J/AJ/152/199 BV(RI)c light curves of FF Vul (Samec+, 2016)
BVRI observations and analyses of the semidetached binary FF Vulpecula.
Samec R.G., Nyaude R., Caton D., Van Hamme W.
<Astron. J., 152, 199-199 (2016)>
=2016AJ....152..199S 2016AJ....152..199S (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI
Keywords: binaries: eclipsing - stars: evolution - stars: individual: FF VUL
Abstract:
High-precision BVRcIc light curves of FF Vul were taken during the
fall of 2015 with the Dark Sky Observatory 0.81m reflector of
Appalachian State University, and the SARA north 0.91m reflector at
KPNO. FF Vul is an eclipsing binary with a period of 0.44 day. A
Wilson-Devinney solution shows that the binary is a near-contact,
semidetached binary, i.e., with a V1010 Oph-type configuration. Five
eclipse timings (three primary and two secondary) were calculated. A
quadratic ephemeris was determined indicating that the period is
decreasing. A near-equatorial hot spot was modeled on the cooler,
secondary star, possibly caused by matter impacting from the primary
component via the inner Lagrangian point. The component temperature
difference is more than 1500K. The solution confirms a total secondary
eclipse of 23 minutes duration. As expected in binaries of this type,
there is a magnetic spot region.
Description:
The present BVRcIc light curves were taken by DC, RS, and RN with
the Dark Sky Observatory 0.81m reflector at Phillips Gap, North
Carolina. These were taken on 2015 September 12, 13, 14 and 15, and
October 15, with a thermoelectrically cooled (-40°C) 2*2K Apogee
Alta camera. Additional observations were obtained remotely with the
SARA north 0.91m reflector at KPNO on 2015 September 20 and October
11, with the ARC 2*2K camera cooled to -110°C.
Individual observations were taken at both sites with standard
Johnson-Cousins filters, and included 444 field images in B, 451 in V,
443 in Rc, and 445 in Ic. The standard error was ∼7mmag in each of
B, V, Rc and Ic. Nightly images were calibrated with 25 bias
frames, five flat frames in each filter, and ten 300s dark frames.
The exposure times were 40-50s in B, 25-30s in V, 15-25s in Rc and
Ic. Our observations are listed in Table1.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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20 23 12.96 +25 42 58.8 V* FF Vul = SV* GR 48 (P=0.444983)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 16 1784 Observations of FF Vul
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/AN/334/860 : Catalogue of eclipsing variables. Version 2 (Avvakumova+, 2013)
J/AJ/136/1067 : New beta Lyrae and Algol candidates in NSVS (Hoffman+, 2008)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Flt [BVRI] Filter (Johnson-Cousins B, V, Rc,
or Ic)
3- 9 F7.4 d HJD [7.5/40.8] Modified Heliocentric Julian Date
(HJD-2457270)
11- 16 F6.3 mag Dmag [-0.22/0.84] The Δ magnitude in Flt (1)
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Note (1): In the sense variable minus the comparison star (UCAC3 232-224876).
The standard error was ∼7mmag in each of B, V, Rc and Ic.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 03-Feb-2017