Chemical abundances and winds of massive stars in M31: a Btype
... respectively) reflect the reddening from intervening Galactic material. This Milky Way extinction is similar to what we expect for OB 10-64. Using these two stars and OB 10-64, we derive a mean M31 extinction law, which confirms the lack of a 2175-Å feature in M31, similar to the Small Magellanic C ...
... respectively) reflect the reddening from intervening Galactic material. This Milky Way extinction is similar to what we expect for OB 10-64. Using these two stars and OB 10-64, we derive a mean M31 extinction law, which confirms the lack of a 2175-Å feature in M31, similar to the Small Magellanic C ...
Process of Science: PreMainSequence Stellar Life Tracks on the HR
... If you watch the position of the red dot on the HR diagram as the interactive figure plays, you will see that the dot is highest — meaning the object is most luminous— when it is a protostar and therefore does not yet have internal fusion. This fact can be a little surprising, but do not forget tha ...
... If you watch the position of the red dot on the HR diagram as the interactive figure plays, you will see that the dot is highest — meaning the object is most luminous— when it is a protostar and therefore does not yet have internal fusion. This fact can be a little surprising, but do not forget tha ...
Galaxy Notes File
... •Lots of young, blue stars and interstellar material •Smaller than most spirals and elliptical galaxies •Two major subtypes: •spiral-like but without defined arms, show bright knots with O,B stars •unsymmetrical with dust lanes and gas filaments, explosive ...
... •Lots of young, blue stars and interstellar material •Smaller than most spirals and elliptical galaxies •Two major subtypes: •spiral-like but without defined arms, show bright knots with O,B stars •unsymmetrical with dust lanes and gas filaments, explosive ...
Astronomy Astrophysics First detection of the field star overdensity in the Perseus... &
... suitable direction to undertake this study on Galactic structure and kinematics is towards the anticenter and the Perseus arm. First, this direction presents lower interstellar extinction than the direction pointing to the Galactic center. Second, although slightly depending on the pitch angle, this ...
... suitable direction to undertake this study on Galactic structure and kinematics is towards the anticenter and the Perseus arm. First, this direction presents lower interstellar extinction than the direction pointing to the Galactic center. Second, although slightly depending on the pitch angle, this ...
... In the RRL data base of GEOS (2012) one can find a list of 96 times of maxima and the corresponding O-C diagram built with the ephemerides 2419130.305+0.28779276 E is reproduced in Figure 4. Visual observations show a particularly large scatter at HJD ∼ 2443800 which may be due to their larger uncer ...
Rotation Periods of Wide Binaries in the Kepler Field
... Because most of the stars that satisfy the present criteria are relatively nearby, they should be expected to have low interstellar reddening. In any case, since the two components presumably lie at the same distance, the reddening would be expected to be the same, and so will not affect Figure 1. T ...
... Because most of the stars that satisfy the present criteria are relatively nearby, they should be expected to have low interstellar reddening. In any case, since the two components presumably lie at the same distance, the reddening would be expected to be the same, and so will not affect Figure 1. T ...
1. The Birth of a Star
... toward a faint colored cloud in space named “M42”. Notice that in the same info display, the distance from you to that cloud is listed as 1,177.7 ly. The “ly” stands for “Light Year”. It is not a time, but a distance. It is the distance a beam of light will travel through space in one year. 13. Ligh ...
... toward a faint colored cloud in space named “M42”. Notice that in the same info display, the distance from you to that cloud is listed as 1,177.7 ly. The “ly” stands for “Light Year”. It is not a time, but a distance. It is the distance a beam of light will travel through space in one year. 13. Ligh ...
It is now recognized that the vast majority of ellipticals are of
... the two interacting galaxies. Much of the diffuse glow is from multimillion degree gas. Many of the point-like sources in the x-ray image are due to black holes and neutron stars in binary star systems. Mid-IR light (right) is well-suited to studying star formation and tracing dust in spiral galaxie ...
... the two interacting galaxies. Much of the diffuse glow is from multimillion degree gas. Many of the point-like sources in the x-ray image are due to black holes and neutron stars in binary star systems. Mid-IR light (right) is well-suited to studying star formation and tracing dust in spiral galaxie ...
Part IV: Stars
... interior, photons can only travel a fraction of a millimeter before “colliding” with an electron and deflecting into a new direction. So photons bounce around at random and only slowly make their way out of the Sun. Mathematical models use the observed composition and mass of the Sun, along with the ...
... interior, photons can only travel a fraction of a millimeter before “colliding” with an electron and deflecting into a new direction. So photons bounce around at random and only slowly make their way out of the Sun. Mathematical models use the observed composition and mass of the Sun, along with the ...
Red supergiants around the obscured open cluster Stephenson 2
... Anderson et al. 2011), where tens of sources display radial velocities in the vLSR ≈ 90 − 105 km s−1 interval. This is generally interpreted as the tangent point of the Scutum-Crux arm. There is a secondary maximum towards l ∼ 24◦ , where many sources have vLSR ≈ 110 km s−1 , similar to the systemic ...
... Anderson et al. 2011), where tens of sources display radial velocities in the vLSR ≈ 90 − 105 km s−1 interval. This is generally interpreted as the tangent point of the Scutum-Crux arm. There is a secondary maximum towards l ∼ 24◦ , where many sources have vLSR ≈ 110 km s−1 , similar to the systemic ...
How to Build an Astrolabe
... Star and Constellation Guide Many stars have traditional names that have been used to describe them for thousands of years. Stars are today named officially according to order of brightness within each constellation. The brightest star in a constellation is named α (alpha, the first letter in the Gr ...
