPD-59 2627 rms error of the mean magnitude
42- 46 F5.3 mag DmagT2 ?=- CPD-59 2628 (Test2) mean differential
magnitude
48- 52 F5.3 mag e_DmagT2 ?=- CPD-59 2628 rms error of the mean magnitude
54- 56 F3.1 arcsec FWHM Full width half maximum of HDE303308
58- 59 I2 --- Nimages Number of images considered for the mean values
61- 70 A10 --- Tel/Obs Telescope and Observatory Ids (1)
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Note (1): Telescopes and Observatories as follows:
HSH/CASLEO = HSH telescope at CASLEO observatory
VSN/OALP = VSN telescope at OALP observatory
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Acknowledgements:
Eduardo Fernandez-Lajus, eflajus(at)fcaglp.unlp.edu.ar
(End) E. Fernandez-Lajus [Univ. Nac. La Plata, Arg.], Vannier [CDS] 14-Jul-2009