J/ApJ/728/138 Follow-up photometry of HAT-P-26 (Hartman+, 2011)
HAT-P-26b: a low-density Neptune-mass planet transiting a K star.
Hartman J.D., Bakos G.A., Kipping D.M., Torres G., Kovacs G., Noyes R.W.,
Latham D.W., Howard A.W., Fischer D.A., Johnson J.A., Marcy G.W.,
Isaacson H., Quinn S.N., Buchhave L.A., Beky B., Sasselov D.D.,
Stefanik R.P., Esquerdo G.A., Everett M., Perumpilly G., Lazar J., Papp I.,
Sari P.
<Astrophys. J., 728, 138 (2011)>
=2011ApJ...728..138H 2011ApJ...728..138H
ADC_Keywords: Photometry, CCD ; Planets ; Stars, double and multiple
Keywords: planetary systems - stars: individual (HAT-P-26, GSC 0320-01027) -
techniques: photometric - techniques: spectroscopic
Abstract:
We report the discovery of HAT-P-26b, a transiting extrasolar planet
orbiting the moderately bright V=11.744 K1 dwarf star GSC 0320-01027,
with a period P=4.234516±0.000015 days, transit epoch
Tc=2455304.65122±0.00035 (BJD; Barycentric Julian dates throughout
the paper are calculated from Coordinated Universal Time (UTC)), and
transit duration 0.1023±0.0010 days. The host star has a mass of
0.82±0.03M☉, radius of 0.79+0.10-0.04R☉, effective
temperature 5079±88K, and metallicity [Fe/H]=-0.04±0.08. The
planetary companion has a mass of 0.059±0.007MJ, and radius of
0.565+0.072-0.032RJ yielding a mean density of
0.40±0.10g/cm3. HAT-P-26b is the fourth Neptune-mass transiting
planet discovered to date. It has a mass that is comparable to those
of Neptune and Uranus, and slightly smaller than those of the other
transiting Super-Neptunes, but a radius that is ∼65% larger than those
of Neptune and Uranus, and also larger than those of the other
transiting Super-Neptunes. HAT-P-26b is consistent with theoretical
models of an irradiated Neptune-mass planet with a 10M{earth} heavy
element core that comprises ≳50% of its mass with the remainder
contained in a significant hydrogen-helium envelope, though the exact
composition is uncertain as there are significant differences between
various theoretical models at the Neptune-mass regime. The equatorial
declination of the star makes it easily accessible to both Northern
and Southern ground-based facilities for follow-up observations.
Description:
We conducted follow-up photometric observations with the KeplerCam CCD
camera on the FLWO 1.2m telescope. We observed five transit events of
HAT-P-26 on the nights of 2010 January 5, March 31, April 4, May 8,
and May 25.
Objects:
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RA (2000) DE Designation(s) (Period)
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14 12 37.54 +04 03 36.1 HAT-P-26 = TYC 320-1027-1 (P=4.234516)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 39 1437 High-precision differential photometry of HAT-P-26
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See also:
B/eso : ESO Science Archive Catalog (ESO, 2012)
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2012)
J/MNRAS/422/2024 : X-age relation and exoplanet evaporation (Jackson+, 2012)
J/ApJ/694/1559 : Photometric follow-up of GJ 436b (Shporer+, 2009)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d BJD Baryocentric Julian Date (BJD-2400000)
13- 20 F8.5 mag mag Processed magnitude in Filter (1)
22- 28 F7.5 mag e_mag The 1σ error in mag
30- 37 F8.5 mag Omag Original magnitude in Filter (2)
39 A1 --- Filt [i] Filter used in the observation (i-band)
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Note (1): The out-of-transit level has been subtracted. These magnitudes have
been subjected to the EPD and TFA procedures, carried out
simultaneously with the transit fit.
Note (2): Raw magnitude values without application of the EPD and TFA
procedures.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-Sep-2012