1. |
- Gould, A., et al.
(author)
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MOA-2010-BLG-523:" Failed Planet"= RS CVn Star
- 2013
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In: Astrophysical Journal. - 0004-637X. ; 763:2
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Journal article (peer-reviewed)abstract
- The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing light curve near the peak of an A(max) similar to 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for a planetary companion to the principal lens. We combine long-term photometric monitoring with a previously published high-resolution spectrum taken near peak to demonstrate that this is an RS CVn variable, so that planetary microlensing is not required to explain the light-curve deviations. This is the first spectroscopically confirmed RS CVn star discovered in the Galactic bulge.
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2. |
- Simpson, E. K., et al.
(author)
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WASP-37b : A 1.8 MJ exoplanet transiting a metal-poor star
- 2011
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In: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 141:1, s. 8-
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Journal article (peer-reviewed)abstract
- We report on the discovery of WASP-37b, a transiting hot Jupiter orbiting an m(v) = 12.7 G2-type dwarf, with a period of 3.577469 +/- 0.000011 d, transit epoch T-0 = 2455338.6188 +/- 0.0006 (HJD; dates throughout the paper are given in Coordinated Universal Time (UTC)), and a transit duration 0.1304(-0.0017)(+0.0018) d. The planetary companion has a mass M-p = 1.80 +/- 0.17 M-J and radius R-p = 1.16(-0.06)(+0.07) R-J, yielding a mean density of 1.15(-0.15)(+0.12) rho(J). From a spectral analysis, we find that the host star has M-star = 0.925 +/- 0.120 M-circle dot, R-star = 1.003 +/- 0.053 R-circle dot, T-eff = 5800 +/- 150 K, and [Fe/H] = -0.40 +/- 0.12. WASP-37 is therefore one of the lowest metallicity stars to host a transiting planet.
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3. |
- Simpson, E. K., et al.
(author)
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Independent Discovery of the Transiting Exoplanet HAT-P-14b
- 2011
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In: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 141:5, s. 161-
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Journal article (peer-reviewed)abstract
- We present SuperWASP observations of HAT-P-14b, a hot Jupiter discovered by Torres et al. The planet was found independently by the SuperWASP team and named WASP-27b after follow-up observations had secured the discovery, but prior to the publication by Torres et al. Our analysis of HAT-P-14/WASP-27 is in good agreement with the values found by Torres et al. and we provide additional evidence against astronomical false positives. Due to the brightness of the host star, V-mag = 10, HAT-P-14b is an attractive candidate for further characterization observations. The planet has a high impact parameter and the primary transit is close to grazing. This could readily reveal small deviations in the orbital parameters indicating the presence of a third body in the system, which may be causing the small but significant orbital eccentricity. Our results suggest that the planet may undergo a grazing secondary eclipse. However, even a non-detection would tightly constrain the system parameters.
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4. |
- Bouchy, F., et al.
(author)
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WASP-21b : a hot-Saturn exoplanet transiting a thick disc star
- 2010
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 519, s. A98-
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Journal article (peer-reviewed)abstract
- We report the discovery of WASP-21b, a new transiting exoplanet discovered by the Wide Angle Search for Planets ( WASP) Consortium and established and characterized with the FIES, SOPHIE, CORALIE and HARPS fiber-fed echelle spectrographs. A 4.3-d period, 1.1% transit depth and 3.4-h duration are derived for WASP-21b using SuperWASP-North and high precision photometric observations at the Liverpool Telescope. Simultaneous fitting to the photometric and radial velocity data with a Markov Chain Monte Carlo procedure leads to a planet in the mass regime of Saturn. With a radius of 1.07 R-Jup and mass of 0.30 M-Jup, WASP-21b has a density close to 0.24 rho(Jup) corresponding to the distribution peak at low density of transiting gaseous giant planets. With a host star metallicity [Fe/H] of -0.46, WASP-21b strengthens the correlation between planetary density and host star metallicity for the five known Saturn-like transiting planets. Furthermore there are clear indications that WASP-21b is the first transiting planet belonging to the thick disc.
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5. |
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6. |
- Street, R. A., et al.
