J/ApJ/820/87 XO-4b 3yr observations with DEMONEX (Villanueva+, 2016)
The DEdicated MONitor of EXotransits (DEMONEX): seven transits of XO-4b.
Villanueva S.JR, Eastman J.D., Gaudi B.S.
<Astrophys. J., 820, 87 (2016)>
=2016ApJ...820...87V 2016ApJ...820...87V (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, SDSS ; Stars, double and multiple ; Planets
Keywords: methods: data analysis; planetary systems; stars: individual: XO-4;
techniques: photometric; techniques: radial velocities
Abstract:
The DEdicated MONitor of EXotransits (DEMONEX) was a 20-inch robotic
and automated telescope to monitor bright stars hosting transiting
exoplanets to discover new planets and improve constraints on the
properties of known transiting planetary systems. We present results
for the misaligned hot Jupiter XO-4b containing seven new transits
from the DEMONEX telescope, including three full and four partial
transits. We combine these data with archival light curves and
archival radial velocity measurements to derive the host star mass
M*=1.293-0.029+0.030M☉ and radius
R*=1.554-0.030+0.042R☉, the planet mass
MP=1.615-0.099+0.10MJ and radius RP=1.317-0.029+0.040RJ,
and a refined ephemeris of P=4.1250687±0.0000024days and
T0=2454758.18978±0.00024BJDTDB. We include archival
Rossiter-McLaughlin measurements of XO-4 to infer the stellar
spin-planetary orbit alignment of λ=-40.0-7.5+8.8deg. We
test the effects of including various detrend parameters, theoretical
and empirical mass-radius relations, and Rossiter-McLaughlin models.
We infer that detrending against CCD position and time or airmass can
improve data quality but can have significant effects on the inferred
values of many parameters--most significantly Rp/R* and the
observed central transit times TC. In the case of Rp/R* we
find that the systematic uncertainty due to detrending can be three
times that of the quoted statistical uncertainties. The choice of
mass-radius relation has little effect on our inferred values of the
system parameters. The choice of Rossiter-McLaughlin models can have
significant effects on the inferred values of vsinI* and the
stellar spin-planet orbit angle λ.
Description:
New observations of XO-4b were made using DEdicated MONitor of
EXotransits (DEMONEX). DEMONEX monitored bright stars hosting known
transiting planets over a 3yr period from 2008 to 2011 in order to
provide a homogeneous data set of precise relative photometry for over
40 transiting systems.
There are 20 nights of data from 2008 November to 2010 May taken
during primary transits of XO-4b. All observations were made in the
Sloan z band.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s) (Period)
----------------------------------------------------------
07 21 33.17 +58 16 05.0 XO-4b = XO-4b (P=4.12506)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 67 1634 DEMONEX data
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See also:
J/A+A/552/A119 : Planet-star and moon-planet interaction (Saur+, 2013)
J/ApJ/766/9 : GALEX observations of exoplanet host stars (Shkolnik, 2013)
J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)
J/ApJ/757/18 : RVs for 16 hot Jupiter host stars (Albrecht+, 2012)
J/PASP/123/412 : Exoplanet Orbit Database (Wright+, 2011)
J/MNRAS/414/1278 : Eccentricities of transiting planets (Pont+, 2011)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "Y/M/D" Date UT Date of the observation
12- 25 F14.6 d BJDt Barycentric Julian Date in
Barycentric Dynamical Time
27- 34 F8.6 --- NFlux [0.98/1.02] Normalized flux
36- 43 F8.6 --- e_NFlux [0.001/0.02] Error in NFlux
45- 55 F11.6 pix XPix X pixel coordinate
57- 67 F11.6 pix YPix Y pixel coordinate
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 01-Jun-2016