-
W. J. Borucki,
E. Agol,
F. Fressin,
L. Kaltenegger,
J. Rowe,
H. Isaacson,
D. Fischer,
N. Batalha,
J. J. Lissauer,
G. W. Marcy, [......],
S. Seader,
A. Shporer,
J. H. Steffen,
M. Still,
P. Tenenbaum,
S. E. Thompson, G. Torres,
J. D. Twicken,
W. F. Welsh,
J. N. Winn
[show abstract]
[hide abstract]
ABSTRACT: We present the detection of five planets -- Kepler-62b, c, d, e, and f -- of
size 1.31, 0.54, 1.95, 1.61 and 1.41 Earth radii, orbiting a K2V star at
periods of 5.7, 12.4, 18.2, 122.4 and 267.3 days, respectively. The outermost
planets (Kepler-62e & -62f) are super-Earth-size (1.25 < planet radius/earth
radius < 2.0) planets in the habitable zone (HZ) of their host star, receiving
1.2 +- 0.2 and 0.41 +- 0.05 times the solar flux at Earth's orbit. Theoretical
models of Kepler-62e and -62f for a stellar age of ~7 Gyr suggest that both
planets could be solid: either with a rocky composition or composed of mostly
solid water in their bulk.
04/2013;
-
I. Boisse,
J. Hartman,
G. Bakos,
K. Penev,
Z. Csubry,
B. Beky,
D. Latham,
A. Bieryla, G. Torres,
G. Kovacs, [......],
G. Esquerdo,
T. Szklenar,
E. Falco,
A. Shporer,
B. Fulton,
R. Noyes,
R. Stefanik,
J. Lazar,
I. Papp,
P. Sari
[show abstract]
[hide abstract]
ABSTRACT: First identified from the HATNet wide-field photometric survey, these
candidate transiting planets were then followed-up with a variety of
photometric observations. Determining the planetary nature of the objects and
characterizing the parameters of the systems were mainly done with the SOPHIE
spectrograph at the 1.93m telescope at OHP and the TRES spectrograph at the
1.5m telescope at FLWO. HAT-P-42b and HAT-P-43b are typical hot Jupiters on
circular orbits around early-G/late-F main sequence host stars, with periods of
4.641876\pm0.000032 and 3.332688\pm0.000016 days, masses of 0.975\pm0.126 and
0.660\pm0.083 Mjup, and radii of 1.277\pm0.149 and 1.283+0.057-0.034 Rjup,
respectively. These discoveries increase the sample of planets with measured
mean densities, which is needed to constrain theories of planetary interiors
and atmospheres. Moreover, their hosts are relatively bright (V < 13.5)
facilitating further follow-up studies.
12/2012;
-
J. D. Hartman,
G. Á. Bakos,
B. Béky, G. Torres,
D. W. Latham,
Z. Csubry,
K. Penev,
A. Shporer,
B. J. Fulton,
L. A. Buchhave, [......],
S. N. Quinn,
A. Bieryla,
R. P. Knox,
P. Hinz,
D. D. Sasselov,
G. Fűrész,
R. P. Stefanik,
J. Lázár,
I. Papp,
P. Sári
[show abstract]
[hide abstract]
ABSTRACT: We report the discovery of three new transiting extrasolar planets orbiting
moderately bright (V=11.1 to 12.4) F stars. The planets have periods of P =
2.6940 d to 4.4572 d, masses of 0.60 M_J to 0.80 M_J, and radii of 1.57 R_J to
1.73 R_J. They orbit stars with masses between 1.40 M_sun and 1.51 M_sun. The
three planets are members of an emerging population of highly inflated Jupiters
with 0.4 M_J < M < 1.5 M_J and R > 1.5 R_J.
07/2012;
-
S. N. Quinn,
R. J. White,
D. W. Latham,
L. A. Buchhave,
J. R. Cantrell,
S. E. Dahm,
G. Fürész,
A. H. Szentgyorgyi,
J. C. Geary, G. Torres,
A. Bieryla,
P. Berlind,
M. C. Calkins,
G. A. Esquerdo,
R. P. Stefanik
[show abstract]
[hide abstract]
ABSTRACT: We present the discovery of two giant planets orbiting stars in Praesepe
(also known as the Beehive Cluster). These are the first known hot Jupiters in
an open cluster and the only planets known to orbit Sun-like, main-sequence
stars in a cluster. The planets are detected from Doppler shifted radial
velocities; line bisector spans and activity indices show no correlation with
orbital phase, confirming the variations are caused by planetary companions.
