130 research outputs found
Reporting the social indicators to the functional unit for food product. Theoretical contribution regarding the collection of relevant data
International audienceSeveral conceptions of social LCA lend on two often implicit hypothesis i)the source of impacts, the stressor would be either from technical origin, either from social one. It stems from it that relating the quantity of impacts to the quantity of functional unit has to be done through the unit processes, as it is done in ELCA. ii) companies are singly and freely choosing their practice, and even imposing social behaviour. We expect pointing out that we may build another representation. The values of the social indicators may be related proportionally to the functional units, if we handle them at the relevant level. Suggestions about the potential levels for picking up the data will conclude this proposal
Fruits and vegetables supply chains specificities and stakes as element of discussion on Social-LCA
International audienceAgri-food supply chains are at the heart of sustainable development concerns. In order to comprehend whole complex parameters and their global impacts, it appeared necessary to adopt a systemic approach, justifying a Life Cycle Assessment (LCA), not only from an environmental point of view but from a social and economic one too. Taking into account specificities and stakes of fruits and vegetables (F&V) supply chains in developing countries this paper focus on absences, deficiencies and methodological limits that LCA meets integrating social and economic aspects. The elements presented lead to an in-depth conceptual and theoretical discussion and suggest placing LCA in the perspective of development theory. The proposition is to endow LCA with an approach by capitals, which seems particularly adapted to express sustainable development and well-being
Transiting exoplanets from the CoRoT space mission III. The spectroscopic transit of CoRoT-Exo-2b with SOPHIE and HARPS
We report on the spectroscopic transit of the massive hot-Jupiter
CoRoT-Exo-2b observed with the high-precision spectrographs SOPHIE and HARPS.
By modeling the radial velocity anomaly occurring during the transit due to the
Rossiter-McLaughlin (RM) effect, we determine the sky-projected angle between
the stellar spin and the planetary orbital axis to be close to zero
lambda=7.2+-4.5 deg, and we secure the planetary nature of CoRoT-Exo-2b. We
discuss the influence of the stellar activity on the RM modeling. Spectral
analysis of the parent star from HARPS spectra are presented.Comment: A&A Letters (in press), 5 pages, 2 figure
Characterization of the HD 17156 planetary system
AIMS : To improve the parameters of the HD 17156 system (peculiar due to the
eccentric and long orbital period of its transiting planet) and constrain the
presence of stellar companions.
METHODS : Photometric data were acquired for 4 transits, and high precision
radial velocity measurements were simultaneously acquired with SARG@TNG for one
transit. The template spectra of HD 17156 was used to derive effective
temperature, gravity, and metallicity. A fit of the photometric and
spectroscopic data was performed to measure the stellar and planetary radii,
and the spin-orbit alignment. Planet orbital elements and ephemeris were
derived from the fit. Near infrared adaptive optic images was acquired with
ADOPT@TNG.
RESULTS: We have found that the star has a radius of R_S = 1.43+/-0.03 R_sun
and the planet R_P =1.02+/-0.08 R_jup. The transit ephemeris is T_c =
2454\756.73134+/-0.00020+N*21.21663+/-0.00045 BJD. The analysis of the
Rossiter-Mclaughlin effect shows that the system is spin orbit aligned with an
angle lambda = 4.8 +/- 5.3 deg. The analysis of high resolution images has not
revealed any stellar companion with projected separation between 150 and 1000
AU from HD 17156.Comment: submitted to A&
The SOPHIE search for northern extrasolar planets. II. A multi-planet system around HD9446
We report the discovery of a planetary system around HD9446, performed from
radial velocity measurements secured with the spectrograph SOPHIE at the 193-cm
telescope of the Haute-Provence Observatory during more than two years. At
least two planets orbit this G5V, active star: HD9446b has a minimum mass of
0.7 M_Jup and a slightly eccentric orbit with a period of 30 days, whereas
HD9446c has a minimum mass of 1.8 M_Jup and a circular orbit with a period of
193 days. As for most of the known multi-planet systems, the HD9446-system
presents a hierarchical disposition, with a massive outer planet and a lighter
inner planet.Comment: 7 pages, 6 figures, 3 tables, accepted for publication in A&
Stellar activity of planetary host star HD 189733
Extra-solar planet search programs require high-precision velocity
measurements. They need to study how to disentangle radial-velocity variations
due to Doppler motion from the noise induced by stellar activity. We monitored
the active K2V star HD 189733 and its transiting planetary companion that has a
2.2-day orbital period. We used the high-resolution spectograph SOPHIE mounted
on the 1.93-m telescope at the Observatoire de Haute-Provence to obtain 55
spectra of HD 189733 over nearly two months. We refined the HD 189733b orbit
parameters and put limits on the eccentricity and on a long-term velocity
gradient. After subtracting the orbital motion of the planet, we compared the
variability of spectroscopic activity indices to the evolution of the
radial-velocity residuals and the shape of spectral lines. The radial velocity,
the spectral-line profile and the activity indices measured in HeI (5875.62
\AA), Halpha (6562.81 \AA) and the CaII H&K lines (3968.47 \AA and 3933.66 \AA,
respectively) show a periodicity around the stellar rotation period and the
correlations between them are consistent with a spotted stellar surface in
rotation. We used such correlations to correct for the radial-velocity jitter
due to stellar activity. This results in achieving high precision on the orbit
parameters, with a semi-amplitude K = 200.56 \pm 0.88 m.s-1 and a derived
planet mass of M_{P}=1.13 \pm 0.03 M.Comment: 9 pages, 2 tables, 9 figures, accepted for publication in A&A on
20/11/200
The 0.5MJ transiting exoplanet WASP-13b
We report the discovery of WASP-13b, a low-mass M_{\rm p} = 0.46 ^_~M_J transiting exoplanet with an orbital period of 4.35298 0.00004 days. The transit has a depth of 9 mmag, and although our follow-up photometry does not allow us to constrain the impact parameter well (0 < b < 0.46), with radius in the range ~ 1.06-1.21 RJ the location of WASP-13b in the mass-radius plane is nevertheless consistent with H/He-dominated, irradiated, low core mass and core-free theoretical models. The G1V host star is similar to the Sun in mass (M__ ~M_{\odot}) and metallicity ([M/H] = 0.00.2), but is possibly older ( 8.5^_{\rm -4.9} Gyr)
Extrasolar planets and brown dwarfs around A-F type stars - VII. Theta Cygni radial velocity variations: planets or stellar phenomenon?
