All Outputs (129)

A kinematically unbiased search for nearby young stars in the Northern hemisphere selected using SuperWASP rotation periods (2015)
Journal Article
Binks, A., Jeffries, R., & Maxted, P. (2015). A kinematically unbiased search for nearby young stars in the Northern hemisphere selected using SuperWASP rotation periods. Monthly Notices of the Royal Astronomical Society, 452(1), 173-192. https://doi.org/10.1093/mnras/stv1309

We present a kinematically-unbiased search to identify young, nearby low-mass members of kinematic moving groups (MGs). Objects with both rotation periods shorter than 5 days in the SuperWASP All-Sky Survey and X-ray counterparts in the ROSAT All-Sky... Read More about A kinematically unbiased search for nearby young stars in the Northern hemisphere selected using SuperWASP rotation periods.

The Gaia-ESO Survey: N-body modelling of the Gamma Velorum cluster (2015)
Journal Article
Mapelli, M., Vallenari, A., Jeffries, R. D., Gavagnin, E., Cantat-Gaudin, T., Sacco, G. G., …Worley, C. C. (2015). The Gaia-ESO Survey: N-body modelling of the Gamma Velorum cluster. Astronomy & Astrophysics, 578, A35. https://doi.org/10.1051/0004-6361/201425514

The Gaia-ESO Survey has recently unveiled the complex kinematic signature of the Gamma Velorum cluster: this cluster is composed of two kinematically distinct populations (hereafter, population A and B), showing two different velocity dispersions and... Read More about The Gaia-ESO Survey: N-body modelling of the Gamma Velorum cluster.

Gaia-ESO Survey: Analysis of pre-main sequence stellar spectra (2015)
Journal Article
Lanzafame, A. C., Frasca, A., Damiani, F., Franciosini, E., Cottaar, M., Sousa, S. G., …Zaggia, S. (2015). Gaia-ESO Survey: Analysis of pre-main sequence stellar spectra. Astronomy & Astrophysics, 576, Article A80. https://doi.org/10.1051/0004-6361/201424759

Context. The Gaia-ESO Public Spectroscopic Survey is obtaining high-quality spectroscopy of some 100 000 Milky Way stars using the FLAMES spectrograph at the VLT, down to V = 19 mag, systematically covering all the main components of the Milky Way an... Read More about Gaia-ESO Survey: Analysis of pre-main sequence stellar spectra.

The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo (2015)
Journal Article
Jeffries. (2015). The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/201425554

A small fraction of the halo field is made up of stars that share the light element (Z = 13) anomalies characteristic of second generation globular cluster (GC) stars. The ejected stars shed light on the formation of the Galactic halo by tracing the... Read More about The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo.

TheGaia-ESO Survey: Chromospheric emission, accretion properties, and rotation inγVelorum and Chamaeleon I (2015)
Journal Article
Frasca, A., Biazzo, K., Lanzafame, A. C., Alcalá, J. M., Brugaletta, E., Klutsch, A., …Worley, C. C. (2015). TheGaia-ESO Survey: Chromospheric emission, accretion properties, and rotation inγVelorum and Chamaeleon I. Astronomy & Astrophysics, 575, A4. https://doi.org/10.1051/0004-6361/201424409

Aims. One of the goals of the Gaia-ESO Survey (GES), which is conducted with FLAMES at the VLT, is the census and the characterization of the low-mass members of very young clusters and associations. We conduct a comparative study of the main propert... Read More about TheGaia-ESO Survey: Chromospheric emission, accretion properties, and rotation inγVelorum and Chamaeleon I.

The Gaia-ESO survey: Discovery of a spatially extended low-mass population in the Vela OB2 association (2015)
Journal Article
Jeffries. (2015). The Gaia-ESO survey: Discovery of a spatially extended low-mass population in the Vela OB2 association. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/201425367

The nearby (distance ~ 350–400 pc), rich Vela OB2 association, includes ?2 Velorum, one of the most massive binaries in the solar neighbourhood and an excellent laboratory for investigating the formation and early evolution of young clusters. Recent... Read More about The Gaia-ESO survey: Discovery of a spatially extended low-mass population in the Vela OB2 association.

The Gaia-ESO Survey: Kinematics of seven Galactic globular clusters (2015)
Journal Article
Lardo, C., Pancino, E., Bellazzini, M., Bragaglia, A., Donati, P., Gilmore, G., …Worley, C. C. (2015). The Gaia-ESO Survey: Kinematics of seven Galactic globular clusters. Astronomy & Astrophysics, 573, Article A115. https://doi.org/10.1051/0004-6361/201425036

The Gaia-ESO survey is a large public spectroscopic survey aimed at investigating the origin and formation history of our Galaxy by collecting spectroscopy of representative samples (about 105 Milky Way stars) of all Galactic stellar populations, in... Read More about The Gaia-ESO Survey: Kinematics of seven Galactic globular clusters.