Pr0201b orbits a V=10.52 late F dwarf with a period of 4.4264 +/- 0.0070 days
and has a minimum mass of 0.540 +/- 0.039 Mjup, and Pr0211b orbits a V=12.06
late G dwarf with a period of 2.1451 +/- 0.0012 days and has a minimum mass of
1.844 +/- 0.064 Mjup. The detection of 2 planets among 53 single members
surveyed establishes a lower limit on the hot Jupiter frequency of 3.8
(+5.0)(-2.4) % in this metal-rich open cluster. Given the precisely known age
of the cluster, this discovery also demonstrates that, in at least 2 cases,
giant planet migration occurred within 600 Myr after formation. As we endeavor
to learn more about the frequency and formation history of planets,
environments with well-determined properties -- such as open clusters like
Praesepe -- may provide essential clues to this end.
07/2012;
-
D Limonta,
V Falcón, G Torres,
V Capó,
I Menéndez,
D Rosario,
Y Castellanos,
M Alvarez,
R Rodríguez-Roche,
M C de la Rosa,
A Pavón,
L López,
K González,
G Guillén,
J Diaz,
M G Guzmán
[show abstract]
[hide abstract]
ABSTRACT: Dengue virus is the most significant virus transmitted by arthropods worldwide and may cause a potentially fatal systemic disease named dengue hemorrhagic fever. In this work, dengue virus serotype 4 was detected in the tissues of one fatal dengue hemorrhagic fever case using electron immunomicroscopy and molecular methods. This is the first report of dengue virus polypeptides findings by electron immunomicroscopy in human samples. In addition, not-previously-documented virus-like particles visualized in spleen, hepatic, brain, and pulmonary tissues from a dengue case are discussed.
Infection 04/2012; · 2.66 Impact Factor
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S B Howell,
J F Rowe,
S T Bryson,
S N Quinn,
G W Marcy,
H Isaacson,
D R Ciardi,
W J Chaplin,
T S Metcalfe,
Mjpfg Monteiro, [......],
J L Christiansen,
C K Middour,
M R Haas,
J R Hall,
J M Jenkins,
S McCaulif,
M N Fanelli,
C Kulesa,
D McCarthy,
C E Henze
[show abstract]
[hide abstract]
ABSTRACT: We present Kepler observations of the bright (V = 8.3), oscillating star HD 179070. The observations show transit-like events which reveal that the star is orbited every 2.8 days by a small, 1.6 R-Earth object. Seismic studies of HD 179070 using short cadence Kepler observations show that HD 179070 has a frequency-power spectrum consistent with solar-like oscillations that are acoustic p-modes. Asteroseismic analysis provides robust values for the mass and radius of HD 179070, 1.34 +/- 0.06 M-circle dot and 1.86 +/- 0.04 R-circle dot, respectively, as well as yielding an age of 2.84 +/- 0.34 Gyr for this F5 subgiant. Together with ground-based follow-up observations, analysis of the Kepler light curves and image data, and blend scenario models, we conservatively show at the >99.7% confidence level (3 sigma) that the transit event is caused by a 1.64 +/- 0.04 R-Earth exoplanet in a 2.785755 +/- 0.000032 day orbit. The exoplanet is only 0.04 AU away from the star and our spectroscopic observations provide an upper limit to its mass of similar to 10 M-Earth (2 sigma). HD 179070 is the brightest exoplanet host star yet discovered by Kepler.
