J/AJ/153/137 New NSVS 14256825 eclipse times (Nasiroglu+, 2017)
Is there a circumbinary planet around NSVS 14256825?
Nasiroglu I., Gozdziewski K., Slowikowska A., Krzeszowski K., Zejmo M.,
Zola S., Er H., Ogloza W., Drozdz M., Koziel-Wierzbowska D., Debski B.,
Karaman N.
<Astron. J., 153, 137 (2017)>
=2017AJ....153..137N 2017AJ....153..137N (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Stars, subdwarf ; Exoplanets
Keywords: binaries: close - binaries: eclipsing -
planets and satellites: detection -
stars: individual (NSVS 14256825) - subdwarfs
Abstract:
The cyclic behavior of (O-C) residuals of eclipse timings in the sdB+M
eclipsing binary NSVS 14256825 was previously attributed to one or two
Jovian-type circumbinary planets. We report 83 new eclipse timings
that not only fill in the gaps in those already published but also
extend the time span of the (O-C) diagram by three years. Based on the
archival and our new data spanning over more than 17 years, we
re-examined the up-to-date system (O-C). The data revealed a
systematic, quasi-sinusoidal variation deviating from an older linear
ephemeris by about 100 s. It also exhibits a maximum in the (O-C) near
JD 2456400 that was previously unknown. We consider two most credible
explanations of the (O-C) variability: the light propagation time due
to the presence of an invisible companion in a distant circumbinary
orbit, and magnetic cycles reshaping one of the binary components,
known as the Applegate or Lanza-Rodono effect. We found that the
latter mechanism is unlikely due to the insufficient energy budget of
the M-dwarf secondary. In the framework of the third-body hypothesis,
we obtained meaningful constraints on the Keplerian parameters of a
putative companion and its mass. Our best-fitting model indicates that
the observed quasi-periodic (O-C) variability can be explained by the
presence of a brown dwarf with the minimal mass of 15 Jupiter masses
rather than a planet, orbiting the binary in a moderately elliptical
orbit (e∼0.175) with a period of ∼10 years. Our analysis rules
out the two-planet model proposed earlier.
Description:
In this study, we present 83 new mid-eclipse times of NSVS 14256825
obtained between 2009 August 21 and 2016 November 03 that together with
the literature data give 153 eclipses over the time span of 17 years.
We combined our new data with the previously published measurements to
analyze the orbital period variations of this system.
We performed photometric observations of NSVS 14256825 with five
different telescopes: the 1.3 m telescope at the Skinakas Observatory
(SKO, Creete, Greece), the 0.5 m telescope at the Astronomical Observatory
of the Jagiellonian University (KRK, Krakow, Poland), the 0.6 m telescope
at the Mt. Suhora Observatory (SUH, Koninki, Poland), the 0.6 m telescope
at the Adiyaman University Observatory (ADYU60, Adiyaman, Turkey), and
the 1 m telescope at the TUBITAK National Observatory (TUG, Antalya,
Turkey).
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
20 20 00.46 +04 37 56.5 NSVS 14256825 = V* V1828 Aql
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 43 83 List of new NSVS 14256825 eclipse times
table3.dat 43 83 NSVS 14256825 observations log
table4.dat 43 153 List of the NSVS 14256825 eclipse times from
the literature and new measurements
--------------------------------------------------------------------------------
See also:
J/A+A/566/A128 : Period variations in SuperWASP PCEB (Lohr+, 2014)
J/AJ/147/45 : Kepler mission. IV. Eclipse times for close binaries
(Conroy+, 2014)
J/MNRAS/453/3474 : ASAS, NSVS, and LINEAR detached eclipsing binaries
(Lee, 2015)
Byte-by-byte Description of file: table1.dat table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/153]? Data point number (not in table 1)
5- 12 F8.1 --- Cycle [-26586/31004] Cycle number (G1)
14- 27 F14.6 d BJD Barycentric Julian Date of minimum
29- 36 F8.6 d e_BJD Uncertainty in BJD
38- 39 I2 s e_BJDs [0/86]? Uncertainty in BJD, in seconds
(not in table 1)
41 I1 --- Type [1/2] Eclipse type (1=Primary, 2=Secondary)
43 I1 --- Ref [1/9] Reference (1)
--------------------------------------------------------------------------------
Note (1): Note that data from Lohr et al. (2014, J/A+A/566/A128) (see the
Astro-ph version, 1405.6001) are not included in this table.
References correspond to the following papers:
1 = Wils et al. (2007IBVS.5800....1W 2007IBVS.5800....1W);
2 = Beuermann et al. (2012A&A...540A...8B 2012A&A...540A...8B);
3 = Kilkenny & Koen (2012MNRAS.421.3238K 2012MNRAS.421.3238K);
4 = Almeida et al. (2013ApJ...766...11A 2013ApJ...766...11A);
5 = Astronomical Observatory of the Jagiellonian University (this work);
6 = Mt. Suhora Observatory (this work);
7 = Skinakas Observatory (this work);
8 = TUBITAK National Observatory (this work);
9 = Adiyaman University Observatory (this work).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Date Starting date of observation
12- 18 F7.1 --- Cycle [7167.5/31004] Cycle number (G1)
20 I1 --- Type [1/2] Eclipse type (1=Primary, 2=Secondary)
22- 28 A7 --- Filter Filter (W-light, R or BG40)
30- 31 I2 s Exp [3/20] Exposure time
33- 36 F4.1 s Read [1/20] Readout time
38- 43 A6 --- Obs Observatory code (1)
--------------------------------------------------------------------------------
Note (1): Observatory code as follows:
KRK = the Astronomical Observatory of the Jagiellonian University;
SUH = the Mt. Suhora Observatory;
SKO = the Skinakas Observatory;
TUG = the TUBITAK National Observatory;
ADYU60 = the Adiyaman University Observatory.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Cycle numbers according to the ephemeris from Beuermann et al.
(2012A&A...540A...8B 2012A&A...540A...8B).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 04-May-2018