(author)
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WASP-24 B : A new transiting close-in hot jupiter orbiting a late F-star
- 2010
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In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 720:1, s. 337-343
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Journal article (peer-reviewed)abstract
- We report the discovery of a new transiting close-in giant planet, WASP-24 b, in a 2.341 day orbit, 0.037 AU from its F8-9 type host star. By matching the star's spectrum with theoretical models, we infer an effective temperature T-eff = 6075 +/- 100 K and a surface gravity of log g = 4.15 +/- 0.10. A comparison of these parameters with theoretical isochrones and evolutionary mass tracks places only weak constraints on the age of the host star, which we estimate to be 3.8(-1.2)(+1.3) Gyr. The planetary nature of the companion was confirmed by radial velocity measurements and additional photometric observations. These data were fit simultaneously in order to determine the most probable parameter set for the system, from which we infer a planetary mass of 1.071(-0.038)(+0.036) M-Jup and radius 1.3(-0.037)(+0.039) R-Jup.
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7. |
- Fossati, L., et al.
(author)
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Metals in the exosphere of the highly irradiated planet WASP-12b
- 2010
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In: Astrophysical Journal Letters. - 2041-8205. ; 714:2, s. L222-L227
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Journal article (peer-reviewed)abstract
- We present near-UV transmission spectroscopy of the highly irradiated transiting exoplanet WASP-12b, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. The spectra cover three distinct wavelength ranges: NUVA (2539-2580 angstrom), NUVB (2655-2696 angstrom), and NUVC (2770-2811 angstrom). Three independent methods all reveal enhanced transit depths attributable to absorption by resonance lines of metals in the exosphere of WASP-12b. Light curves of total counts in the NUVA and NUVC wavelength ranges show a detection at a 2.5 sigma level. We detect extra absorption in the Mg II lambda lambda 2800 resonance line cores at the 2.8 sigma level. The NUVA, NUVB, and NUVC light curves imply effective radii of 2.69 +/- 0.24 R-J, 2.18 +/- 0.18 R-J, and 2.66 +/- 0.22 R-J respectively, suggesting the planet is surrounded by an absorbing cloud which overfills the Roche lobe. We detect enhanced transit depths at the wavelengths of resonance lines of neutral sodium, tin, and manganese, and at singly ionized ytterbium, scandium, manganese, aluminum, vanadium, and magnesium. We also find the statistically expected number of anomalous transit depths at wavelengths not associated with any known resonance line. Our data are limited by photon noise, but taken as a whole the results are strong evidence for an extended absorbing exosphere surrounding the planet. The NUVA data exhibit an early ingress, contrary to model expectations; we speculate this could be due to the presence of a disk of previously stripped material.
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8. |
- Hebb, L., et al.
(author)
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MML 53 : a new low-mass, pre-main sequence eclipsing binary in the Upper Centaurus-Lupus region discovered by SuperWASP
- 2010
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 522:2, s. A37-
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Journal article (peer-reviewed)abstract
- We announce the discovery of a new low-mass, pre-main sequence eclipsing binary, MML 53. Previous observations of MML 53 found it to be a pre-main sequence spectroscopic multiple associated with the 15-22 Myr Upper Centaurus-Lupus cluster. We identify the object as an eclipsing binary for the first time through the analysis of multiple seasons of time series photometry from the SuperWASP transiting planet survey. Re-analysis of a single archive spectrum shows MML 53 to be a spatially unresolved triple system of young stars which all exhibit significant lithium absorption. Two of the components comprise an eclipsing binary with period, P = 2.097891(6) +/- 0.000005 and mass ratio, q similar to 0.8. Here, we present the analysis of the discovery data.
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9. |
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10. |
- Nystedt, Björn, et al.
(author)
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The Norway spruce genome sequence and conifer genome evolution
- 2013
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In: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 497:7451, s. 579-584
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Journal article (peer-reviewed)abstract
- Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinus sylvestris, Abies sibirica, Juniperus communis, Taxus baccata and Gnetum gnemon reveals that the transposable element diversity is shared among extant conifers. Expression of 24-nucleotide small RNAs, previously implicated in transposable element silencing, is tissue-specific and much lower than in other plants. We further identify numerous long (>10,000 base pairs) introns, gene-like fragments, uncharacterized long non-coding RNAs and short RNAs. This opens up new genomic avenues for conifer forestry and breeding.
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