Age aspects of habitability - Cambridge University Press
... Abstract: A ‘habitable zone’ of a star is defined as a range of orbits within which a rocky planet can support liquid water on its surface. The most intriguing question driving the search for habitable planets is whether they host life. But is the age of the planet important for its habitability? If ...
... Abstract: A ‘habitable zone’ of a star is defined as a range of orbits within which a rocky planet can support liquid water on its surface. The most intriguing question driving the search for habitable planets is whether they host life. But is the age of the planet important for its habitability? If ...
Chapter 09 - The Independent School
... Binary Stars More than 50 % of all stars in our Milky Way are not single stars, but belong to binaries: Pairs or multiple systems of stars which orbit their common center of mass. If we can measure and understand their orbital motion, we can estimate the stellar ...
... Binary Stars More than 50 % of all stars in our Milky Way are not single stars, but belong to binaries: Pairs or multiple systems of stars which orbit their common center of mass. If we can measure and understand their orbital motion, we can estimate the stellar ...
Toward a revival of Stellar Intensity Interferometry
... high-speed photon-counting instrument. The entrance pupil can be optically sliced into a hundred segments, each feeding a separate detector. Different means of electronically combining the signal in software would yield either a photometric signal of very high time-resolution using the collecting ar ...
... high-speed photon-counting instrument. The entrance pupil can be optically sliced into a hundred segments, each feeding a separate detector. Different means of electronically combining the signal in software would yield either a photometric signal of very high time-resolution using the collecting ar ...
Star Classification and its Connection to Exoplanets.
... Before the conclusion, there is a specific bias in all of the results reached in this experiment: because current methods of detecting extrasolar planets are still in the development and beginning stages, only certain planets can be detected, if detected at all. As mentioned in the background about ...
... Before the conclusion, there is a specific bias in all of the results reached in this experiment: because current methods of detecting extrasolar planets are still in the development and beginning stages, only certain planets can be detected, if detected at all. As mentioned in the background about ...
mass loss of massive stars - of /proceedings
... Stars more massive than 25 M (et solar metallicity) end their lives as Wolf-Rayet stars (WR). The WR phase takes up to 5% of the star’s lifetime. Typically, a 40 M star will spend 0.2 Myr as a WR for a total lifetime of 5 Myr. During that phase, Wolf-Rayet stars have strong stellar winds character ...
... Stars more massive than 25 M (et solar metallicity) end their lives as Wolf-Rayet stars (WR). The WR phase takes up to 5% of the star’s lifetime. Typically, a 40 M star will spend 0.2 Myr as a WR for a total lifetime of 5 Myr. During that phase, Wolf-Rayet stars have strong stellar winds character ...
The kinematics of Galaxies in Compact Groups
... Two previous studies on the internal kinematics of compact group galaxies 1) Nishiura et al. (2000) studied 30 galaxies and found that most have peculiar rotation curves + dynamical properties of the galaxies do not correlate with any galaxy/group parameter. 2) Rubin et al. (1991) studied 32 galaxi ...
... Two previous studies on the internal kinematics of compact group galaxies 1) Nishiura et al. (2000) studied 30 galaxies and found that most have peculiar rotation curves + dynamical properties of the galaxies do not correlate with any galaxy/group parameter. 2) Rubin et al. (1991) studied 32 galaxi ...
Long Ago and Far Away
... allowing us to see faint infrared-emitting objects at the same level of detail that HST provides in visible light. 1.The galaxy (or merging pair) on page 1 with recession velocity 0.058 LY/yr is a rare example of a fairly nearby “ultraluminous infrared galaxy,” which is experiencing a starburst as i ...
... allowing us to see faint infrared-emitting objects at the same level of detail that HST provides in visible light. 1.The galaxy (or merging pair) on page 1 with recession velocity 0.058 LY/yr is a rare example of a fairly nearby “ultraluminous infrared galaxy,” which is experiencing a starburst as i ...