The Astrophysical Journal 02/2012; 746:123 (18pp). · 6.02 Impact Factor
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G. Á. Bakos,
J. D. Hartman, G. Torres,
B. Béky,
D. W. Latham,
L. A. Buchhave,
Z. Csubry,
G. Kovács,
A. Bieryla,
S. Quinn, [......],
G. W. Marcy,
B. Sato,
K. Penev,
M. Everett,
D. D. Sasselov,
G. Fürész,
R. P. Stefanik,
J. Lázár,
I. Papp,
P. Sári
[show abstract]
[hide abstract]
ABSTRACT: We report the discovery of four transiting extrasolar planets (HAT-P-34b -
HAT-P-37b) with masses ranging from 1.05 to 3.33 MJ and periods from 1.33 to
5.45 days. These planets orbit relatively bright F and G dwarf stars (from V =
10.16 to V = 13.2). Of particular interest is HAT-P-34b which is moderately
massive (3.33 MJ), has a high eccentricity of e = 0.441 +/- 0.032 at P =
5.4526540+/-0.000016 d period, and shows hints of an outer component. The other
three planets have properties that are typical of hot Jupiters.
01/2012;
-
S. N. Quinn,
G. Á. Bakos,
J. Hartman, G. Torres,
G. Kovács,
D. W. Latham,
R. W. Noyes,
D. A. Fischer,
J. A. Johnson,
G. W. Marcy, [......],
G. Fűrész,
L. A. Buchhave,
B. Béky,
D. D. Sasselov,
R. P. Stefanik,
G. Perumpilly,
M. Everett,
J. Lázár,
I. Papp,
and P. Sári
[show abstract]
[hide abstract]
ABSTRACT: We report the discovery of HAT-P-25b, a transiting extrasolar planet orbiting the V = 13.19 G5 dwarf star GSC 1788-01237, with a period P = 3.652836 ± 0.000019 days, transit epoch Tc = 2455176.85173 ± 0.00047 (BJD—barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time, UTC), and transit duration 0.1174 ± 0.0017 days. The host star has a mass of 1.01 ± 0.03 M ☉, radius of 0.96+0.05 – 0.04 R ☉, effective temperature 5500 ± 80 K, and metallicity [Fe/H] = +0.31 ± 0.08. The planetary companion has a mass of 0.567 ± 0.022 M J and radius of 1.190+0.081 – 0.056 R J yielding a mean density of 0.42 ± 0.07 g cm–3.
The Astrophysical Journal 12/2011; 745(1):80. · 6.02 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: CONTEXT: Accurate physical properties of eclipsing stars provide important
constraints on models of stellar structure and evolution, especially when
combined with spectroscopic information on their chemical composition.
Empirical calibrations of the data also lead to accurate mass and radius
estimates for exoplanet host stars. Finally, accurate data for unusual stellar
subtypes, such as Am stars, also help to unravel the cause(s) of their
peculiarities. AIMS: We aim to determine the masses, radii, effective
temperatures, detailed chemical composition and rotational speeds for the
Am-type eclipsing binaries SW CMa (A4-5m) and HW CMa (A6m) and compare them
with similar normal stars. METHODS: Accurate radial velocities from the Digital
Speedometers of the Harvard-Smithsonian Center for Astrophysics were combined
with previously published uvby photometry to determine precise physical
parameters for the four stars. A detailed abundance analysis was performed from
high-resolution spectra obtained with the Nordic Optical Telescope (La Palma).
RESULTS: We find the masses of the (relatively evolved) stars in SW CMa to be
2.10 and 2.24 solar masses, with radii of 2.50 and 3.01 solar radii, while the
(essentially zero-age) stars in HW CMa have masses of 1.72 and 1.78 solar
masses, radii of 1.64 and 1.66 solar radii -- all with errors well below 2%.
Detailed atmospheric abundances for one or both components were determined for
14 elements in SW CMa ([Fe/H] = +0.49/+0.61 dex) and 16 in HW CMa ([Fe/H] =
+0.33/+0.32 dex); both abundance patterns are characteristic of metallic-line
stars. Both systems are well fit by current stellar evolution models for
assumed bulk abundances of [Fe/H] = +0.05 and +0.23, respectively ([alpha/Fe] =
0.0), and ages of about 700 Myr and 160 Myr.
