J/ApJ/809/42 LC and RV data of PTFO 8-8695 T-Tauri star (Ciardi+, 2015)
Follow-up observations of PTFO 8-8695: a 3 Myr old T-Tauri star hosting
a Jupiter-mass planetary candidate.
Ciardi D.R., van Eyken J.C., Barnes J.W., Beichman C.A., Carey S.J.,
Crockett C.J., Eastman J., Johns-Krull C.M., Howell S.B., Kane S.R.,
Mclane J.N., Plavchan P., Prato L., Stauffer J., van Belle G.T.,
von Braun K.
<Astrophys. J., 809, 42 (2015)>
=2015ApJ...809...42C 2015ApJ...809...42C (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Photometry, infrared ; Radial velocities ; Photometry, RI ;
Planets
Keywords: planetary systems; stars: individual: (PTFO 8-8695,
2MASS J05250755+0134243, CVSO 30); stars: pre-main sequence
Abstract:
We present Spitzer 4.5µm light curve observations, Keck NIRSPEC
radial velocity observations, and LCOGT optical light curve
observations of PTFO 8-8695, which may host a Jupiter-sized planet in
a very short orbital period (0.45 days). Previous work by van Eyken et
al. (2012ApJ...755...42V 2012ApJ...755...42V) and Barnes et al. (2013ApJ...774...53B 2013ApJ...774...53B)
predicts that the stellar rotation axis and the planetary orbital
plane should precess with a period of 300-600 days. As a consequence,
the observed transits should change shape and depth, disappear, and
reappear with the precession. Our observations indicate the long-term
presence of the transit events (>3 years), and that the transits
indeed do change depth, disappear and reappear. The Spitzer
observations and the NIRSPEC radial velocity observations (with
contemporaneous LCOGT optical light curve data) are consistent with
the predicted transit times and depths for the M*=0.34M☉
precession model and demonstrate the disappearance of the transits. An
LCOGT optical light curve shows that the transits do reappear
approximately 1 year later. The observed transits occur at the times
predicted by a straight-forward propagation of the transit ephemeris.
The precession model correctly predicts the depth and time of the
Spitzer transit and the lack of a transit at the time of the NIRSPEC
radial velocity observations. However, the precession model predicts
the return of the transits approximately 1 month later than observed
by LCOGT. Overall, the data are suggestive that the planetary
interpretation of the observed transit events may indeed be correct,
but the precession model and data are currently insufficient to
confirm firmly the planetary status of PTFO 8-8695b.
Description:
Spitzer Space Telescope Director's discretionary time was granted to
observe PTFO 8-8695 on 2012 April 28 UT. The infrared observations of
PTFO 8-8695 consist of an 11.8hr stare at 4.5um with IRAC (request key
45476608).
Keck-II NIRSPEC observations were obtained on 2012 December 21 --a
full two years after the detection of the optical transits with PTF.
We obtained optical photometry for PTFO 8-8695 using the Las Cumbres
Observatory Global telescope Network (LCOGT) 1m telescope network
during 2012 December and 2013 November. We utilized the full network
capabilities of LCOGT including the sites at Cerro Tololo
Inter-American Observatory in Chile (CTIO), Siding Spring Observatory
in Australia (SSO), the South African Astronomical Observatory at
Sutherland, South Africa (SAAO), and McDonald Observatory in Texas
(MDO).
Objects:
--------------------------------------------------------------------
RA (ICRS) DE Designation(s)
--------------------------------------------------------------------
05 25 07.56 +01 34 24.3 PTFO 8-8695 = 2MASS J05250755+0134243
05 25 07.60 +01 34 24.3 PTFO 8-8695b = NAME PTFO 8-8695b
--------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 73 1370 Spitzer 4.5um light curve data
table2.dat 31 16 Keck NIRSPEC radial velocity data
table3.dat 87 515 Las Cumbres Observatory Global telescope
Network (LCOGT) r' light curve data
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/ApJ/784/45 : Kepler's multiple planet candidates. III. (Rowe+, 2014)
J/A+A/562/L3 : WASP-103b radial velocities and light curves (Gillon+, 2014)
J/ApJ/763/41 : Kepler multiple-candidate systems radii (Ciardi+, 2013)
J/ApJ/761/46 : HD 37605 radial velocities and photometry (Wang+, 2012)
J/AJ/142/60 : Palomar Transient Factory Orion Project (Van Eyken+, 2011)
J/ApJ/728/69 : Photoelectric photometry of V410 Tauri (Rice+, 2011)
J/AJ/141/50 : White-light flares on cool Kepler stars (Walkowicz+, 2011)
J/ApJ/671/1784 : Ori OB1 IRAC/MIPS observations (Hernandez+, 2007)
J/ApJ/661/1119 : Spectroscopy in the 25 Ori group (Briceno+, 2007)
J/AJ/129/907 : New Ori OB1 members (Briceno+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d BJD Barycentic Julian Date
15- 21 F7.4 --- Phase Phase
23- 31 F9.7 --- OFlux [0.97/1.38] Normalized Spitzer/IRAC 4.5 micron
band flux
33- 41 F9.7 --- e_OFlux [0.003/0.04] Uncertainty in OFlux
43- 51 F9.7 --- MFlux [0.99/1.006] Normalized stellar model flux
53- 62 F10.7 --- O-M [-0.03/0.4] Difference between the observed and
model fluxes
64- 73 F10.7 --- Trans [-0.006/0] Transit model difference to model
subtracted fluxes
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.3 --- HJD Heliocentric Julian Date of the observation
13- 18 F6.3 --- Phase [-0.3/0.3] Phase
20- 25 F6.3 km/s RV [-2.8/1.4] Radial velocity
27- 31 F5.3 km/s e_RV [0.8/2.4] RV uncertainty
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 "Y/M" Date UT date of the observation
15- 27 F13.5 d BJD Barycentic Julian Date of observation
29- 35 F7.4 --- Phase Phase
37- 45 F9.7 --- OFlux [0.91/1.24] Normalized LCOGT r' band flux
47- 55 F9.7 --- e_OFlux [0.003/0.006] Uncertainty in OFlux
57- 65 F9.7 --- MFlux [0.92/1.25] Normalized stellar model flux
67- 76 F10.7 --- O-M [-0.04/0.03] Difference between the observed
and model fluxes
78- 87 F10.7 --- Trans [-0.03/0]? Transit model difference to model
subtracted fluxes
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Dec-2015