Oscillating White Dwarf Stars Background on White Dwarfs
... temperatures of 100.000.000 K. 8Be is unstable and decays back into He in 2.6 × 10–16 secs, but in the stellar interior a small equilibrium of 8Be exists. The 8Be ground state has almost exactly the energy of two alpha particles. In the second step, 8Be + 4He has almost exactly the energy of an exci ...
... temperatures of 100.000.000 K. 8Be is unstable and decays back into He in 2.6 × 10–16 secs, but in the stellar interior a small equilibrium of 8Be exists. The 8Be ground state has almost exactly the energy of two alpha particles. In the second step, 8Be + 4He has almost exactly the energy of an exci ...
Temperate Earth-sized planets transiting a nearby ultracool dwarf star
... with the radius of the planet. The background is colour-coded according to stellar mass (in units of the Sun’s mass). The TRAPPIST-1 planets are at the boundary between planets associated with hydrogen-burning stars and planets associated with brown dwarfs. Equilibrium temperatures are estimated neg ...
... with the radius of the planet. The background is colour-coded according to stellar mass (in units of the Sun’s mass). The TRAPPIST-1 planets are at the boundary between planets associated with hydrogen-burning stars and planets associated with brown dwarfs. Equilibrium temperatures are estimated neg ...
presentation source
... The existence of Dark matter was predicted in the 1930s by astronomer Fred Zwicky (who also predicted the existence of neutron stars) Zwicky had an eccentric ...
... The existence of Dark matter was predicted in the 1930s by astronomer Fred Zwicky (who also predicted the existence of neutron stars) Zwicky had an eccentric ...
Stellar population models in the Near-Infrared Meneses
... els, with slopes of −3.0 and −3.5) and a model that follows the IMF recipe of Chabrier with parameter χ = −1.3. The different initial mass function tests presented there give us insights into the complex star formation scenario that these early-type galaxies present. In future work, we will need to ...
... els, with slopes of −3.0 and −3.5) and a model that follows the IMF recipe of Chabrier with parameter χ = −1.3. The different initial mass function tests presented there give us insights into the complex star formation scenario that these early-type galaxies present. In future work, we will need to ...
Exploration of the Milky Way and Nearby galaxies
... Extremely metal-poor stars in the Milky Way and the Local group ...
... Extremely metal-poor stars in the Milky Way and the Local group ...
Terrestrial Planets
... material into dust grains distributed in a so-called debris disk. Because the grains have larger surface area per unit mass compared to larger bodies, they (re)radiate more energy and therefore are more easily detected in the infrared compared to their parent bodies. By studying this signal, we can ...
... material into dust grains distributed in a so-called debris disk. Because the grains have larger surface area per unit mass compared to larger bodies, they (re)radiate more energy and therefore are more easily detected in the infrared compared to their parent bodies. By studying this signal, we can ...
Stars - WhatisOutThere
... sky each night? The number of stars in the sky still remains a mystery to this day, because there are just too many to count. Stars are not spread out everywhere in space but are grouped together in galaxies. Instead of counting the stars individually, scientists look at the size and brightness of e ...
... sky each night? The number of stars in the sky still remains a mystery to this day, because there are just too many to count. Stars are not spread out everywhere in space but are grouped together in galaxies. Instead of counting the stars individually, scientists look at the size and brightness of e ...
Constellations and the Galactic Plane
... are all familiar names to northern hemisphere night sky watchers. There are 88 named constellations, each having numerous stars. This exercise takes you through some of the most recognizable ones in the October-November sky in the Bay Area. The patterns of stars remain the same over the ages. That i ...
... are all familiar names to northern hemisphere night sky watchers. There are 88 named constellations, each having numerous stars. This exercise takes you through some of the most recognizable ones in the October-November sky in the Bay Area. The patterns of stars remain the same over the ages. That i ...