12/2011;
-
G. Torres,
H. Levato,
C. Lovis,
G. W. Marcy,
R. D. Mathieu,
T. Mazeh,
S. Meibom,
D. Minniti,
C. Moutou,
F. Pepe,
D. Pourbaix,
C. Turon,
S. Udry,
T. Zwitter
[show abstract]
[hide abstract]
ABSTRACT: Brief summaries are given of the following subjects of interest to IAU
Commission 30: Large-scale radial-velocity surveys; The role of radial-velocity
measurements in studies of stellar angular momentum evolution and stellar age;
Radial velocities in open clusters; Toward higher radial-velocity precision;
High-precision radial velocities applied to studies of binary stars; Doppler
boosting effect; Working groups (Stellar radial velocity bibliography; Radial
velocity standards; Catalogue of orbital elements of spectroscopic binaries
[SB9]).
12/2011;
-
G. Á. Bakos,
J. Hartman, G. Torres,
D. W. Latham,
Géza Kovács,
R. W. Noyes,
D. A. Fischer,
J. A. Johnson,
G. W. Marcy,
A. W. Howard, [......],
A. Shporer,
B. Béky,
L. A. Buchhave,
G. Perumpilly,
M. Everett,
D. D. Sasselov,
R. P. Stefanik,
J. Lázár,
I. Papp,
and P. Sári
[show abstract]
[hide abstract]
ABSTRACT: We report the discovery of four relatively massive (2-7 M J) transiting extrasolar planets. HAT-P-20b orbits the moderately bright V = 11.339 K3 dwarf star GSC 1910-00239 on a circular orbit, with a period P = 2.875317 ± 0.000004 days, transit epoch Tc = 2455080.92661 ± 0.00021 (BJDUTC), and transit duration 0.0770 ± 0.0008 days. The host star has a mass of 0.76 ± 0.03 M ☉, radius of 0.69 ± 0.02 R ☉, effective temperature 4595 ± 80 K, and metallicity [Fe/H] = +0.35 ± 0.08. The planetary companion has a mass of 7.246 ± 0.187 M J and a radius of 0.867 ± 0.033 R J yielding a mean density of 13.78 ± 1.50 g cm–3. HAT-P-21b orbits the V = 11.685 G3 dwarf star GSC 3013-01229 on an eccentric (e = 0.228 ± 0.016) orbit, with a period P = 4.124481 ± 0.000007 days, transit epoch Tc = 2454996.41312 ± 0.00069, and transit duration 0.1530 ± 0.0027 days. The host star has a mass of 0.95 ± 0.04 M ☉, radius of 1.10 ± 0.08 R ☉, effective temperature 5588 ± 80 K, and metallicity [Fe/H] = +0.01 ± 0.08. The planetary companion has a mass of 4.063 ± 0.161 M J and a radius of 1.024 ± 0.092 R J yielding a mean density of 4.68+1.59 – 0.99 g cm–3. HAT-P-21b is a borderline object between the pM and pL class planets, and the transits occur near apastron. HAT-P-22b orbits the bright V = 9.732 G5 dwarf star HD 233731 on a circular orbit, with a period P = 3.212220 ± 0.000009 days, transit epoch Tc = 2454930.22001 ± 0.00025, and transit duration 0.1196 ± 0.0014 days. The host star has a mass of 0.92 ± 0.03 M ☉, radius of 1.04 ± 0.04 R ☉, effective temperature 5302 ± 80 K, and metallicity [Fe/H] = +0.24 ± 0.08. The planet has a mass of 2.147 ± 0.061 M J and a compact radius of 1.080 ± 0.058 R J yielding a mean density of 2.11+0.40 – 0.29 g cm–3. The host star also harbors an M-dwarf companion at a wide separation. Finally, HAT-P-23b orbits the V = 12.432 G0 dwarf star GSC 1632-01396 on a close to circular orbit, with a period P = 1.212884 ± 0.000002 days, transit epoch Tc = 2454852.26464 ± 0.00018, and transit duration 0.0908 ± 0.0007 days. The host star has a mass of 1.13 ± 0.04 M ☉, radius of 1.20 ± 0.07 R ☉, effective temperature 5905 ± 80 K, and metallicity [Fe/H] = +0.15 ± 0.04. The planetary companion has a mass of 2.090 ± 0.111 M J and a radius of 1.368 ± 0.090 R J yielding a mean density of 1.01 ± 0.18 g cm–3. HAT-P-23b is an inflated and massive hot Jupiter on a very short period orbit, and has one of the shortest characteristic infall times (7.5+2.9 – 1.8 Myr) before it gets engulfed by the star.
