NGC 6231: a young open cluster under X-rays
... O-type stars display a limited dispersion around the canonical relation : within our sample, X-ray variability only seen for probable CWBs only identified mechanism that produces a significant deviation from the ‘canonical’ relation ...
... O-type stars display a limited dispersion around the canonical relation : within our sample, X-ray variability only seen for probable CWBs only identified mechanism that produces a significant deviation from the ‘canonical’ relation ...
Local Group Encyclopedia of Astronomy & Astrophysics eaa.iop.org Mario L Mateo
... Not long after EDWIN HUBBLE established that galaxies are ‘island universes’ similar to our home galaxy, the MILKY WAY, he realized that a few of these external galaxies are considerably closer to us than any others. In 1936 he first coined the term ‘Local Group’ in his famous book The Realm of the ...
... Not long after EDWIN HUBBLE established that galaxies are ‘island universes’ similar to our home galaxy, the MILKY WAY, he realized that a few of these external galaxies are considerably closer to us than any others. In 1936 he first coined the term ‘Local Group’ in his famous book The Realm of the ...
How to Build an Astrolabe
... are all at an equal distance from the earth, fixed on the inside of an enormous sphere that has the earth at its centre. By using this model, they can create the twodimensional representation of this celestial sphere seen on star charts and astrolabes, the starry equivalent of a map of the earth. Th ...
... are all at an equal distance from the earth, fixed on the inside of an enormous sphere that has the earth at its centre. By using this model, they can create the twodimensional representation of this celestial sphere seen on star charts and astrolabes, the starry equivalent of a map of the earth. Th ...
astro-ph/0301519 PDF
... We present a series of systematic abundance measurements for 25 hot DA white dwarfs in the temperature range ~20000-110000K, based on far-UV spectroscopy with STIS/GHRS on HST, IUE and FUSE. Using our latest heavy element blanketed non-LTE stellar atmosphere calculations we have addressed the heavy ...
... We present a series of systematic abundance measurements for 25 hot DA white dwarfs in the temperature range ~20000-110000K, based on far-UV spectroscopy with STIS/GHRS on HST, IUE and FUSE. Using our latest heavy element blanketed non-LTE stellar atmosphere calculations we have addressed the heavy ...
Chap2-RadialVelocity
... and the combination K=f(a,e,P,i). Two additional terms are usually taken into account: (1) the systemic velocity Υ describing the constant component of the radial velocity of the system’s centre of mass relative to the solar system barycentre and (2) a linear trend parameter d,which may accommodate ...
... and the combination K=f(a,e,P,i). Two additional terms are usually taken into account: (1) the systemic velocity Υ describing the constant component of the radial velocity of the system’s centre of mass relative to the solar system barycentre and (2) a linear trend parameter d,which may accommodate ...
Slide 1
... The Life of a Heavy Star • For heavy stars the first part of their life is the same as for lighter stars: after the hydrogen runs out, gravity crushes the core • What is different is that for heavy stars there is so much mass that gravity can continue to crush the core, and the temperature can rise ...
... The Life of a Heavy Star • For heavy stars the first part of their life is the same as for lighter stars: after the hydrogen runs out, gravity crushes the core • What is different is that for heavy stars there is so much mass that gravity can continue to crush the core, and the temperature can rise ...
Consistent metallicity scale for cool dwarfs and giants
... The dwarfs were observed during ESO program 70D0356 with UVES (Ultraviolet and Visual Echelle Spectrograph, Dekker et al. 2000) at the 8.2m Kueyen telescope of the VLT (Very Large Telescope) with and spectral resolution of R ∼ 60 000. For consistency, we used spectra acquired with the same instrumen ...
... The dwarfs were observed during ESO program 70D0356 with UVES (Ultraviolet and Visual Echelle Spectrograph, Dekker et al. 2000) at the 8.2m Kueyen telescope of the VLT (Very Large Telescope) with and spectral resolution of R ∼ 60 000. For consistency, we used spectra acquired with the same instrumen ...
Stars and Planets Credits and Acknowledgements
... • Stars are born in giant clouds of gas and dust. • Many more low mass (cool) stars are born than high mass (hot) stars. Lifetimes of Stars: In this activity, students return to the concept of a scale model to make a scale model of time rather than distance. The lifetimes of different masses of star ...
... • Stars are born in giant clouds of gas and dust. • Many more low mass (cool) stars are born than high mass (hot) stars. Lifetimes of Stars: In this activity, students return to the concept of a scale model to make a scale model of time rather than distance. The lifetimes of different masses of star ...
Stars: Stellar Evol & “death” Galaxies Astronomy 1 — Elementary Astronomy
... A. HDE 226868 was observed falling into Cygnus X-1 B. the light from HDE226868 illuminates Cygnus X-1 allowing it to be seen C. the orbit of HDE226868 allows the mass of Cygnus X-1 to be determined Astronomy 1 - Elementary Astronomy ...
... A. HDE 226868 was observed falling into Cygnus X-1 B. the light from HDE226868 illuminates Cygnus X-1 allowing it to be seen C. the orbit of HDE226868 allows the mass of Cygnus X-1 to be determined Astronomy 1 - Elementary Astronomy ...
