Cassiopeia Kelly Pearce
... Epsilon Cassiopeiae has a traditional name Segin and is blue-white in colour (Stars.Astro.Illinois.edu, Segin, 2010). It forms the outer most left point of the W and is the fifth brightest of all 5 stars. It is noticeably dimmer than the remaining stars but definitively forms the one of the outermo ...
... Epsilon Cassiopeiae has a traditional name Segin and is blue-white in colour (Stars.Astro.Illinois.edu, Segin, 2010). It forms the outer most left point of the W and is the fifth brightest of all 5 stars. It is noticeably dimmer than the remaining stars but definitively forms the one of the outermo ...
The empirical mass distribution of hot B subdwarfs
... binary population simulations that provide, e.g., theoretical mass distributions for the resulting sdB stars from the various formation channels. The expected mass distributions for CE and RLOF channels, including observational selection effects, peak around ∼0.46 M , while the merger channel leave ...
... binary population simulations that provide, e.g., theoretical mass distributions for the resulting sdB stars from the various formation channels. The expected mass distributions for CE and RLOF channels, including observational selection effects, peak around ∼0.46 M , while the merger channel leave ...
ASTRONOMY AND ASTROPHYSICS Barium abundances in cool
... of [Ba/Fe] with [Fe/H] at [Fe/H] < ; : . For the extremely metal-poor stars ([Fe/H] < ; : ) barium is underabundant relative to iron by ; : dex, and [Ba/Fe] grows with increasing metallicity and reaches a solar value at about [Fe/H] ; : . The second feature is the large scatter of the data. It is wi ...
... of [Ba/Fe] with [Fe/H] at [Fe/H] < ; : . For the extremely metal-poor stars ([Fe/H] < ; : ) barium is underabundant relative to iron by ; : dex, and [Ba/Fe] grows with increasing metallicity and reaches a solar value at about [Fe/H] ; : . The second feature is the large scatter of the data. It is wi ...
Astron 104 Laboratory #9 Cepheid Variable Stars
... Figure 1: How a Cepheid star changes brightness with time. function of time. Note that the vertical axis represents the apparent magnitude, which can be easily measured, not the absolute magnitude. Click anywhere on the plot to return to the view of the sky. To assist you in making accurate readings ...
... Figure 1: How a Cepheid star changes brightness with time. function of time. Note that the vertical axis represents the apparent magnitude, which can be easily measured, not the absolute magnitude. Click anywhere on the plot to return to the view of the sky. To assist you in making accurate readings ...
Neon and oxygen in low activity stars: towards a coronal unification
... to additionally increase jointly within allowed errors would provide a sufficient opacity increase. Several objections to this solution were raised, especially from solar observers. A reassessment of solar coronal data from the Solar Maximum Mission led to an upper limit of Ne/O = 0.18 ± 0.04 for acti ...
... to additionally increase jointly within allowed errors would provide a sufficient opacity increase. Several objections to this solution were raised, especially from solar observers. A reassessment of solar coronal data from the Solar Maximum Mission led to an upper limit of Ne/O = 0.18 ± 0.04 for acti ...
Early-type stars in the core of the young open cluster Westerlund 2
... cluster displays significant photometric variability above 1% at the 1-σ level. The twelve brightest O-type stars are found to have spectral types between O3 and O6.5, significantly earlier than previously thought. Conclusions. The distance of the early-type stars in Westerlund 2 is established to b ...
... cluster displays significant photometric variability above 1% at the 1-σ level. The twelve brightest O-type stars are found to have spectral types between O3 and O6.5, significantly earlier than previously thought. Conclusions. The distance of the early-type stars in Westerlund 2 is established to b ...
The accretion disk paradigm for young stars
... of today’s symposium because we have strong evidence that they are responsible for young star activity – had already been identified as such as early as in 1950. Unfortunately, as data started to accumulate, these promising physical findings were clouded by what appeared to be contradictory observatio ...
... of today’s symposium because we have strong evidence that they are responsible for young star activity – had already been identified as such as early as in 1950. Unfortunately, as data started to accumulate, these promising physical findings were clouded by what appeared to be contradictory observatio ...
Weakened magnetic braking as the origin of anomalously
... observed rotation rates has immediate implications for gyrochronology. The rotation periods of the middle-aged stars that have passed this Rossby threshold represent only lower limits on the age. The empirical calibrations must be modified, and the weakened relationship between period and age will r ...
... observed rotation rates has immediate implications for gyrochronology. The rotation periods of the middle-aged stars that have passed this Rossby threshold represent only lower limits on the age. The empirical calibrations must be modified, and the weakened relationship between period and age will r ...
15_Testbank
... 10) Suppose that you measure the parallax angle for a particular star to be 0.5 arcsecond. The distance to this star is A) 0.5 light-year. B) 0.5 parsec. C) 5 light-years. D) 5 parsecs. E) 2 parsecs. Answer: E 11) The most distant stars we can measure stellar parallax for are approximately A) 50 pa ...
... 10) Suppose that you measure the parallax angle for a particular star to be 0.5 arcsecond. The distance to this star is A) 0.5 light-year. B) 0.5 parsec. C) 5 light-years. D) 5 parsecs. E) 2 parsecs. Answer: E 11) The most distant stars we can measure stellar parallax for are approximately A) 50 pa ...
A Spectroscopic Survey of a Sample of Active M Dwarfs.