The Astrophysical Journal 11/2011; 742(2):116. · 6.02 Impact Factor
-
AAS/Division for Extreme Solar Systems Abstracts; 09/2011
-
R. Neuhäuser,
R. Errmann,
A. Berndt,
G. Maciejewski,
H. Takahashi,
W.P. Chen,
D.P. Dimitrov,
T. Pribulla,
E.H. Nikogossian,
E.L.N. Jensen, [......],
E. Schmidt,
M.M. Hohle,
M. Kitze,
N. Chakrova,
C. Gräfe,
K. Schreyer,
V.V. Hambaryan,
C.H. Broeg,
J. Koppenhoefer,
A.K. Pandey
[show abstract]
[hide abstract]
ABSTRACT: We present the Young Exoplanet Transit Initiative (YETI), in which we use several 0.2 to 2.6-m telescopes around the world to monitor continuously young (≤100 Myr), nearby (≤1 kpc) stellar clusters mainly to detect young transiting planets (and to study other variability phenomena on time-scales from minutes to years). The telescope network enables us to observe the targets continuously for several days in order not to miss any transit. The runs are typically one to two weeks long, about three runs per year per cluster in two or three subsequent years for about ten clusters. There are thousands of stars detectable in each field with several hundred known cluster members, e.g. in the first cluster observed, Tr-37, a typical cluster for the YETI survey, there are at least 469 known young stars detected in YETI data down to R = 16.5 mag with sufficient precision of 50 millimag rms (5 mmag rms down to R = 14.5 mag) to detect transits, so that we can expect at least about one young transiting object in this cluster. If we observe ∼10 similar clusters, we can expect to detect ∼10 young transiting planets with radius determinations. The precision given above is for a typical telescope of the YETI network, namely the 60/90-cm Jena telescope (similar brightness limit, namely within ±1 mag, for the others) so that planetary transits can be detected. For targets with a periodic transit-like light curve, we obtain spectroscopy to ensure that the star is young and that the transiting object can be sub-stellar; then, we obtain Adaptive Optics infrared images and spectra, to exclude other bright eclipsing stars in the (larger) optical PSF; we carry out other observations as needed to rule out other false positive scenarios; finally, we also perform spectroscopy to determine the mass of the transiting companion. For planets with mass and radius determinations, we can calculate the mean density and probe the internal structure. We aim to constrain planet formation models and their time-scales by discovering planets younger than ∼100 Myr and determining not only their orbital parameters, but also measuring their true masses and radii, which is possible so far only by the transit method. Here, we present an overview and first results (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Astronomische Nachrichten 06/2011; 332(6):547 - 561. · 1.01 Impact Factor
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J. H. Steffen,
S. N. Quinn,
W. J. Borucki,
E. Brugamyer,
S. T. Bryson,
L. A. Buchhave,
W. D. Cochran,
M. Endl,
D. C. Fabrycky,
E. B. Ford, [......],
J. F. Rowe,
D. T. Sanderfer,
S. E. Seader,
D. Short,
A. Shporer,
S. E. Thompson, G. Torres,
J. D. Twicken,
W. F. Welsh,
G. Windmiller
[show abstract]
[hide abstract]
ABSTRACT: We present a hierarchical triple star system (KIC 9140402) where a low mass
eclipsing binary orbits a more massive third star. The orbital period of the
binary (4.98829 Days) is determined by the eclipse times seen in photometry
from NASA's Kepler spacecraft. The periodically changing tidal field, due to
the eccentric orbit of the binary about the tertiary, causes a change in the
orbital period of the binary. The resulting eclipse timing variations provide
insight into the dynamics and architecture of this system and allow the
inference of the total mass of the binary ($0.424 \pm 0.017 \text{M}_\odot$)
and the orbital parameters of the binary about the central star.
