GRACES: Gemini remote access to CFHT ESPaDOnS spectrograph through the longest astronomical fiber ever made: experimental phase completed

Chené, André-Nicolas; Pazder, John; Barrick, Gregory; Anthony, André; Benedict, Tom; Duncan, David L.; Gigoux, Pedro; Kleinman, S. J.; Malo, Lison; Martioli, Eder; Moutou, C.; Placco, Vinicius M.; Reshetovand, Vladimir; Rhee, Jaehyon; Roth, Katherine C.; Schiavon, Ricardo P.; Tollestrup, E. V.; Vermeulen, Tom; White, J.K.; Wooff, Robert

doi:10.1117/12.2057417

Cited by 34 publications

(14 citation statements)

References 10 publications

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“…Currently, we are running a Gemini/GRACES Large and Long Program to follow-up with high SNR (> 100) spectra for our best metal-poor candidates ([Fe/H] < −3.5) and with V < 17 selected from medium resolution spectroscopy. We also plan to observe a selection of these stars with the upcoming Gemini GHOST spectrograph (Chene et al 2014;Sheinis et al 2017), which is anticipated to have excellent throughput at blue-UV wavelengths, providing far more iron-group lines for stellar parameter assessments and many more spectral lines of heavy neutron-capture (and light) elements.…”

Section: Discussionmentioning

confidence: 99%

The Pristine survey – IX. CFHT ESPaDOnS spectroscopic analysis of 115 bright metal-poor candidate stars

Venn

Kielty

Sestito

et al. 2019

Monthly Notices of the Royal Astronomical Society

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A chemo-dynamical analysis of 115 metal-poor candidate stars selected from the narrow-band Pristine photometric survey is presented based on CFHT highresolution ESPaDOnS spectroscopy. We have discover 28 new bright (V < 15) stars with [Fe/H]< −2.5 and 5 with [Fe/H]< −3.0 for success rates of 40% (28/70) and 19% (5/27), respectively. A detailed model atmospheres analysis is carried out for the 28 new metal-poor stars. Stellar parameters were determined from SDSS photometric colours, Gaia DR2 parallaxes, MESA/MIST stellar isochrones, and the initial Pristine survey metallicities, following a Bayesian inference method. Chemical abundances are determined for 10 elements (Na, Mg, Ca, Sc, Ti, Cr, Fe, Ni, Y, Ba). Most stars show chemical abundance patterns that are similar to the normal metal-poor stars in the Galactic halo; however, we also report the discoveries of a new r-process rich star, a new CEMP-s candidate with [Y/Ba]>0, and a metal-poor star with very low [Mg/Fe]. The kinematics and orbits for all of the highly probable metal-poor candidates are determined by combining our precision radial velocities with Gaia DR2 proper motions. Some stars show unusual kinematics for their chemistries, including planar orbits, unbound orbits, and highly elliptical orbits that plunge deeply into the Galactic bulge (R peri < 0.5 kpc); also, eight stars have orbital energies and actions consistent with the Gaia-Enceladus accretion event. This paper contributes to our understanding of the complex chemo-dynamics of the metal-poor Galaxy, and increases the number of known bright metal-poor stars available for detailed nucleosynthetic studies.

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Section: Discussionmentioning

confidence: 99%

The Pristine survey – IX. CFHT ESPaDOnS spectroscopic analysis of 115 bright metal-poor candidate stars

Venn

Kielty

Sestito

et al. 2019

Monthly Notices of the Royal Astronomical Society

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“…The sample consists of three solar twins observed with the Gemini Remote Access to CFHT ESPaDOns Spectrograph 1 (GRACES, Chene et al 2014) at the Gemini North Observatory with high resolution (R∼45000) and moderately high S/N (S/N∼100) on the night of 2016 December 23, 24, 25, and 27 (observation program GN-2016B-Q-36). The sample, presented in Table 1, was chosen from a list built with M67 objects that have high membership probabilities, calculated using proper motion from Yadav et al (2008), previous spectroscopic studies by Pasquini et al (2008), and further studies of radial velocity by Geller et al (2015).…”