... Star and Constellation Guide Many stars have traditional names that have been used to describe them for thousands of years. Stars are today named officially according to order of brightness within each constellation. The brightest star in a constellation is named α (alpha, the first letter in the Gr ...
Colour-magnitude diagrams of the post
... presence of a blue HB is made more clear in Fig. 3c where essentially no blue MS contamination is seen, and stars in the locus of the blue HB are still seen. A quantitative check of the presence of an HB was carried out by counting stars in frames with different apertures around the cluster center. ...
... presence of a blue HB is made more clear in Fig. 3c where essentially no blue MS contamination is seen, and stars in the locus of the blue HB are still seen. A quantitative check of the presence of an HB was carried out by counting stars in frames with different apertures around the cluster center. ...
A Digital Spectral Classification Atlas
... The MK Spectral classification system was founded by W.W. Morgan and P.C. Keenan in the year 1943, with the publication of the first photographic spectral classification atlas, An Atlas of Stellar Spectra (Morgan, Keenan & Kelleman, 1943). Since that time, the MK system has been extensively revised ...
... The MK Spectral classification system was founded by W.W. Morgan and P.C. Keenan in the year 1943, with the publication of the first photographic spectral classification atlas, An Atlas of Stellar Spectra (Morgan, Keenan & Kelleman, 1943). Since that time, the MK system has been extensively revised ...
Comparing stars - The Open University
... Above and to the left of the red giants we come to the supergiants. These are larger, and thus more luminous than red giants of comparable temperature, but they also extend to higher temperatures, where they are larger and more luminous than main sequence stars of comparable temperature. Rigel A is ...
... Above and to the left of the red giants we come to the supergiants. These are larger, and thus more luminous than red giants of comparable temperature, but they also extend to higher temperatures, where they are larger and more luminous than main sequence stars of comparable temperature. Rigel A is ...
here - NASA/IPAC Extragalactic Database
... actual system is a bit more complicated than this; see, e.g., Sota et al. 2011.) The NIII emission behavior has finally been demonstrated to be dependent on stellar wind strengths, although nitrogen abundance also plays an important role (Rivero Gonzáez et al. 2011). Of course, a significant proble ...
... actual system is a bit more complicated than this; see, e.g., Sota et al. 2011.) The NIII emission behavior has finally been demonstrated to be dependent on stellar wind strengths, although nitrogen abundance also plays an important role (Rivero Gonzáez et al. 2011). Of course, a significant proble ...
Abundances and possible diffusion of elements in M 67 stars⋆
... Effective temperatures: in establishing the effective temperatures of the programme stars we have used the colours (V − Ks ) and (V − Ic ), as well as the wings of the Hα lines, as primary indicators. We preferred the use of colours and Hα-line profiles to the use of metal-lines of different excitation ...
... Effective temperatures: in establishing the effective temperatures of the programme stars we have used the colours (V − Ks ) and (V − Ic ), as well as the wings of the Hα lines, as primary indicators. We preferred the use of colours and Hα-line profiles to the use of metal-lines of different excitation ...
SciPoster_Jan2009
... complex is one of the most prominent areas of star formation for low to intermediate mass stars. Padgett et al. (2008) recently presented Spitzer/MIPS data over a 14.4 square degree map of the entire Ophiuchus molecular cloud, finding more than 300 YSO candidates. Could LDN 425 be part of this “exte ...
... complex is one of the most prominent areas of star formation for low to intermediate mass stars. Padgett et al. (2008) recently presented Spitzer/MIPS data over a 14.4 square degree map of the entire Ophiuchus molecular cloud, finding more than 300 YSO candidates. Could LDN 425 be part of this “exte ...
The ISO–SWS Spectrum of Planetary Nebula NGC 7027
... NGC 7027’s spectrum is extremely rich as can be seen in Fig. 2.1. The hydrogen and helium lines are abundant in the whole spectrum but specially in the range 2.4–5.5 µm. Ions with high stages of ionization are found (i.e. Fe VII, Na VII, Ar VI) in the nebula. Nine molecular hydrogen lines (H2 ) have ...
... NGC 7027’s spectrum is extremely rich as can be seen in Fig. 2.1. The hydrogen and helium lines are abundant in the whole spectrum but specially in the range 2.4–5.5 µm. Ions with high stages of ionization are found (i.e. Fe VII, Na VII, Ar VI) in the nebula. Nine molecular hydrogen lines (H2 ) have ...
Module1: Scale of the Universe
... Ask&your&students&to&discuss&some&possible&difBiculties&of&measuring&cosmic& distances&using¶llax.&Ensure&they&mention&the&following&points:& Parallax&shifts&are&always&small.&& Parallax&shift&is&even&smaller&than&the&apparent&size&of&the&star.&In&additional,& starlight&is&refracted&by&Earth's&a ...
... Ask&your&students&to&discuss&some&possible&difBiculties&of&measuring&cosmic& distances&using¶llax.&Ensure&they&mention&the&following&points:& Parallax&shifts&are&always&small.&& Parallax&shift&is&even&smaller&than&the&apparent&size&of&the&star.&In&additional,& starlight&is&refracted&by&Earth's&a ...
Corona Australis
Corona Australis /kɵˈroʊnə ɒˈstreɪlɨs/ or Corona Austrina /kɵˈroʊnə ɒˈstraɪnə/ is a constellation in the Southern Celestial Hemisphere. Its Latin name means ""southern crown"", and it is the southern counterpart of Corona Borealis, the northern crown. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax.Although fainter than its namesake, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australis contains one of the closest star-forming regions to our Solar System—a dusty dark nebula known as the Corona Australis Molecular Cloud, lying about 430 light years away. Within it are stars at the earliest stages of their lifespan. The variable stars R and TY Coronae Australis light up parts of the nebula, which varies in brightness accordingly.