J/AJ/152/136 Follow-up photometry and spectroscopy of KELT-17 (Zhou+, 2016)
KELT-17b: a hot-Jupiter transiting an a-star in a misaligned orbit detected with
Doppler tomography.
Zhou G., Rodriguez J.E., Collins K.A., Beatty T., Oberst T., Heintz T.M.,
Stassun K.G., Latham D.W., Kuhn R.B., Bieryla A., Lund M.B.,
Labadie-Bartz J., Siverd R.J., Stevens D.J., Gaudi B.S., Pepper J.,
Buchhave L.A., Eastman J., Colon K., Cargile P., James D., Gregorio J.,
Reed P.A., Jensen E.L.N., Cohen D.H., McLeod K.K., Tan T.G., Zambelli R.,
Bayliss D., Bento J., Esquerdo G.A., Berlind P., Calkins M.L., Blancato K.,
Manner M., Samulski C., Stockdale C., Nelson P., Stephens D., Curtis I.,
Kielkopf J., Fulton B.J., DePoy D.L., Marshall J.L., Pogge R., Gould A.,
Trueblood M., Trueblood P.
<Astron. J., 152, 136-136 (2016)>
=2016AJ....152..136Z 2016AJ....152..136Z (SIMBAD/NED BibCode)
ADC_Keywords: Planets ; Stars, double and multiple ; Photometry, UBVRI ;
Photometry, ugriz ; Radial velocities
Keywords: planets and satellites: individual: KELT-17b -
stars: individual: (KELT-17,BD+14 1881,TYC 807-903-1)
Abstract:
We present the discovery of a hot Jupiter transiting the V=9.23mag
main-sequence A-star KELT-17 (BD+14 1881). KELT-17b is a
1.31-0.29+0.28MJ, 1.525-0.060+0.065RJ hot-Jupiter in a
3.08-day period orbit misaligned at -115.9°±4.1° to the
rotation axis of the star. The planet is confirmed via both the
detection of the radial velocity orbit, and the Doppler tomographic
detection of the shadow of the planet during two transits. The nature
of the spin-orbit misaligned transit geometry allows us to place a
constraint on the level of differential rotation in the host star; we
find that KELT-17 is consistent with both rigid-body rotation and
solar differential rotation rates (α<0.30 at 2σ
significance). KELT-17 is only the fourth A-star with a confirmed
transiting planet, and with a mass of 1.635-0.061+0.066M☉,
an effective temperature of 7454±49K, and a projected rotational
velocity of vsinI*=44.2-1.3+1.5km/s; it is among the most
massive, hottest, and most rapidly rotating of known planet hosts.
Description:
KELT-17, the first exoplanet host discovered through the combined
observations of both the Kilodegree Extremely Little Telescope
(KELT)-North and KELT-South, is located in KELT-South field 06 (KS06)
and KELT-North field 14 (KN14), which are both centered on
α=07h39m36s δ=+03°00'00'' (J2000). At the time
of identification, the post-processed KELT data set included 2092
images from KN14, taken between UT 2011 October 11 and UT 2013 March
26 and 2636 images from KS06 taken between UT 2010 March 02 and 2013
May 10. The discovery light curves from both KELT-North and KELT-South
are shown in Figure1.
We obtained higher spatial resolution and precision photometric
follow-up observations of KELT-17b in multiple filters.
An I-band transit was observed on UT 2015 March 05 at the Canela's
Robotic Observatory (CROW) with the 0.3m SCT12 telescope, remotely
operated from Portalegre, Portugal. Observations were acquired with
the ST10XME CCD camera, with a 30'*20' field of view and a 0.86''
pixel scale.
A full multi-color (V and I) transit of KELT-17b was observed on UT
2015 March 12 at Kutztown University Observatory (KUO), located on the
campus of Kutztown University in Kutztown, Pennsylvania. KUO's main
instrument is the 0.6 m Ritchey-Chretien optical telescope with a
focal ratio of f/8. The imaging CCD (KAF-6303E) camera has an array of
3K*2K (9µm) pixels and covers a field of view of 19.5'*13.0'.
