D. Segransan
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
D. Segransan has a total of 192 co-authors. Here are the top co-authors by number of shared publications:
S. Udry
Observatoire astronomique de l'Université de Genève, 51 ch. des Maillettes, CH-1290 Sauverny, Switzerland
18 shared publicationsF. Pepe
Observatoire astronomique de l'Université de Genève, 51 ch. des Maillettes, CH-1290 Sauverny, Switzerland
13 shared publications- Michael Gillon
University of Liège
11 shared publications - Andrew Collier Cameron
Centre for Exoplanet Science, SUPA School of Physics and Astronomy, University of St Andrews
9 shared publications - Coel Hellier
Astrophysics Group, Keele University, Staffordshire ST5 5BG, UK
9 shared publications - D. Pollacco
Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, University Road, Belfast BT7 1NN, UK
9 shared publications
Latest Publications
- 2 November 2015
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 455 (1) , 357-369
Parallax of the L4.5 dwarf 2M1821+14 from high-precision astrometry with OSIRIS at GTC
We used the OSIRIS camera at the 10.4 m Gran Telescopio Canarias (GTC) to monitor the astrometric motion of the L4.5 dwarf 2M1821+14 over 17 months. The astrometric residuals of 11 epochs have an rms dispersion of 0.4 mas, which is larger than the average precision of 0.23 mas per epoch and hints towards an additional signal or excess noise. Comparison of the point-spread functions in OSIRIS and FORS2/VLT images reveals no differences critical for high-precision astrometry, despite the GTC's segmented primary mirror. We attribute the excess noise to an unknown effect that may be uncovered with additional data. For 2M1821+14, we measured a relative parallax of 106.15 ± 0.18 mas and determined a correction of 0.50 ± 0.05 mas to absolute parallax, leading to a distance of 9.38 ± 0.03 pc. We excluded at 3σ confidence the presence of a companion to 2M1821+14 down to a mass ratio of 0.1 (≈5 MJupiter) with a period of 50–1000 d and a separation of 0.1–0.7 au. The accurate parallax allowed us to estimate the age and mass of 2M1821+14 of 120–700 Myr and 0.049$$^{+0.014}_{-0.024}$$ M⊙, thus confirming its intermediate age and substellar mass. We complement our study with a parallax and proper motion catalogue of 587 stars (i′ ≃ 15.5–22) close to 2M1821+14, used as astrometric references. This study demonstrates submas astrometry with the GTC, a capability applicable for a variety of science cases including the search for extrasolar planets and relevant for future astrometric observations with E-ELT and TMT.- 2 November 2015
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 455 (1) , 357-369
Parallax of the L4.5 dwarf 2M1821+14 from high-precision astrometry with OSIRIS at GTC
We used the OSIRIS camera at the 10.4 m Gran Telescopio Canarias (GTC) to monitor the astrometric motion of the L4.5 dwarf 2M1821+14 over 17 months. The astrometric residuals of 11 epochs have an rms dispersion of 0.4 mas, which is larger than the average precision of 0.23 mas per epoch and hints towards an additional signal or excess noise. Comparison of the point-spread functions in OSIRIS and FORS2/VLT images reveals no differences critical for high-precision astrometry, despite the GTC's segmented primary mirror. We attribute the excess noise to an unknown effect that may be uncovered with additional data. For 2M1821+14, we measured a relative parallax of 106.15 ± 0.18 mas and determined a correction of 0.50 ± 0.05 mas to absolute parallax, leading to a distance of 9.38 ± 0.03 pc. We excluded at 3σ confidence the presence of a companion to 2M1821+14 down to a mass ratio of 0.1 (≈5 MJupiter) with a period of 50–1000 d and a separation of 0.1–0.7 au. The accurate parallax allowed us to estimate the age and mass of 2M1821+14 of 120–700 Myr and 0.049$$^{+0.014}_{-0.024}$$ M⊙, thus confirming its intermediate age and substellar mass. We complement our study with a parallax and proper motion catalogue of 587 stars (i′ ≃ 15.5–22) close to 2M1821+14, used as astrometric references. This study demonstrates submas astrometry with the GTC, a capability applicable for a variety of science cases including the search for extrasolar planets and relevant for future astrometric observations with E-ELT and TMT.- Open Access
- 17 April 2014
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 440 (4) , 3392-3401
A window on exoplanet dynamical histories: Rossiter–McLaughlin observations of WASP-13b and WASP-32b
