8 research outputs found
Juggling Priorities: Female Mating Tactics in P hayre's Leaf Monkeys
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91119/1/ajp22004.pd
Weighing stars from birth to death : mass determination methods across the HRD
Funding: C.A., J.S.G.M., and M.G.P. received funding from the European Research Council (ERC) under the European Unionâs Horizon 2020 research and innovation programme (grant agreement No 670519: MAMSIE). N.B. gratefully acknowledge financial support from the Royal Society (University Research Fellowships) and from the European Research Council (ERC-CoG-646928, Multi-Pop).The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between [0.3 ,2 ]% for the covered mass range of M â[0.1 ,16 ] Mâ , 75 % of which are stars burning hydrogen in their core and the other 25 % covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a "mass-ladder" for stars.PostprintPeer reviewe
Weighing stars from birth to death: mass determination methods across the HRD
The mass of a star is the most fundamental parameter for its structure,
evolution, and final fate. It is particularly important for any kind of stellar
archaeology and characterization of exoplanets. There exists a variety of
methods in astronomy to estimate or determine it. In this review we present a
significant number of such methods, beginning with the most direct and
model-independent approach using detached eclipsing binaries. We then move to
more indirect and model-dependent methods, such as the quite commonly used
isochrone or stellar track fitting. The arrival of quantitative
asteroseismology has opened a completely new approach to determine stellar
masses and to complement and improve the accuracy of other methods. We include
methods for different evolutionary stages, from the pre-main sequence to
evolved (super)giants and final remnants. For all methods uncertainties and
restrictions will be discussed. We provide lists of altogether more than 200
benchmark stars with relative mass accuracies between for the
covered mass range of M\in [0.1,16]\,\msun, of which are stars burning
hydrogen in their core and the other covering all other evolved stages.
We close with a recommendation how to combine various methods to arrive at a
"mass-ladder" for stars.Comment: Invited review article for The Astronomy and Astrophysics Review. 146
pages, 16 figures, 11 tables. Accepted version by the Journal. It includes
summary figure of accuracy/precision of methods for mass ranges and summary
table for individual method
Weighing stars from birth to death: mass determination methods across the HRD
The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between [0.3,2]% for the covered mass range of Mâ[0.1,16]Mâ, 75% of which are stars burning hydrogen in their core and the other 25% covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a âmass-ladderâ for stars.Instituto de AstrofĂsica de La Plat
FECAL CORTICOID MONITORING IN WHOOPING CRANES TRAINED TO FOLLOW ULTRALIGHT AIRCRAFT
The use of fecal corticoid assays to measure stress in North American cranes has been limited to laboratory validation and a single field project involving reintroduced sandhill cranes (Ludders et al., 1998, 2001; Hartup et al., 2004). In 2001, we documented trends in corticoid concentrations among a cohort of ten costume-reared whooping cranes subjected to ultralight aircraft training and migration. All samples were analyzed by a validated corticosterone 125I radioimmunoassay for determination of corticoid levels. Fecal corticoid concentrations in chicks exhibited a logarithmic decline over the first 14 days after hatching (r = 0.86, p \u3c 0.001). Fecal corticoid concentrations then stabilized at baseline levels (median 68 ng/g, range 17â186 ng/g, n = 116) during the subsequent six weeks of costume-rearing and aircraft habituation in captivity. Fecal corticoid concentrations of eight cranes increased 8-34 fold during shipment in crates to Wisconsin for field training. Increases in fecal corticoid concentrations were positively correlated with age (r = 0.81, p = 0.01), but not body weight (r = 0.44, p = 0.28) at the time of shipping. Fecal corticoid concentrations returned to baseline levels within seven days, and were sustained throughout the remainder of the training period (median 77 ng/g, range 22â 292 ng/g, n=190). Elevations in fecal corticoid concentrations were observed one (p = 0.035) and four days (p = 0.003) following physical examination and placement of leg bands compared to three days prior to the procedures (median 176 ng/g, range 116 â 553 ng/g, n = 19). Fecal corticoid concentrations decreased to pre-procedure levels within seven days. Fecal corticoid concentrations and variation during the 50 day migration period were similar to training levels in Wisconsin, except for a one day increase observed following a violent storm and escape from the temporary holding pen the preceding night (median 243 ng/g, range 228 â 280 ng/g, n = 7). There was an overall decline in fecal corticoid concentrations from the cranes during the migration (r = 0.42, p \u3c 0.001). Acute stressors such as capture and restraint and severe storms were associated with stress responses by the cranes that varied in accordance with lasting physical or psychological stimuli. The overall process of costume-rearing, ultralight aircraft habituation, training and artificial migration was not associated with elevations in fecal corticoid concentrations suggestive of chronic stress
Weighing stars from birth to death: mass determination methods across the HRD
The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between [0.3 , 2] % for the covered mass range of Mâ[0.1,16]Mâ, 75 % of which are stars burning hydrogen in their core and the other 25 % covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a âmass-ladderâ for stars
Weighing stars from birth to death:mass determination methods across the HRD
The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between [0.3 ,2 ]% for the covered mass range of M â[0.1 ,16 ] Mâ , 75 % of which are stars burning hydrogen in their core and the other 25 % covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a "mass-ladder" for stars