THE 2MASS WIDE-FIELD T DWARF SEARCH. II. DISCOVERY OF
... not seen in the OSIRIS images; these are listed in Table 1, with updated designations and photometry from the 2MASS All Sky Data Release (2MASS ADR; Cutri et al. 2003). A few sources were identified as unflagged image artifacts arising from electronic feedback in the quadrant readout of the 2MASS NICM ...
... not seen in the OSIRIS images; these are listed in Table 1, with updated designations and photometry from the 2MASS All Sky Data Release (2MASS ADR; Cutri et al. 2003). A few sources were identified as unflagged image artifacts arising from electronic feedback in the quadrant readout of the 2MASS NICM ...
Properties of White Dwarfs, Teacher Guide
... Some background: Sirius is a nearby star – only 9 light-years away. All stars in our Galaxy orbit the Galactic barycenter, so they are all moving. Astronomers detect and track the motion of stars relative to our Sun. There are two motions that can be measured: radial velocity (in the line of sight) ...
... Some background: Sirius is a nearby star – only 9 light-years away. All stars in our Galaxy orbit the Galactic barycenter, so they are all moving. Astronomers detect and track the motion of stars relative to our Sun. There are two motions that can be measured: radial velocity (in the line of sight) ...
The low-mass dispersed population around the Lupus clouds
... objects (e.g. Neuhäuser & Comerón 1999). The CaII triplet absorption lines at 8498 Å, 8542 Å and 8662 Å are very prominent in K and early-M giants (Kirkpatrick et al. 1991), thus providing a straightforward criterion for discriminating between background contaminants and candidate members of the s ...
... objects (e.g. Neuhäuser & Comerón 1999). The CaII triplet absorption lines at 8498 Å, 8542 Å and 8662 Å are very prominent in K and early-M giants (Kirkpatrick et al. 1991), thus providing a straightforward criterion for discriminating between background contaminants and candidate members of the s ...
White dwarf binary
... White dwarfs White dwarf limit White dwarf binary Accretion disks Thought question Nova Thought question 2 types of SN Nova or supernova? Standard candles Neutron stars Discovery Crab pulsar Pulsars Pulsars are NS! Magnetic fields Thought question Binaries Spin up Thought question ...
... White dwarfs White dwarf limit White dwarf binary Accretion disks Thought question Nova Thought question 2 types of SN Nova or supernova? Standard candles Neutron stars Discovery Crab pulsar Pulsars Pulsars are NS! Magnetic fields Thought question Binaries Spin up Thought question ...
Search For Gas Giants Around Late-m Dwarfs - STARS
... We carried out a near-infrared radial velocity search for Jupiter-mass planets around 36 late M dwarfs. This survey was the first of its kind undertaken to monitor radial velocity variability of these faint dwarfs. For this unique survey we employed the 10-m Keck II on Mauna Kea in Hawaii. With a re ...
... We carried out a near-infrared radial velocity search for Jupiter-mass planets around 36 late M dwarfs. This survey was the first of its kind undertaken to monitor radial velocity variability of these faint dwarfs. For this unique survey we employed the 10-m Keck II on Mauna Kea in Hawaii. With a re ...
Quiescent and flaring X-ray emission from the nearby M/T dwarf
... Spectrometer) detectors is rather weak; while we clearly see a few photons from prominent emission lines, e.g. O viii at 19 Å and O vii at 21.6–22.1 Å, the RGS spectra are not suitable for a quantitative analysis. Thus we considered only X-ray data taken with the EPIC (European Photon Imaging Camera ...
... Spectrometer) detectors is rather weak; while we clearly see a few photons from prominent emission lines, e.g. O viii at 19 Å and O vii at 21.6–22.1 Å, the RGS spectra are not suitable for a quantitative analysis. Thus we considered only X-ray data taken with the EPIC (European Photon Imaging Camera ...
Consistent metallicity scale for cool dwarfs and giants
... Aims. It is therefore crucial to understand whether the metallicity or abundance differences among dwarfs and giants are real or are produced by systematic errors in the analysis. We aim to ascertain a methodology capable of producing a consistent metallicity scale for giants and dwarfs. Methods. To ...
... Aims. It is therefore crucial to understand whether the metallicity or abundance differences among dwarfs and giants are real or are produced by systematic errors in the analysis. We aim to ascertain a methodology capable of producing a consistent metallicity scale for giants and dwarfs. Methods. To ...
astro-ph/0301519 PDF
... We find that the presence or absence of heavy elements in the hot DA white dwarfs largely reflects what would be expected if radiative levitation is the supporting mechanism, although the measured abundances do not match the predicted values very well, as reported by other authors in the past. Almos ...