The Gaia-ESO Survey: CNO abundances in the open clusters Trumpler 20, NGC 4815, and NGC 6705 (2015)
Journal Article
Jeffries. (2015). The Gaia-ESO Survey: CNO abundances in the open clusters Trumpler 20, NGC 4815, and NGC 6705. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/201424989

Context. The Gaia-ESO Public Spectroscopic Survey will observe a large sample of clusters and cluster stars, covering a wide age-distance-metallicity-position-density parameter space. Aims. We aim to determine C, N, and O abundances in stars of Ga... Read More about The Gaia-ESO Survey: CNO abundances in the open clusters Trumpler 20, NGC 4815, and NGC 6705.

Pre-main-sequence isochrones - III: The Cluster Collaboration isochrone server (2014)
Journal Article
Jeffries. (2014). Pre-main-sequence isochrones - III: The Cluster Collaboration isochrone server. Monthly Notices of the Royal Astronomical Society, 3496 - 3511. https://doi.org/10.1093/mnras/stu1944

We present an isochrone server for semi-empirical pre-main-sequence model isochrones in the following systems: Johnson–Cousins, Sloan Digital Sky Survey, Two-Micron All-Sky Survey, Isaac Newton Telescope (INT) Wide-Field Camera and INT Photometric Ha... Read More about Pre-main-sequence isochrones - III: The Cluster Collaboration isochrone server.

Using rotation, magnetic activity and lithium to estimate the ages of low mass stars (2014)
Journal Article
Jeffries, R. (2014). Using rotation, magnetic activity and lithium to estimate the ages of low mass stars. EAS Publications Series, 65, 289-325. https://doi.org/10.1051/eas/1465008

The rotation rate, level of magnetic activity and surface lithium abundance are age-dependent quantities in stars of about a solar mass and below. The physical reasons for the evolution of these phenomena are qualitatively understood, but accurate qu... Read More about Using rotation, magnetic activity and lithium to estimate the ages of low mass stars.

The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars (2014)
Journal Article
Smiljanic, R., Korn, A., Bergemann, M., Frasca, A., Magrini, L., Masseron, T., …Zaggia, S. (2014). The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars. Astronomy and Astrophysics, 570, Article A122. https://doi.org/10.1051/0004-6361/201423937

Context. The ongoing Gaia-ESO Public Spectroscopic Survey is using FLAMES at the VLT to obtain high-quality medium-resolution Giraffe spectra for about 105 stars and high-resolution UVES spectra for about 5000 stars. With UVES, the Survey has already... Read More about The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars.

The Gaia-ESO Survey: Metallicity of the Chamaeleon I star-forming region (2014)
Journal Article
Spina, L., Randich, S., Palla, F., Biazzo, K., Sacco, G. G., Alfaro, E. J., …Worley, C. C. (2014). The Gaia-ESO Survey: Metallicity of the Chamaeleon I star-forming region. Astronomy & Astrophysics, 568, A2. https://doi.org/10.1051/0004-6361/201424135

Context. Recent metallicity determinations in young open clusters and star-forming regions suggest that the latter may be characterized by a slightly lower metallicity than the Sun and older clusters in the solar vicinity. However, these results are... Read More about The Gaia-ESO Survey: Metallicity of the Chamaeleon I star-forming region.

The Gaia-ESO Survey: the first abundance determination of the pre-main-sequence cluster gamma Velorum (2014)
Journal Article
Spina, L., Randich, S., Palla, F., Sacco, G. G., Magrini, L., Franciosini, E., …Worley, C. (2014). The Gaia-ESO Survey: the first abundance determination of the pre-main-sequence cluster gamma Velorum. Astronomy & Astrophysics, 567, Article A55. https://doi.org/10.1051/0004-6361/201423527

Context. Knowledge of the abundance distribution of star forming regions and young clusters is critical to investigate a variety of issues, from triggered star formation and chemical enrichment by nearby supernova explosions to the ability to form pl... Read More about The Gaia-ESO Survey: the first abundance determination of the pre-main-sequence cluster gamma Velorum.

The Gaia-ESO Survey: the Galactic thick to thin disc transition (2014)
Journal Article
Recio-Blanco, A., de Laverny, P., Kordopatis, G., Helmi, A., Hill, V., Gilmore, G., …Maiorca, E. (2014). The Gaia-ESO Survey: the Galactic thick to thin disc transition. Astronomy & Astrophysics, 567, Article A5. https://doi.org/10.1051/0004-6361/201322944

Aims. The nature of the thick disc and its relation to the thin disc is presently an important subject of debate. In fact, the structural and chemo-dynamical transition between disc populations can be used as a test of the proposed models of Galactic... Read More about The Gaia-ESO Survey: the Galactic thick to thin disc transition.

