Microlensing Events by Proxima Centauri in 2014 and 2016
... To refine the impact parameters and times of closest approach, we obtained Hubble Space Telescope (HST ) images of the field on 2012 October 1. Observations were taken with the UVIS channel of the Wide Field Camera 3 (WFC3) in the F475W, F555W, F606W, and F814W filters. Since the background stars ar ...
... To refine the impact parameters and times of closest approach, we obtained Hubble Space Telescope (HST ) images of the field on 2012 October 1. Observations were taken with the UVIS channel of the Wide Field Camera 3 (WFC3) in the F475W, F555W, F606W, and F814W filters. Since the background stars ar ...
The Circumstellar Environments of Young Stars at AU Scales
... here referred to as optical interferometry. An interferometer with a baseline length of B = 100 m (typical of current facilities) operating at near to mid-infrared wavelengths (NIR, MIR, typically H to N bands, λ0 = 1.65 − 10 µm) probes 1800 − 300 K material and achieves an angular resolution ∼ λ0 / ...
... here referred to as optical interferometry. An interferometer with a baseline length of B = 100 m (typical of current facilities) operating at near to mid-infrared wavelengths (NIR, MIR, typically H to N bands, λ0 = 1.65 − 10 µm) probes 1800 − 300 K material and achieves an angular resolution ∼ λ0 / ...
A spectroscopic investigation of the O
... intense survey of the stars but also a good time sampling to constrain the short- as well as the long-period systems. This monitoring has to be as homogeneous as possible because combining data from the literature may provide erroneous results. Indeed, the literature (especially the older papers) of ...
... intense survey of the stars but also a good time sampling to constrain the short- as well as the long-period systems. This monitoring has to be as homogeneous as possible because combining data from the literature may provide erroneous results. Indeed, the literature (especially the older papers) of ...
Dust in Proto-Planetary Disks: Properties and Evolution
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
Dust in Proto-Planetary Disks: Properties and Evolution
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
a0041_Spectral Analysis and Classification of Herbig A
... Optical spectra were obtained for 75 of the 99 stars in the Herbig and Bell Catalog (HBC; Herbig & Bell 1988) having spectral types B, A, and F. Observations were made during 1999 July and 2000 January using the 1.5 m telescope of the Whipple Observatory with the FAST Spectrograph (Fabricant et al. ...
... Optical spectra were obtained for 75 of the 99 stars in the Herbig and Bell Catalog (HBC; Herbig & Bell 1988) having spectral types B, A, and F. Observations were made during 1999 July and 2000 January using the 1.5 m telescope of the Whipple Observatory with the FAST Spectrograph (Fabricant et al. ...
arXiv:astro-ph/0701557v1 19 Jan 2007
... We investigate the stellar populations in the star forming ring of the luminous infrared galaxy NGC 7469. We use Hubble Space Telescope multi-wavelength (UV through NIR) imaging complemented with new K-band ground-based long-slit spectroscopy, and mid-IR and radio maps from the literature. Spectral ...
... We investigate the stellar populations in the star forming ring of the luminous infrared galaxy NGC 7469. We use Hubble Space Telescope multi-wavelength (UV through NIR) imaging complemented with new K-band ground-based long-slit spectroscopy, and mid-IR and radio maps from the literature. Spectral ...
Photospheric activity, rotation, and star
... ias.u-psud.fr/). More information on the instrument, its operation, and performance can be found in Auvergne et al. (2009). The transits are removed from the light curve using the ephemeris of Fridlund et al. (2010) and the out-of-transit data are binned by computing average flux values along each o ...
... ias.u-psud.fr/). More information on the instrument, its operation, and performance can be found in Auvergne et al. (2009). The transits are removed from the light curve using the ephemeris of Fridlund et al. (2010) and the out-of-transit data are binned by computing average flux values along each o ...
Stellar Remnants White Dwarfs Type Ia Supernovae Neutron Stars
... White Dwarf Density • size R ~ thousands of kilometers • mass M ~ mass of stars • density absurdly high: – white dwarf matter is roughly a million times denser than water – instead of weighing a gram, an ice cube block of white dwarf material would weigh a ton. ...
... White Dwarf Density • size R ~ thousands of kilometers • mass M ~ mass of stars • density absurdly high: – white dwarf matter is roughly a million times denser than water – instead of weighing a gram, an ice cube block of white dwarf material would weigh a ton. ...
PDF only - at www.arxiv.org.
... Abstract: The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five dif ...
... Abstract: The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five dif ...
Plotting the Rotation Curve of M31
... Questions to ask the class before the activity: What is the Universe composed of? Answer: energy, luminous matter, dark matter, dark energy. What are galaxies? Answer: large collections of stars. They vary in their morphology and stellar composition i.e. ellipticals are red and contain older stars t ...
... Questions to ask the class before the activity: What is the Universe composed of? Answer: energy, luminous matter, dark matter, dark energy. What are galaxies? Answer: large collections of stars. They vary in their morphology and stellar composition i.e. ellipticals are red and contain older stars t ...
Krypton in presolar mainstream SiC grains from AGB stars
... (80 Kr/82 Kr)G anticorrelation is that AGB stars with an initial mass of 3 M produce coarse SiC grains, whereas AGB stars with an initial mass of 1.5 M produce fine SiC grains. In Fig. 4 we report the Kr−S isotopic ratios predicted at the last third dredge−up episode (25th TP) for an AGB star with ...
... (80 Kr/82 Kr)G anticorrelation is that AGB stars with an initial mass of 3 M produce coarse SiC grains, whereas AGB stars with an initial mass of 1.5 M produce fine SiC grains. In Fig. 4 we report the Kr−S isotopic ratios predicted at the last third dredge−up episode (25th TP) for an AGB star with ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.