06/2011;
-
R. Neuhäuser,
R. Errmann,
A Berndt,
G. Maciejewski,
H Takahashi,
W P Chen,
D. P. Dimitrov,
T. Pribulla,
E. H. Nikogossian,
E. L. N. Jensen, [......],
E Schmidt,
M. M. Hohle,
M. Kitze,
N. Chakrova,
C. Gräfe,
K. Schreyer,
V. V. Hambaryan,
C. H. Broeg,
J. Koppenhoefer,
A. K. Pandey
[show abstract]
[hide abstract]
ABSTRACT: We present the Young Exoplanet Transit Initiative (YETI), in which we use
several 0.2 to 2.6m telescopes around the world to monitor continuously young
(< 100 Myr), nearby (< 1 kpc) stellar clusters mainly to detect young
transiting planets (and to study other variability phenomena on time-scales
from minutes to years). The telescope network enables us to observe the targets
continuously for several days in order not to miss any transit. The runs are
typically one to two weeks long, about three runs per year per cluster in two
or three subsequent years for about ten clusters. There are thousands of stars
detectable in each field with several hundred known cluster members, e.g. in
the first cluster observed, Tr-37, a typical cluster for the YETI survey, there
are at least 469 known young stars detected in YETI data down to R=16.5 mag
with sufficient precision of 50 milli-mag rms (5 mmag rms down to R=14.5 mag)
to detect transits, so that we can expect at least about one young transiting
object in this cluster. If we observe 10 similar clusters, we can expect to
detect approximately 10 young transiting planets with radius determinations.
The precision given above is for a typical telescope of the YETI network,
namely the 60/90-cm Jena telescope (similar brightness limit, namely within
+/-1 mag, for the others) so that planetary transits can be detected. For
planets with mass and radius determinations, we can calculate the mean density
and probe the internal structure. We aim to constrain planet formation models
and their time-scales by discovering planets younger than 100 Myr and
determining not only their orbital parameters, but also measuring their true
masses and radii, which is possible so far only by the transit method. Here, we
present an overview and first results. (Abstract shortened)
06/2011;
-
J. D. Hartman,
G. Á. Bakos, G. Torres,
D. W. Latham,
G. Kovács,
B. Béky,
S. N. Quinn,
T. Mazeh,
A. Shporer,
G. W. Marcy, [......],
J A Johnson,
G. A. Esquerdo,
R. W. Noyes,
D. D. Sasselov,
R. P. Stefanik,
J. M. Fernandez,
T. Szklenár,
J. Lázár,
I. Papp,
P. Sári
[show abstract]
[hide abstract]
ABSTRACT: We report the discovery of two exoplanets transiting high-jitter stars.
HAT-P-32b orbits the bright V=11.289 star GSC 3281-00800, with a period P =
2.150008 d. The stellar and planetary masses and radii depend on the
eccentricity of the system, which is poorly constrained due to the high
velocity jitter (~80m/s). Assuming a circular orbit, the star has a mass of
1.16+-0.04 M_sun, and radius of 1.22+-0.02 R_sun, while the planet has a mass
of 0.860+-0.164 MJ, and a radius of 1.789+-0.025 RJ. When the eccentricity is
allowed to vary, the best-fit model results in a planet which is close to
filling its Roche Lobe. Including the constraint that the planet cannot exceed
its Roche Lobe results in the following best-fit parameters: e = 0.163+-0.061,
Mp = 0.94+-0.17 MJ, Rp = 2.04+-0.10 RJ, Ms = 1.18+0.04-0.07 M_sun and Rs =
1.39+-0.07 R_sun. The second planet, HAT-P-33b, orbits the bright V=11.188 star
GSC 2461-00988, with a period P = 3.474474 d. As for HAT-P-32, the stellar and
planetary masses and radii of HAT-P-33 depend on the eccentricity, which is
poorly constrained due to the high jitter (~50m/s). In this case spectral line
bisector spans are significantly anti-correlated with the radial velocity
residuals, and we use this correlation to reduce the residual rms to ~35m/s. We
find the star has a mass of either 1.38+-0.04 M_sun or 1.40+-0.10 M_sun, and a
radius of either 1.64+-0.03 R_sun or 1.78+-0.28 R_sun, while the planet has a
mass of either 0.762+-0.101 MJ or 0.763+-0.117 MJ, and a radius of either
1.686+-0.045 RJ or 1.827+-0.290 RJ, for an assumed circular orbit or for the
best-fit eccentric orbit respectively. Due to the large bisector span
variations exhibited by both stars we rely on detailed modeling of the
photometric light curves to rule out blend scenarios. Both planets are among
the largest radii transiting planets discovered to date.