The effect of star-spots on the ages of low-mass stars determined from the lithium depletion boundary (2014)
Journal Article
Jackson, R. J., & Jeffries, R. D. (2014). The effect of star-spots on the ages of low-mass stars determined from the lithium depletion boundary. Monthly Notices of the Royal Astronomical Society, 445(4), 2111-2123. https://doi.org/10.1093/mnras/stu2076

In a coeval group of low-mass stars, the luminosity of the sharp transition between stars that retain their initial lithium and those at slightly higher masses in which Li has been depleted by nuclear reactions, the lithium depletion boundary (LDB),... Read More about The effect of star-spots on the ages of low-mass stars determined from the lithium depletion boundary.

Gaia-ESO Survey: Empirical classification of VLT/Giraffe stellar spectra in the wavelength range 6440–6810 Å in theγVelorum cluster, and calibration of spectral indices (2014)
Journal Article
Damiani, F., Prisinzano, L., Micela, G., Randich, S., Gilmore, G., Drew, J. E., …Maiorca, E. (2014). Gaia-ESO Survey: Empirical classification of VLT/Giraffe stellar spectra in the wavelength range 6440–6810 Å in theγVelorum cluster, and calibration of spectral indices. Astronomy and Astrophysics, 566, A50. https://doi.org/10.1051/0004-6361/201323306

We present a study of spectral diagnostics available from optical spectra with R = 17 000 obtained with the VLT/Giraffe HR15n setup, using observations from the Gaia-ESO Survey, on the γ Vel young cluster, with the purpose of classifying these stars... Read More about Gaia-ESO Survey: Empirical classification of VLT/Giraffe stellar spectra in the wavelength range 6440–6810 Å in theγVelorum cluster, and calibration of spectral indices.

The Gaia-ESO Survey: processing FLAMES-UVES spectra (2014)
Journal Article
Sacco, G. G., Morbidelli, L., Franciosini, E., Maiorca, E., Randich, S., Modigliani, A., …Worley, C. (2014). The Gaia-ESO Survey: processing FLAMES-UVES spectra. Astronomy & Astrophysics, 565, A113. https://doi.org/10.1051/0004-6361/201423619

The Gaia-ESO Survey is a large public spectroscopic survey that aims to derive radial velocities and fundamental parameters of about 105 Milky Way stars in the field and in clusters. Observations are carried out with the multi-object optical spectrog... Read More about The Gaia-ESO Survey: processing FLAMES-UVES spectra.

The effect of starspots on the radii of low-mass pre-main-sequence stars (2014)
Journal Article
Jackson, R. J., & Jeffries, R. D. (2014). The effect of starspots on the radii of low-mass pre-main-sequence stars. Monthly Notices of the Royal Astronomical Society, 441(3), 2111-2123. https://doi.org/10.1093/mnras/stu651

A polytropic model is used to investigate the effects of dark photospheric spots on the evolution and radii of magnetically active, low-mass (M < 0.5 M⊙), pre-main-sequence (PMS) stars. Spots slow the contraction along Hayashi tracks and inflate the... Read More about The effect of starspots on the radii of low-mass pre-main-sequence stars.

The Gaia-ESO Survey: radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk (2014)
Journal Article
Bergemann, M., Ruchti, G. R., Serenelli, A., Feltzing, S., Alves-Brito, A., Asplund, M., …Tautvaišienė, G. (2014). The Gaia-ESO Survey: radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk. Astronomy & Astrophysics, 565, Article A89. https://doi.org/10.1051/0004-6361/201423456

We study the relationship between age, metallicity, and α-enhancement of FGK stars in the Galactic disk. The results are based upon the analysis of high-resolution UVES spectra from the Gaia-ESO large stellar survey. We explore the limitations of the... Read More about The Gaia-ESO Survey: radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk.

AN ANOMALOUS EXTINCTION LAW IN THE Cep OB3b YOUNG CLUSTER: EVIDENCE FOR DUST PROCESSING DURING GAS DISPERSAL (2014)
Journal Article
Allen, T. S., Prchlik, J. J., Megeath, S. T., Gutermuth, R. A., Pipher, J. L., Naylor, T., & Jeffries, R. D. (2014). AN ANOMALOUS EXTINCTION LAW IN THE Cep OB3b YOUNG CLUSTER: EVIDENCE FOR DUST PROCESSING DURING GAS DISPERSAL. Astrophysical Journal, 786(2), 113. https://doi.org/10.1088/0004-637x/786/2/113

We determine the extinction law through Cep OB3b, a young cluster of 3000 stars undergoing gas dispersal. The extinction is measured toward 76 background K giants identified with MMT/Hectospec spectra. Color excess ratios were determined toward each... Read More about AN ANOMALOUS EXTINCTION LAW IN THE Cep OB3b YOUNG CLUSTER: EVIDENCE FOR DUST PROCESSING DURING GAS DISPERSAL.