Determination of the distance to the Andromeda Galaxy using variable stars U
... up similarities and differences between solar and stellar flares is to continuously broaden the ensemble of analyzed flares (solar and stellar as well), thus making an observational base of different types of flaring activities available for theoretical purposes. This is how solar flare observations c ...
... up similarities and differences between solar and stellar flares is to continuously broaden the ensemble of analyzed flares (solar and stellar as well), thus making an observational base of different types of flaring activities available for theoretical purposes. This is how solar flare observations c ...
1 The Hubble Story (10:56)
... intricate tendrils of gas and fiery lobes… Hubble was the first telescope to directly observe white dwarfs in globular star clusters. White dwarfs are stellar remnants and provide a ‘fossil’ record of their progenitor stars that shone so brightly they long ago exhausted their nuclear fuel. These mea ...
... intricate tendrils of gas and fiery lobes… Hubble was the first telescope to directly observe white dwarfs in globular star clusters. White dwarfs are stellar remnants and provide a ‘fossil’ record of their progenitor stars that shone so brightly they long ago exhausted their nuclear fuel. These mea ...
The Oort cloud as a remnant of the protosolar nebula
... idea of interstellar cloud comet origin has already been proposed by several authors (omitting the theories which have been rejected, e.g. that by Lyttleton (1948), we can mention for example: Hasegawa (1976), Khanna & Sharma (1983), Yabushita (1985) or Greenberg (1998)). A particular argument in fa ...
... idea of interstellar cloud comet origin has already been proposed by several authors (omitting the theories which have been rejected, e.g. that by Lyttleton (1948), we can mention for example: Hasegawa (1976), Khanna & Sharma (1983), Yabushita (1985) or Greenberg (1998)). A particular argument in fa ...
to - NexStar Resource Site
... prehistoric times. Up to 1977 Saturn was believed to be the only planet with a ring system. It was later discovered that all of the gas planets had ring systems, albeit faint, of their own. Saturn is about 9.5 AU from the Sun or over 900,000,000 million miles. Since 1979 it has been visited by the P ...
... prehistoric times. Up to 1977 Saturn was believed to be the only planet with a ring system. It was later discovered that all of the gas planets had ring systems, albeit faint, of their own. Saturn is about 9.5 AU from the Sun or over 900,000,000 million miles. Since 1979 it has been visited by the P ...
Neutral material around the B[e] supergiant star LHA 115
... [Oi] lines. This neutral material is most plausibly located within their dense, cool circumstellar disks, which are formed from the (probably non-spherically symmetric) wind material released by the star. Neither the formation mechanism nor the resulting structure and internal kinematics of these di ...
... [Oi] lines. This neutral material is most plausibly located within their dense, cool circumstellar disks, which are formed from the (probably non-spherically symmetric) wind material released by the star. Neither the formation mechanism nor the resulting structure and internal kinematics of these di ...
Astronomy and Astrophysics (ASTRO)
... line, interactive units with built-in exercises, hands-on (offline) activities, ...
... line, interactive units with built-in exercises, hands-on (offline) activities, ...
Science Quarter 3 Lessons
... the greater the change in motion. Generally, the more mass* an object has, the less influence a given force will have on its motion. If no forces act on an object, the object does not change its motion and moves at constant speed in a given direction. If an object is not moving and no force acts on ...
... the greater the change in motion. Generally, the more mass* an object has, the less influence a given force will have on its motion. If no forces act on an object, the object does not change its motion and moves at constant speed in a given direction. If an object is not moving and no force acts on ...
Astronomy and Astrophysics (ASTRO) Iowa State University – 2013-2014 1
... An entirely web-based course covering topics in observing the sky and navigation by the stars for students with little or no previous experience. The course combines material on common naked-eye phenomena, such as daily and seasonal variations in the sky, with information on how these helped navigat ...
... An entirely web-based course covering topics in observing the sky and navigation by the stars for students with little or no previous experience. The course combines material on common naked-eye phenomena, such as daily and seasonal variations in the sky, with information on how these helped navigat ...
2 The Concept of “Spectral Classes”
... becomes a group containing as few as one member. There were two general problems that prevented the IUE Object Class system from succeeding and thereby preventing archival data users from conveniently retrieving archival information on groups of stars with common properties. One was that owing to it ...
... becomes a group containing as few as one member. There were two general problems that prevented the IUE Object Class system from succeeding and thereby preventing archival data users from conveniently retrieving archival information on groups of stars with common properties. One was that owing to it ...
Stellar kinematics
Stellar kinematics is the study of the movement of stars without needing to understand how they acquired their motion. This differs from stellar dynamics, which takes into account gravitational effects. The motion of a star relative to the Sun can provide useful information about the origin and age of a star, as well as the structure and evolution of the surrounding part of the Milky Way.In astronomy, it is widely accepted that most stars are born within molecular clouds known as stellar nurseries. The stars formed within such a cloud compose open clusters containing dozens to thousands of members. These clusters dissociate over time. Stars that separate themselves from the cluster's core are designated as members of the cluster's stellar association. If the remnant later drifts through the Milky Way as a coherent assemblage, then it is termed a moving group.