The Peter van de Kamp Observatory (PvdK) at Swarthmore College (near
Philadelphia) houses a 0.62m Ritchey-Chretien reflector with a 4K*4K
pixel Apogee CCD. The telescope and camera together have a 26'*26'
field of view and a 0.61'' pixel scale. PvdK observed KELT-17b on UT
2015 March 12 in the SDSS z' filter.
KELT-17b was observed in both g' and i' on UT 2015 March 12 at
Wellesley College's Whitin Observatory in Massachusetts. The telescope
is a 0.6m Boller and Chivens with a DFM focal reducer yielding an
effective focal ratio of f/9.6. We used an Apogee U230 2K*2K camera
with a 0.58''/pixel scale and a 20'*20' field of view.
One full transit of KELT-17b was observed from the Westminster College
Observatory (WCO), PA, on UT 2015 November 4 in the z' filter. The
observations employed a 0.35m f/11 Celestron C14 Schmidt-Cassegrain
telescope and SBIG STL-6303E CCD with a ∼3K*2K array of 9µm pixels,
yielding a 24'*16' field of view and 1.4''/pixel image scale at 3*3
pixel binning. The stellar FWHM was seeing-limited with a typical
value of ∼3.2''.
Three full transits of KELT-17b were observed on UT 2016 February 26
(g' and i') and UT 2016 March 31 (r') using the Manner-Vanderbilt
Ritchie-Chrtien (MVRC) telescope located at the Mt. Lemmon summit of
Steward Observatory, AZ. The observations employed a 0.6m f/8 RC
Optical Systems Ritchie-Chretien telescope and SBIG STX-16803 CCD with
a 4K*4K array of 9µm pixels, yielding a 26'*26' field of view and
0.39''/pixel image scale. The telescope was heavily defocused for all
three observations resulting in a typical stellar FWHM of ∼17''.
The Perth Exoplanet Survey Telescope (PEST) observatory is a backyard
observatory owned and operated by ThiamGuan (TG) Tan, located in
Perth, Australia. It is equipped with a 0.3m Meade LX200 SCT f/10
telescope with focal reducer yielding f/5 and an SBIG ST-8XME CCD
camera. The telescope and camera combine to have a 31'*21' field of
view and a 1.2'' pixel scale. PEST observed KELT-17b on UT 2016 March
06 in the B band.
A series of spectroscopic follow-up observations were performed to
characterize the KELT-17 system. We performed low-resolution,
high-signal-to-noise reconnaissance spectroscopic follow-up of KELT-17
using the Wide Field Spectrograph (WiFeS) on the Australian National
University (ANU) 2.3m telescope at Siding Spring Observatory,
Australia in 2015 February. In-depth spectroscopic characterization of
KELT-17 was performed by the Tillinghast Reflector Echelle
Spectrograph (TRES) on the 1.5m telescope at the Fred Lawrence Whipple
Observatory, Mount Hopkins, Arizona, USA. TRES has a wavelength
coverage of 3900-9100Å over 51 echelle orders, with a resolving
power of λ/Δλ R=44000. A total of 12
out-of-transit observations were taken to characterize the radial
velocity orbital variations exhibited by KELT-17. In addition, we also
observed spectroscopic transits of KELT-17b with TRES on 2016 February
23 and 2016 February 26 UT, gathering 33 and 29 sets of spectra,
respectively.