Section: Sample and Analysismentioning

confidence: 99%

Li abundances for solar twins in the open cluster M67

Carlos

Meléndez

Nascimento

et al. 2019

Monthly Notices of the Royal Astronomical Society

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We determine lithium (Li) abundances for solar twins in the M67 open cluster to add valuable information about the correlation between Li depletion and stellar age and, then, better understand stellar structure and evolution. We use high resolution and good signal-to-noise ratio spectra to characterize Li depletion in three solar twins from M67, using spectral synthesis in the region of the asymmetric 6707.75Å Li I feature. The mean Li abundance value of A(Li)= 1.6 ± 0.2 dex for our sample of M67 solar twins (our three stars plus a fourth solar twin from a previous analysis in the literature) presents Li abundance expected for its age. Also, the scatter estimated from the standard deviation of the Li abundances in this work is similar to the typical scatter found in a sample of field solar twins presented in the literature.

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“…Following our intensive campaign in late 2015 (D16), V830 Tau was re-observed from 2016 Jan 14 to Feb 10, using again ES-PaDOnS at the CFHT, its clone Narval at the TBL, and ES-PaDOnS coupled to Gemini-North through the GRACES fiber link (Chene et al 2014). ESPaDOnS and Narval collect spectra covering 370 to 1,000 nm at a resolving power of 65,000 (Donati 2003).…”

Section: Spectropolarimetric and Photometric Observations Of V830 Taumentioning

confidence: 99%

The hot Jupiter of the magnetically active weak-line T Tauri star V830 Tau

Donati¹,

Yu²,

Moutou³

et al. 2016

Mon. Not. R. Astron. Soc.

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We report results of an extended spectropolarimetric and photometric monitoring of the weakline T Tauri star V830 Tau and its recently-detected newborn close-in giant planet. Our observations, carried out within the MaTYSSE programme, were spread over 91 d, and involved the ESPaDOnS and Narval spectropolarimeters linked to the 3.6-m Canada-France-Hawaii, the 2m Bernard Lyot and the 8-m Gemini-North Telescopes. Using Zeeman-Doppler Imaging, we characterize the surface brightness distributions, magnetic topologies and surface differential rotation of V830 Tau at the time of our observations, and demonstrate that both distributions evolve with time beyond what is expected from differential rotation. We also report that near the end of our observations, V830 Tau triggered one major flare and two weaker precursors, showing up as enhanced red-shifted emission in multiple spectral activity proxies.With 3 different filtering techniques, we model the radial velocity (RV) activity jitter (of semi-amplitude 1.2 km s −1 ) that V830 Tau generates, successfully retrieve the 68 ± 11 m s −1 RV planet signal hiding behind the jitter, further confirm the existence of V830 Tau b and better characterize its orbital parameters. We find that the method based on Gaussian-process regression performs best thanks to its higher ability at modelling not only the activity jitter, but also its temporal evolution over the course of our observations, and succeeds at reproducing our RV data down to a rms precision of 35 m s −1 . Our result provides new observational constraints on scenarios of star / planet formation and demonstrates the scientific potential of large-scale searches for close-in giant planets around T Tauri stars.

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GRACES: Gemini remote access to CFHT ESPaDOnS spectrograph through the longest astronomical fiber ever made: experimental phase completed

Cited by 34 publications

References 10 publications

The Pristine survey – IX. CFHT ESPaDOnS spectroscopic analysis of 115 bright metal-poor candidate stars

The Pristine survey – IX. CFHT ESPaDOnS spectroscopic analysis of 115 bright metal-poor candidate stars

Li abundances for solar twins in the open cluster M67

The hot Jupiter of the magnetically active weak-line T Tauri star V830 Tau

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