After the ZAMS - Lincoln-Sudbury Regional High School
... Remember too about look-back time: the further away a star is, the longer its light takes to reach us. So our cameras may be receiving light (and therefore images) which left the star thousands of years ago. A 40 solar mass O5 star in the nearby galaxy Messier 31 will have evolved along the Main Seq ...
... Remember too about look-back time: the further away a star is, the longer its light takes to reach us. So our cameras may be receiving light (and therefore images) which left the star thousands of years ago. A 40 solar mass O5 star in the nearby galaxy Messier 31 will have evolved along the Main Seq ...
Galileo, Brahe, and Kepler - Pennsylvania State University
... JWST is a 6.5 m IR telescope that will be launched in 2014. Because of its large mirror, it will over much better sensitivity and spatial resolution than any previous IR telescope. It will focus on the first stars and galaxies, as well as planets around other stars. ...
... JWST is a 6.5 m IR telescope that will be launched in 2014. Because of its large mirror, it will over much better sensitivity and spatial resolution than any previous IR telescope. It will focus on the first stars and galaxies, as well as planets around other stars. ...
Introduction
... M (see, e.g. Halbwachs et al. 2003). There is a noticeable lack of brown dwarf companions orbiting close to their host star, which is commonly referred as the “brown dwarf desert”. This might point towards a different formation mechanism for the stellar and the planetary companions. • The eccentric ...
... M (see, e.g. Halbwachs et al. 2003). There is a noticeable lack of brown dwarf companions orbiting close to their host star, which is commonly referred as the “brown dwarf desert”. This might point towards a different formation mechanism for the stellar and the planetary companions. • The eccentric ...
Naval IQbservatory Washington 25. DC
... indicate that Sirius B has a mass of three quarters that of the sun and exhibits a red shift corresponding to 60 km/sec. or three times Adams' value which is now thought to be in error because of haste pranpted by the desire to confirm Einstein's theory as early as possible. Many astronomers have sp ...
... indicate that Sirius B has a mass of three quarters that of the sun and exhibits a red shift corresponding to 60 km/sec. or three times Adams' value which is now thought to be in error because of haste pranpted by the desire to confirm Einstein's theory as early as possible. Many astronomers have sp ...
Chapter 13 Other Planetary Systems: The New Science of Distant
... • We cannot measure an exact mass for a planet without knowing the tilt of its orbit, because Doppler shift tells us only the velocity toward or away from us. • Doppler data give us lower limits on masses. © 2010 Pearson Education, Inc. ...
... • We cannot measure an exact mass for a planet without knowing the tilt of its orbit, because Doppler shift tells us only the velocity toward or away from us. • Doppler data give us lower limits on masses. © 2010 Pearson Education, Inc. ...
Primary and secondary eclipse spectroscopy with JWST: exploring
... while indicating how the S /N scales with the fixed parameters. We systematically compare stellar photon noise-only plots with plots that include detailed instrumental and zodiacal noises. The likelihood of targets is based on both model and catalog star populations of the solar neighborhood. Result ...
... while indicating how the S /N scales with the fixed parameters. We systematically compare stellar photon noise-only plots with plots that include detailed instrumental and zodiacal noises. The likelihood of targets is based on both model and catalog star populations of the solar neighborhood. Result ...
Diffuse Ultraviolet Emission in Galaxies
... and B stars, which are typically few in number, but of overwhelming effect. The intense UV emission of these hot stars breaks molecules into atoms and ions, excites nebular emissions, and drives powerful winds, which can cut open and reshape the cloud. If O stars are present, they dominate events, p ...
... and B stars, which are typically few in number, but of overwhelming effect. The intense UV emission of these hot stars breaks molecules into atoms and ions, excites nebular emissions, and drives powerful winds, which can cut open and reshape the cloud. If O stars are present, they dominate events, p ...
Chemical Evolution
... • High abundances (1.7-2.5x solar) indicates that GCs formed rapidly before type Ia's contributed much to the gas (~1 Gyr) • However their remains puzzling patterns in how the different elemental abundances are correlated ...