Objects:
------------------------------------------------------------------
RA (ICRS) DE Designation(s) (Period)
------------------------------------------------------------------
08 22 28.21 +13 44 07.2 KELT-17 = BD+14 1881 (P=3.0801718)
------------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
figure1.dat 41 4728 Discovery light curves from the Kilodegree
Extremely Little Telescope (KELT) survey
figure2.dat 37 1491 The individual KELT follow-up network
observations of KELT-17b
table5.dat 34 74 Relative radial velocities for KELT-17
table6.dat 43 11 Transit times for KELT-17b
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See also:
B/vsx : AAVSO International Variable Star Index (Watson+, 2006-2014)
J/AJ/150/32 : KELT photometry of V409 Tau and AA Tau (Rodriguez+, 2015)
J/AJ/150/12 : Radial velocity of HD 33643 (Bieryla+, 2015)
J/AJ/146/113 : Differential griz photometry of HATS-3 (Bayliss+, 2013)
J/ApJ/761/123 : KELT-1 photometry and spectroscopy follow-up (Siverd+, 2012)
J/ApJ/720/1118 : i-band photometry of HAT-P-16 (Buchhave+, 2010)
Byte-by-byte Description of file: figure1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 F24.16 d BJD Barycentric Julian Date (TDB)
26- 33 F8.5 --- mag [12.08/12.15] KELT survey magnitude
35- 41 F7.5 --- e_mag [0.00085/0.025] Uncertainty in mag
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Byte-by-byte Description of file: figure2.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD Barycentric Julian Date (TDB) (1)
16- 21 F6.4 --- Flux [0.9794/1.011] Relative flux
23- 28 F6.4 --- e_Flux [0.0004/0.003] Uncertainty in Flux
30- 35 A6 --- Inst Instrument used (CROW, KUO, MVRC, PEST, Pvdk,
WCO, or Whitin) (G1)
37 A1 --- Flt [BVIgriz] Filter used (B, V, I, g, r, i, or z)
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Note (1): We carefully ensured that all follow-up observations were correctly
converted to BJDTDB (Eastman et al. 2010PASP..122..935E 2010PASP..122..935E).
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- f_BJD [a] Flag on BJD (1)
2- 14 F13.5 d BJD UTC Barycentric Julian Date
16- 19 I4 m/s RV [-261/423] Relative radial velocity
20 A1 --- f_RV [c] Template exposure defined as 0.0m/s
22- 24 I3 m/s e_RV [53/185] Error in RV
26- 28 I3 s Exp [300/900] Exposure time
30- 34 F5.1 --- S/N [45/136] Signal-to-noise per resolution element (2)
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Note (1): Exposures used to derive the Doppler tomographic transit signal, which
was then used in the global EXOFAST analysis. In-transit velocities for the
Rossiter-McLaughlin effect were not used in the EXOFAST analysis.
Note (2): Signal-to-noise per resolution element of the spectrum over the Mg b
line region.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- E [-45/82] Epoch
5- 18 F14.6 d Tc Time of inferior conjunction (TC) in
Barycentric Julian Date (BJDTDB)
20- 22 I3 s e_Tc [53/155] Uncertainty in Tc (σTc)
24- 30 F7.2 s O-C1 [-213/289] Transit time residual
32- 36 F5.2 s O-C2 [-2.2/2] The (O-C) value for σTc
38- 43 A6 --- Tel Telescope (CROW, KUO, MVRC, PEST, Pvdk, WCO,
Whitin) (G1)
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Global Notes:
Note (G1): The instruments used are defined as follows:
CROW = Canela's Robotic Observatory (CROW) with the 0.3m SCT12 telescope,
remotely operated from Portalegre, Portugal;
KUO = Kutztown University Observatory (KUO), located on the campus of
Kutztown University in Kutztown, Pennsylvania;
MVRC = Manner-Vanderbilt Ritchie-Chrtien (MVRC) telescope located at the
Mt. Lemmon summit of Steward Observatory, AZ;
PEST = Perth Exoplanet Survey Telescope (PEST) observatory, a backyard
observatory owned and operated by ThiamGuan (TG) Tan, located in
Perth, Australia;
Pvdk = Peter van de Kamp Observatory (PvdK) at Swarthmore College (near
Philadelphia);
WCO = Westminster College Observatory (WCO), PA;
Whitin = Wellesley College's Whitin Observatory in Massachusetts.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 26-May-2017