J/AJ/139/2639 DY Peg times of light maximum (Li+, 2010)
A period investigation of the SX Phoenicis star DY Pegasi.
Li L.-J., Qian S.-B.
<Astron. J., 139, 2639-2642 (2010)>
=2010AJ....139.2639L 2010AJ....139.2639L
ADC_Keywords: Stars, variable
Keywords: stars: individual (DY Pegasi) - stars: variables: delta Scuti -
techniques: photometric
Abstract:
We measure two new times of light maximum of the SX Phoenicis star
DY Pegasi in 2008 December and collect 410 pe/CCD times of light
maximum that had been published. These data could be modeled with a
nonlinear fit including a continuously decreasing period change
(dP/dt=-9.04x10-12days/day) and a periodic change with a period of
42.2 yr. If this periodic change is caused by the light traveling time
effect of an orbital motion of DY Pegasi in a binary system, the
deduced mass of the companion could be 0.028M☉ and it is
probably a brown dwarf.
Description:
Observations of DY Pegasi were carried out on 2008 December 12 and 17,
using the 80cm telescope and 50cm telescope at Xinglong observation
station of the National Astronomical Observatories of the Chinese
Academy of Sciences (NAOC).
Objects:
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RA (2000) DE Designation(s)
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23 08 51.19 +17 12 56.0 DY Peg = HD 218549
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 36 412 The 412 available pe/CCD times of light maximum
of DY Pegasi
refs.dat 75 39 References
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
14 A1 --- f_HJD [*] not used in the analysis
16- 18 A3 --- Det Detector (CCD or pe=photoelectric)
20- 25 I6 --- Ep Epoch (cycle) number (2)
27- 33 F7.4 --- (O-C) Residual
35- 36 I2 --- Ref Reference, in refs.dat file
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Note (1): * = not used in the analysis because of large error.
Note (2): cycle from T0=2438276.8643 and P0=0.07292633d
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 44 A21 --- Aut Author's name
46- 75 A30 --- Com Comments
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 03-Jun-2012