... We find that the presence or absence of heavy elements in the hot DA white dwarfs largely reflects what would be expected if radiative levitation is the supporting mechanism, although the measured abundances do not match the predicted values very well, as reported by other authors in the past. Almos ...
SPIRou Science Case
... of a giant planet around 51 Peg (Mayor & Queloz 1995, Nature 378, 355), about 1,000 extra-solar planets have now been detected, revolutionizing planetary science by placing our unique solar system into a much broader context. More specifically, these discoveries allow us to explore the surprising di ...
... of a giant planet around 51 Peg (Mayor & Queloz 1995, Nature 378, 355), about 1,000 extra-solar planets have now been detected, revolutionizing planetary science by placing our unique solar system into a much broader context. More specifically, these discoveries allow us to explore the surprising di ...
UK Exoplanet community meeting 2017
... Earth is the best studied planet we know. A century’s work on terrestrial samples has interrogated 90% of its history, and revealed the physics of processes from the formation of the core to the rise of atmospheric oxygen. This detailed understanding can benefit our perspective of exo-planetary syst ...
... Earth is the best studied planet we know. A century’s work on terrestrial samples has interrogated 90% of its history, and revealed the physics of processes from the formation of the core to the rise of atmospheric oxygen. This detailed understanding can benefit our perspective of exo-planetary syst ...
Full Programme and Abstracts - UK Exoplanet community meeting
... Earth is the best studied planet we know. A century’s work on terrestrial samples has interrogated 90% of its history, and revealed the physics of processes from the formation of the core to the rise of atmospheric oxygen. This detailed understanding can benefit our perspective of exo-planetary syst ...
... Earth is the best studied planet we know. A century’s work on terrestrial samples has interrogated 90% of its history, and revealed the physics of processes from the formation of the core to the rise of atmospheric oxygen. This detailed understanding can benefit our perspective of exo-planetary syst ...
The size and shape of the Milky Way disc and halo from M
... Counting stars in our Galaxy has long been used to infer its structure. This is mostly done with relatively luminous stars due to insufficient data on substellar objects. Early work has been done by Kapteyn (1922), Seares et al. (1925) and Oort (1938) who used this method to determine the geometrica ...
... Counting stars in our Galaxy has long been used to infer its structure. This is mostly done with relatively luminous stars due to insufficient data on substellar objects. Early work has been done by Kapteyn (1922), Seares et al. (1925) and Oort (1938) who used this method to determine the geometrica ...
Article PDF - IOPscience
... indicators, the white dwarf population sampled must be as close as possible to being statistically complete. The white dwarf population is composed mainly of lowluminosity stars that are rather difficult to study as we move further away from the Sun. Candidates are mainly discovered from either prop ...
... indicators, the white dwarf population sampled must be as close as possible to being statistically complete. The white dwarf population is composed mainly of lowluminosity stars that are rather difficult to study as we move further away from the Sun. Candidates are mainly discovered from either prop ...
Cataclysmic Cosmic Events and How to Observe Them www.springer.com/series/5338
... their violence and energy output. Active galaxies, containing supermassive black holes at their centers, can swallow a solar mass every month, releasing huge amounts of energy that amateur astronomers can observe as a fluctuation in light output. The luminosity of some of these objects is truly mind ...
... their violence and energy output. Active galaxies, containing supermassive black holes at their centers, can swallow a solar mass every month, releasing huge amounts of energy that amateur astronomers can observe as a fluctuation in light output. The luminosity of some of these objects is truly mind ...
- ANU Repository
... There have been several recent works estimating the occurrence of planets around M dwarfs, the distribution with radii, and the number of planets within a ‘habitable zone’ (HZ) bounded by minimum and maximum irradiance levels. Both Dressing & Charbonneau (2013, hereafter, DC13) and Gaidos (2013, her ...
... There have been several recent works estimating the occurrence of planets around M dwarfs, the distribution with radii, and the number of planets within a ‘habitable zone’ (HZ) bounded by minimum and maximum irradiance levels. Both Dressing & Charbonneau (2013, hereafter, DC13) and Gaidos (2013, her ...
A re-appraisal of the habitability of planets around M dwarf
... which are designated as lowercase m, and absolute magnitudes, which are designated as uppercase M and defined as the apparent magnitude that a star would have if it were at a distance of 10 pc (!33 light years) from the observer. Observations were historically made with the naked eye, then eyes with ...