06/2011;
-
John Asher Johnson,
J. N. Winn,
J. D. Hartman,
G. A. Bakos,
T. D. Morton, G. Torres,
Géza Kovács,
D. W. Latham,
R. W. Noyes,
B. Sato, [......],
A. W. Howard,
S. N. Quinn,
B. Beky,
D. D. Sasselov,
R. P. Stefanik,
J. Lazar,
I. Papp,
P. Sari,
L. A. Buchhave,
G. Furesz
[show abstract]
[hide abstract]
ABSTRACT: We report the discovery of HAT-P-30b, a transiting exoplanet orbiting the
V=10.419 dwarf star GSC 0208-00722. The planet has a period
P=2.810595+/-0.000005 d, transit epoch Tc = 2455456.46561+/-0.00037 (BJD), and
transit duration 0.0887+/-0.0015 d. The host star has a mass of 1.24+/-0.04
Msun, radius of 1.21+/-0.05 Rsun, effective temperature 6304+/-88 K, and
metallicity [Fe/H] = +0.13+/-0.08. The planetary companion has a mass of
0.711+/-0.028 Mjup, and radius of 1.340+/-0.065 Rjup yielding a mean density of
0.37+/-0.05 g cm^-3. We also present radial velocity measurements that were
obtained throughout a transit that exhibit the Rossiter-McLaughlin effect. By
modeling this effect we measure an angle of \lambda = 73.5+/-9.0 deg between
the sky projections of the planet's orbit normal and the star's spin axis.
HAT-P-30b represents another example of a close-in planet on a highly tilted
orbit, and conforms to the previously noted pattern that tilted orbits are more
common around stars with Teff > 6250 K.
03/2011;
-
L. A. Buchhave,
G. A. Bakos,
J. D. Hartman, G. Torres,
D. W. Latham,
J. Andersen,
G. Kovacs,
R. W. Noyes,
A. Shporer,
G. A. Esquerdo, [......],
D. D. Sasselov,
G. Furesz,
S. N. Quinn,
R. P. Stefanik,
T. Szklenar,
P. Berlind,
M. L. Calkins,
J. Lazar,
I. Papp,
P. Sari
[show abstract]
[hide abstract]
ABSTRACT: We present the discovery of two transiting exoplanets. HAT-P-28b orbits a
V=13.03 G3 dwarf star with a period P = 3.2572 d and has a mass of 0.63 +- 0.04
MJ and a radius of 1.21 + 0.11 -0.08 RJ yielding a mean density of 0.44 +- 0.09
g cm-3. HAT-P-29b orbits a V=11.90 F8 dwarf star with a period P = 5.7232 d and
has a mass of 0.78 +0.08 -0.04 MJ and a radius of 1.11 +0.14 -0.08 RJ yielding
a mean density of 0.71 +- 0.18 g cm-3. We discuss the properties of these
planets in the context of other known transiting planets.
03/2011;
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J. D. Hartman,
G. Á. Bakos,
D. M. Kipping, G. Torres,
G. Kovács,
R. W. Noyes,
D. W. Latham,
A. W. Howard,
D. A. Fischer,
J. A. Johnson, [......],
L. A. Buchhave,
B. Béky,
D. D. Sasselov,
R. P. Stefanik,
G. A. Esquerdo,
M. Everett,
G. Perumpilly,
J. Lázár,
I. Papp,
and P. Sári
[show abstract]
[hide abstract]
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 ± 0.03 M ☉, radius of 0.79+0.10 –0.04 R ☉, effective temperature 5079 ± 88 K, and metallicity [Fe/H] = -0.04 ± 0.08. The planetary companion has a mass of 0.059 ± 0.007 M J, and radius of 0.565+0.072 –0.032 R J yielding a mean density of 0.40 ± 0.10 g cm-3. 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 10 M ⊕ 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.
The Astrophysical Journal 01/2011; 728(2):138. · 6.02 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: We summarize the contribution of the HATNet project to extrasolar planet
science, highlighting published planets (HAT-P-1b through HAT-P-26b). We also
briefly discuss the operations, data analysis, candidate selection and
confirmation procedures, and we summarize what HATNet provides to the exoplanet
community with each discovery.
01/2011;