(abridged) In the frame of the search for extrasolar planets and brown dwarfs
around early-type main-sequence stars, we present the results obtained on the
early F-type star Theta Cygni. Elodie and Sophie at OHP were used to obtain the
spectra. Our dedicated radial-velocity measurement method was used to monitor
the star's radial velocities over five years. We also use complementary, high
angular resolution and high-contrast images taken with PUEO at CFHT. We show
that Theta Cygni radial velocities are quasi-periodically variable, with a
~150-day period. These variations are not due to the ~0.35-Msun stellar
companion that we detected in imaging at more than 46 AU from the star. The
absence of correlation between the bisector velocity span variations and the
radial velocity variations for this 7 km/s vsini star, as well as other
criteria indicate that the observed radial velocity variations are not due to
stellar spots. The observed amplitude of the bisector velocity span variations
also seems to rule out stellar pulsations. However, we observe a peak in the
bisector velocity span periodogram at the same period as the one found in the
radial velocity periodogram, which indicates a probable link between these
radial velocity variations and the low amplitude lineshape variations which are
of stellar origin. Long-period variations are not expected from this type of
star to our knowledge. If a stellar origin (hence of new type) was to be
confirmed for these long-period radial velocity variations, this would have
several consequences on the search for planets around main-sequence stars, both
in terms of observational strategy and data analysis. An alternative
explanation for these variable radial velocities is the presence of at least
one planet of a few Jupiter masses orbiting at less than 1 AU. (abridged)Comment: 9 pages, accepted in A
Elodie metallicity-biased search for transiting Hot Jupiters IV. Intermediate period planets orbiting the stars HD43691 and HD132406
We report here the discovery of two planet candidates as a result of our
planet-search programme biased in favour of high-metallicity stars, using the
ELODIE spectrograph at the Observatoire de Haute Provence. One of them has a
minimum mass m_2\sin{i} = 2.5 M_Jup and is orbiting the metal-rich star HD43691
with period P = 40 days and eccentricity e = 0.14. The other planet has a
minimum mass m_2\sin{i} = 5.6 M_Jup and orbits the slightly metal-rich star
HD132406 with period P = 974 days and eccentricity e = 0.34. Both stars were
followed up with additional observations using the new SOPHIE spectrograph that
replaces the ELODIE instrument, allowing an improved orbital solution for the
systems.Comment: 6 pages, 4 figures, to be published in A&
Refined parameters and spectroscopic transit of the super-massive planet HD147506b
In this paper, we report a refined determination of the orbital parameters
and the detection of the Rossiter-McLaughlin effect of the recently discovered
transiting exoplanet HD147506b (HAT-P-2b). The large orbital eccentricity at
the short orbital period of this exoplanet is unexpected and is distinguishing
from other known transiting exoplanets. We performed high-precision radial
velocity spectroscopic observations of HD147506 (HAT-P-2) with the new
spectrograph SOPHIE, mounted on the 1.93 m telescope at the Haute-Provence
observatory (OHP). We obtained 63 new measurements, including 35 on May 14 and
20 on June 11, when the planet was transiting its parent star. The radial
velocity (RV) anomaly observed illustrates that HAT-P-2b orbital motion is set
in the same direction as its parent star spin. The sky-projected angle between
the normal of the orbital plane and the stellar spin axis, \lambda = 0.2 +12.2
-12.5 deg, is consistent with zero. The planetary and stellar radii were
re-determined, yielding R_p = 0.951 +0.039 -0.053 R_Jup, R_s = 1.416 +0.040
-0.062 R_Sun. The mass M_p = 8.62 +0.39 -0.55 M_Jup and radius of HAT-P-2b
indicate a density of 12.5 +2.6 -3.6 g cm^{-3}, suggesting an object in between
the known close-in planets with typical density of the order of 1 g cm^{-3},
and the very low-mass stars, with density greater than 50 g cm^{-3}.Comment: Submitted to A&A; V2: Replaced by accepted versio
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