We present Rossiter–McLaughlin observations of WASP-13b and WASP-32b and determine the sky-projected angle between the normal of the planetary orbit and the stellar rotation axis (λ). WASP-13b and WASP-32b both have prograde orbits and are consistent with alignment with measured sky-projected angles of $$\lambda =8{^{\circ }}^{+13}_{-12}$$ and $$\lambda =-2{^{\circ }}^{+17}_{-19}$$, respectively. Both WASP-13 and WASP-32 have Teff < 6250 K, and therefore, these systems support the general trend that aligned planetary systems are preferentially found orbiting cool host stars. A Lomb–Scargle periodogram analysis was carried out on archival SuperWASP data for both systems. A statistically significant stellar rotation period detection (above 99.9 per cent confidence) was identified for the WASP-32 system with Prot = 11.6 ± 1.0 days. This rotation period is in agreement with the predicted stellar rotation period calculated from the stellar radius, R*, and vsin i if a stellar inclination of i* = 90° is assumed. With the determined rotation period, the true 3D angle between the stellar rotation axis and the planetary orbit, ψ, was found to be ψ = 11° ± 14°. We conclude with a discussion on the alignment of systems around cool host stars with Teff < 6150 K by calculating the tidal dissipation time-scale. We find that systems with short tidal dissipation time-scales are preferentially aligned and systems with long tidal dissipation time-scales have a broad range of obliquities.- 17 April 2014
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 440 (4) , 3392-3401
Open AccessA window on exoplanet dynamical histories: Rossiter–McLaughlin observations of WASP-13b and WASP-32b
We present Rossiter–McLaughlin observations of WASP-13b and WASP-32b and determine the sky-projected angle between the normal of the planetary orbit and the stellar rotation axis (λ). WASP-13b and WASP-32b both have prograde orbits and are consistent with alignment with measured sky-projected angles of $$\lambda =8{^{\circ }}^{+13}_{-12}$$ and $$\lambda =-2{^{\circ }}^{+17}_{-19}$$, respectively. Both WASP-13 and WASP-32 have Teff < 6250 K, and therefore, these systems support the general trend that aligned planetary systems are preferentially found orbiting cool host stars. A Lomb–Scargle periodogram analysis was carried out on archival SuperWASP data for both systems. A statistically significant stellar rotation period detection (above 99.9 per cent confidence) was identified for the WASP-32 system with Prot = 11.6 ± 1.0 days. This rotation period is in agreement with the predicted stellar rotation period calculated from the stellar radius, R*, and vsin i if a stellar inclination of i* = 90° is assumed. With the determined rotation period, the true 3D angle between the stellar rotation axis and the planetary orbit, ψ, was found to be ψ = 11° ± 14°. We conclude with a discussion on the alignment of systems around cool host stars with Teff < 6150 K by calculating the tidal dissipation time-scale. We find that systems with short tidal dissipation time-scales are preferentially aligned and systems with long tidal dissipation time-scales have a broad range of obliquities. - 8 April 2014
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 786 (1)
TRANSIT CONFIRMATION AND IMPROVED STELLAR AND PLANET PARAMETERS FOR THE SUPER-EARTH HD 97658 b AND ITS HOST STAR
- 8 April 2014
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 786 (1)
TRANSIT CONFIRMATION AND IMPROVED STELLAR AND PLANET PARAMETERS FOR THE SUPER-EARTH HD 97658 b AND ITS HOST STAR
- 25 March 2014
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 563, A143
Transiting planets from WASP-South, Euler, and TRAPPIST
Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics
- 25 March 2014
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 563, A143
Transiting planets from WASP-South, Euler, and TRAPPIST
Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics
- Open Access
- 25 April 2013
- Published by EDP Sciences in EPJ Web of Conferences
- Vol. 47, 05004
Prized results from HARPS
EPJ Web of Conferences, open-access proceedings in physics and related sciences
- 25 April 2013
- Published by EDP Sciences in EPJ Web of Conferences
- Vol. 47, 05004
Open AccessPrized results from HARPS
EPJ Web of Conferences, open-access proceedings in physics and related sciences
- 11 April 2013
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 552
WASP-71b: a bloated hot Jupiter in a 2.9-day, prograde orbit around an evolved F8 star
- 11 April 2013
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 552
WASP-71b: a bloated hot Jupiter in a 2.9-day, prograde orbit around an evolved F8 star
- 1 January 2013
- Published by IOP Publishing in Publications of the Astronomical Society of the Pacific
- Vol. 125 (923) , 48-55
WASP-77 Ab: A Transiting Hot Jupiter Planet in a Wide Binary System1
We report the discovery of a transiting planet with an orbital period of 1.36 days orbiting the brighter component of the visual binary star BD 07 436. The host star, WASP-77 A, is a moderately bright G8 V star (V=10.3) with a metallicity close to solar ([Fe/H] = 0.0 ± 0.1). The companion star, WASP-77 B, is a K-dwarf approximately 2 mag fainter at a separation of approximately 3″. The spectrum of WASP-77 A shows emission in the cores of the Caii H and K lines, indicative of moderate chromospheric activity. The Wide Angle Search for Planets (WASP) light curves show photometric variability with a period of 15.3 days and an amplitude of about 0.3% that is probably due to the magnetic activity of the host star. We use an analysis of the combined photometric and spectroscopic data to derive the mass and radius of the planet (1.76 ± 0.06 MJup, 1.21 ± 0.02 RJup). The age of WASP-77 A estimated from its rotation rate (˜1 Gyr) agrees with the age estimated in a similar way for WASP-77 B (˜0.6 Gyr) but is in poor agreement with the age inferred by comparing its effective temperature and density to stellar models (˜8 Gyr). Follow-up observations of WASP-77 Ab will make a useful contribution to our understanding of the influence of binarity and host star activity on the properties of hot Jupiters.Publisher PDFPeer reviewe