... which are designated as lowercase m, and absolute magnitudes, which are designated as uppercase M and defined as the apparent magnitude that a star would have if it were at a distance of 10 pc (!33 light years) from the observer. Observations were historically made with the naked eye, then eyes with ...
A Reappraisal of The Habitability of Planets around M Dwarf Stars
... which are designated as lowercase m, and absolute magnitudes, which are designated as uppercase M and defined as the apparent magnitude that a star would have if it were at a distance of 10 pc (33 light years) from the observer. Observations were historically made with the naked eye, then eyes with ...
... which are designated as lowercase m, and absolute magnitudes, which are designated as uppercase M and defined as the apparent magnitude that a star would have if it were at a distance of 10 pc (33 light years) from the observer. Observations were historically made with the naked eye, then eyes with ...
Rocky planetesimals as the origin of metals in DZ stars
... has expanded the number of confirmed, unique DZ stars to 146, providing effective temperatures, calcium abundances and photometric distances under the assumption of log [g(cm s−2 )] = 8.0. Of these 288 cool, helium-rich white dwarfs in DR4, only one was known previously; G111-54 or SDSS J080537.64+3 ...
... has expanded the number of confirmed, unique DZ stars to 146, providing effective temperatures, calcium abundances and photometric distances under the assumption of log [g(cm s−2 )] = 8.0. Of these 288 cool, helium-rich white dwarfs in DR4, only one was known previously; G111-54 or SDSS J080537.64+3 ...
Direct Imaging Searches Around White Dwarfs - X
... progenitors: early-type stars (B,A,F), intermediate masses (1.5
... progenitors: early-type stars (B,A,F), intermediate masses (1.5
Hot DQ White Dwarfs: Something Different
... by a thin envelope of helium (and hydrogen) that has survived the nuclear burning and mass loss phase. The core, which is essentially the result of the fusion of light elements, has a composition that depends on the initial mass of the star. For very low mass stars that could not ignite helium, it i ...
... by a thin envelope of helium (and hydrogen) that has survived the nuclear burning and mass loss phase. The core, which is essentially the result of the fusion of light elements, has a composition that depends on the initial mass of the star. For very low mass stars that could not ignite helium, it i ...
Clouds and Chemistry in the Atmosphere of Extrasolar Planet
... Using the integral field spectrograph OSIRIS, on the Keck II telescope, broad near-infrared H and Kband spectra of the young exoplanet HR8799b have been obtained. In addition, six new narrow-band photometric measurements have been taken across the H and K bands. These data are combined with previous ...
... Using the integral field spectrograph OSIRIS, on the Keck II telescope, broad near-infrared H and Kband spectra of the young exoplanet HR8799b have been obtained. In addition, six new narrow-band photometric measurements have been taken across the H and K bands. These data are combined with previous ...
Science drivers for GLAO at LBT
... and separation and formation cluster density of binary brown dwarfs. They show that most known wide binary brown dwarfs are young (open circles) and will likely be dissolved in their natal clusters before they join the field (old) population (open stars). ...
... and separation and formation cluster density of binary brown dwarfs. They show that most known wide binary brown dwarfs are young (open circles) and will likely be dissolved in their natal clusters before they join the field (old) population (open stars). ...
Brown dwarf
Brown dwarfs are substellar objects not massive enough to sustain hydrogen-1 fusion reactions in their cores, unlike main-sequence stars. They occupy the mass range between the heaviest gas giants and the lightest stars, with an upper limit around 75 to 80 Jupiter masses (MJ). Brown dwarfs heavier than about 13 MJ are thought to fuse deuterium and those above ~65 MJ, fuse lithium as well. Brown dwarfs may be fully convective, with no layers or chemical differentiation by depth.The defining differences between a very-low-mass brown dwarf and a giant planet (~13 MJ) are debated. One school of thought is based on formation; the other, on the physics of the interior.Part of the debate concerns whether ""brown dwarfs"" must, by definition, have experienced fusion at some point in their history.Stars are categorized by spectral class, with brown dwarfs being designated as types M, L, T, and Y. Despite their name, brown dwarfs are of different colors. Many brown dwarfs would likely appear magenta to the human eye, or possibly orange/red. Brown dwarfs are not very luminous at visible wavelengths.Some planets are known to orbit brown dwarfs: 2M1207b, MOA-2007-BLG-192Lb, and 2MASS J044144bAt a distance of about 6.5 light years, the nearest known brown dwarf is Luhman 16, a binary system of brown dwarfs discovered in 2013. One brown dwarf, DENIS-P J082303.1-491201 b, from an ultracool binary system, has a mass of about 28 MJ, making it the largest known exoplanet (as of March 2014).