... • High abundances (1.7-2.5x solar) indicates that GCs formed rapidly before type Ia's contributed much to the gas (~1 Gyr) • However their remains puzzling patterns in how the different elemental abundances are correlated ...
Planet-finding Activity Guide How do we find planets around other
... NASA and its partners also plan to use Gravitational Microlensing to find planets around other stars. This method derives from one of the insights of Einstein’s theory of general relativity: gravity bends space. We normally think of light as traveling in a straight line, but light rays become bent w ...
... NASA and its partners also plan to use Gravitational Microlensing to find planets around other stars. This method derives from one of the insights of Einstein’s theory of general relativity: gravity bends space. We normally think of light as traveling in a straight line, but light rays become bent w ...
Spiral galaxies: Spiral galaxies: Inclination Spiral galaxies: Internal
... absorption. Note that spin flips are classically “forbidden”: on average, a single hydrogen atom will take 107 years to decay! The probability of an absorption is even rarer. • HI gas mass is directly proportional to 21 cm line intensity • HI disk is much more extended than optical light, typically ...
... absorption. Note that spin flips are classically “forbidden”: on average, a single hydrogen atom will take 107 years to decay! The probability of an absorption is even rarer. • HI gas mass is directly proportional to 21 cm line intensity • HI disk is much more extended than optical light, typically ...
Space Interferometry Mission
The Space Interferometry Mission, or SIM, also known as SIM Lite (formerly known as SIM PlanetQuest), was a planned space telescope developed by the U.S. National Aeronautics and Space Administration (NASA), in conjunction with contractor Northrop Grumman. One of the main goals of the mission was the hunt for Earth-sized planets orbiting in the habitable zones of nearby stars other than the Sun. SIM was postponed several times and finally cancelled in 2010.In addition to hunting for extrasolar planets, SIM would have helped astronomers construct a map of the Milky Way galaxy. Other important tasks would have included collecting data to help pinpoint stellar masses for specific types of stars, assisting in the determination of the spatial distribution of dark matter in the Milky Way and in the Local Group of galaxies and using the gravitational microlensing effect to measure the mass of stars.The spacecraft would have used optical interferometry to accomplish these and other scientific goals. This technique collects light with multiple mirrors (in SIM's case, two) which is combined to make an interference pattern which can be very precisely measured.The initial contracts for SIM Lite were awarded in 1998, totaling US$200 million. Work on the SIM project required scientists and engineers to move through eight specific new technology milestones, and by November 2006, all eight had been completed.SIM Lite was originally scheduled for a 2005 launch, aboard an Evolved Expendable Launch Vehicle (EELV). As a result of continued budget cuts, the launch date has been pushed back at least five times. NASA has set a preliminary launch date for 2015 and U.S. federal budget documents confirm that a launch date is expected ""no earlier"" than 2015. The budget cuts to SIM Lite are expected to continue through FY 2010. As of February 2007, many of the engineers working on the SIM program had moved on to other areas and projects, and NASA directed the project to allocate its resources toward engineering risk reduction. However, the preliminary budget for NASA for 2008 included zero dollars for SIM.In December 2007, the Congress restored funding for fiscal year 2008 as part of an omnibus appropriations bill which the President later signed. At the same time the Congress directed NASA to move the mission forward to the development phase. In 2009 the project continued its risk reduction work while waiting for the findings and recommendations of the Astronomy and Astrophysics Decadal Survey, Astro2010, performed by the National Academy of Sciences, which would determine the project's future.On 13 August 2010, the Astro2010 Decadal Report was released and did not recommend that NASA continue the development of the SIM Lite Astrometric Observatory. This prompted NASA Astronomy and Physics Director, Jon Morse, to issue a letter on 24 September 2010 to the SIM Lite project manager, informing him that NASA was discontinuing its sponsorship of the SIM Lite mission and directing the project to discontinue Phase B activities immediately or as soon as practical. Accordingly, all SIM Lite activities were closed down by the end of calendar year 2010.