- 1 January 2013
- Published by IOP Publishing in Publications of the Astronomical Society of the Pacific
- Vol. 125 (923) , 48-55
WASP-77 Ab: A Transiting Hot Jupiter Planet in a Wide Binary System1
We report the discovery of a transiting planet with an orbital period of 1.36 days orbiting the brighter component of the visual binary star BD 07 436. The host star, WASP-77 A, is a moderately bright G8 V star (V=10.3) with a metallicity close to solar ([Fe/H] = 0.0 ± 0.1). The companion star, WASP-77 B, is a K-dwarf approximately 2 mag fainter at a separation of approximately 3″. The spectrum of WASP-77 A shows emission in the cores of the Caii H and K lines, indicative of moderate chromospheric activity. The Wide Angle Search for Planets (WASP) light curves show photometric variability with a period of 15.3 days and an amplitude of about 0.3% that is probably due to the magnetic activity of the host star. We use an analysis of the combined photometric and spectroscopic data to derive the mass and radius of the planet (1.76 ± 0.06 MJup, 1.21 ± 0.02 RJup). The age of WASP-77 A estimated from its rotation rate (˜1 Gyr) agrees with the age estimated in a similar way for WASP-77 B (˜0.6 Gyr) but is in poor agreement with the age inferred by comparing its effective temperature and density to stellar models (˜8 Gyr). Follow-up observations of WASP-77 Ab will make a useful contribution to our understanding of the influence of binarity and host star activity on the properties of hot Jupiters.Publisher PDFPeer reviewe
- Open Access
- 23 April 2012
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 422 (3) , 1988-1998
WASP-44b, WASP-45b and WASP-46b: three short-period, transiting extrasolar planets
- 23 April 2012
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 422 (3) , 1988-1998
Open AccessWASP-44b, WASP-45b and WASP-46b: three short-period, transiting extrasolar planets
- 16 August 2011
- Published by American Astronomical Society in The Astronomical Journal
- Vol. 142 (3) , 86
WASP-35b, WASP-48b, AND HAT-P-30b/WASP-51b: TWO NEW PLANETS AND AN INDEPENDENT DISCOVERY OF A HAT PLANET
We report the detection of WASP-35b, a planet transiting a metal-poor ([Fe/H] = –0.15) star in the Southern hemisphere, WASP-48b, an inflated planet which may have spun-up its slightly evolved host star of 1.75 R ☉ in the Northern hemisphere, and the independent discovery of HAT-P-30b/WASP-51b, a new planet in the Northern hemisphere. Using WASP, RISE, Faulkes Telescope South, and TRAPPIST photometry, with CORALIE, SOPHIE, and NOT spectroscopy, we determine that WASP-35b has a mass of 0.72 ± 0.06 MJ and radius of 1.32 ± 0.05RJ , and orbits with a period of 3.16 days, WASP-48b has a mass of 0.98 ± 0.09 MJ , radius of 1.67 ± 0.10 RJ , and orbits in 2.14 days, while HAT-P-30b/WASP-51b, with an orbital period of 2.81 days, is found to have a mass of 0.76 ± 0.05 MJ and radius of 1.42 ± 0.03 RJ , agreeing with values of 0.71 ± 0.03 MJ and 1.34 ± 0.07 RJ reported for HAT-P-30b.
- 16 August 2011
- Published by American Astronomical Society in The Astronomical Journal
- Vol. 142 (3) , 86
WASP-35b, WASP-48b, AND HAT-P-30b/WASP-51b: TWO NEW PLANETS AND AN INDEPENDENT DISCOVERY OF A HAT PLANET
We report the detection of WASP-35b, a planet transiting a metal-poor ([Fe/H] = –0.15) star in the Southern hemisphere, WASP-48b, an inflated planet which may have spun-up its slightly evolved host star of 1.75 R ☉ in the Northern hemisphere, and the independent discovery of HAT-P-30b/WASP-51b, a new planet in the Northern hemisphere. Using WASP, RISE, Faulkes Telescope South, and TRAPPIST photometry, with CORALIE, SOPHIE, and NOT spectroscopy, we determine that WASP-35b has a mass of 0.72 ± 0.06 MJ and radius of 1.32 ± 0.05RJ , and orbits with a period of 3.16 days, WASP-48b has a mass of 0.98 ± 0.09 MJ , radius of 1.67 ± 0.10 RJ , and orbits in 2.14 days, while HAT-P-30b/WASP-51b, with an orbital period of 2.81 days, is found to have a mass of 0.76 ± 0.05 MJ and radius of 1.42 ± 0.03 RJ , agreeing with values of 0.71 ± 0.03 MJ and 1.34 ± 0.07 RJ reported for HAT-P-30b.
- Open Access
- 25 February 2011
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 528, L8
HD 5388 b is a 69 MJupcompanion instead of a planet
- 25 February 2011
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 528, L8
Open AccessHD 5388 b is a 69 MJupcompanion instead of a planet