... and rotation velocities have been measured by fits to the Hα profiles. Radial velocities have been measured by cross correlation. Artificial broadening of an observed spectrum has produced a relationship between Hα FWHM and rotation speed, which we use to infer rotation speeds for the entire sample ...
... and rotation velocities have been measured by fits to the Hα profiles. Radial velocities have been measured by cross correlation. Artificial broadening of an observed spectrum has produced a relationship between Hα FWHM and rotation speed, which we use to infer rotation speeds for the entire sample ...
Astronomy Astrophysics Circumstellar emission in Be/X-ray binaries of the Magellanic
... to the one used by Fabregat & Torrejón (1998). Unfortunately, such stars do not seem to exist or are very scarce. Therefore we used stars in the Large Magellanic Cloud (LMC) whose distance and reddening are satisfactorily studied by independent methods. Furthermore, the LMC presents a population dis ...
... to the one used by Fabregat & Torrejón (1998). Unfortunately, such stars do not seem to exist or are very scarce. Therefore we used stars in the Large Magellanic Cloud (LMC) whose distance and reddening are satisfactorily studied by independent methods. Furthermore, the LMC presents a population dis ...
Properties of Wolf-Rayet Stars - Paul Crowther, University of Sheffield
... or via UV, optical or near-IR emission lines. Mass-loss rates (e.g. Leitherer et al. 1997) follow from radio continuum observations using relatively simple analytical relations, under the assumption of homogeneity and spherical symmetry (Wright & Barlow 1975). Determinations of radio WR mass-loss ra ...
... or via UV, optical or near-IR emission lines. Mass-loss rates (e.g. Leitherer et al. 1997) follow from radio continuum observations using relatively simple analytical relations, under the assumption of homogeneity and spherical symmetry (Wright & Barlow 1975). Determinations of radio WR mass-loss ra ...
Chapter 12: Stars and Galaxies
... human eye, analysis of starlight might yield different information. Table 4 lists and shows four major stars that make up the constellation of Orion. Even though the stars might look similar to your eye, they are all very different. What can you learn about these stars from their data? Recall that a ...
... human eye, analysis of starlight might yield different information. Table 4 lists and shows four major stars that make up the constellation of Orion. Even though the stars might look similar to your eye, they are all very different. What can you learn about these stars from their data? Recall that a ...
Ch. 16 - Astro1010
... Brightest stars were known to, and named by, the ancients (Procyon) In 1604, stars within a constellation were ranked in order of brightness, and labeled with Greek letters (Alpha Centauri) In the early 18th century, stars were numbered from west to east in a constellation (61 Cygni) As more and mor ...
... Brightest stars were known to, and named by, the ancients (Procyon) In 1604, stars within a constellation were ranked in order of brightness, and labeled with Greek letters (Alpha Centauri) In the early 18th century, stars were numbered from west to east in a constellation (61 Cygni) As more and mor ...
hr diagrams of star clusters
... the red giant region of the HR-diagram becomes more populated. This chronology of events is illustrated in the HR diagrams below, in Figure 4, and it is clear from the graphs that the length of the main sequence of a star cluster is a clear indication of its age. Astronomers can actually make rather ...
... the red giant region of the HR-diagram becomes more populated. This chronology of events is illustrated in the HR diagrams below, in Figure 4, and it is clear from the graphs that the length of the main sequence of a star cluster is a clear indication of its age. Astronomers can actually make rather ...
HR DIAGRAMS OF STAR CLUSTERS
... the red giant region of the HR-diagram becomes more populated. This chronology of events is illustrated in the HR diagrams below, in Figure 4, and it is clear from the graphs that the length of the main sequence of a star cluster is a clear indication of its age. Astronomers can actually make rather ...
... the red giant region of the HR-diagram becomes more populated. This chronology of events is illustrated in the HR diagrams below, in Figure 4, and it is clear from the graphs that the length of the main sequence of a star cluster is a clear indication of its age. Astronomers can actually make rather ...
THE PERIOD OF ROTATION OF THE SUN
... the red giant region of the HR-diagram becomes more populated. This chronology of events is illustrated in the HR diagrams below, in Figure 4, and it is clear from the graphs that the length of the main sequence of a star cluster is a clear indication of its age. Astronomers can actually make rather ...
... the red giant region of the HR-diagram becomes more populated. This chronology of events is illustrated in the HR diagrams below, in Figure 4, and it is clear from the graphs that the length of the main sequence of a star cluster is a clear indication of its age. Astronomers can actually make rather ...
Binarity in carbon-enhanced metal-poor stars
... studies with sufficient accuracy and cadence to carry out a conclusive quantitative study. For 43 per cent of the stars there is only one radial velocity measurement available, making it impossible to tell whether they are part of a binary system. Most other stars have less than five measurements pu ...
... studies with sufficient accuracy and cadence to carry out a conclusive quantitative study. For 43 per cent of the stars there is only one radial velocity measurement available, making it impossible to tell whether they are part of a binary system. Most other stars have less than five measurements pu ...
Chemical abundances and winds of massive stars in M31: a Btype
... standard manner, using the same methods as described in McCarthy et al. (1997). The most difficult task was removing the strong background Ha nebular emission from the stellar spectrum. In fact complete removal proved impossible, and we have left in the residual (negative) nebular Ha line in Figs 6 ...
... standard manner, using the same methods as described in McCarthy et al. (1997). The most difficult task was removing the strong background Ha nebular emission from the stellar spectrum. In fact complete removal proved impossible, and we have left in the residual (negative) nebular Ha line in Figs 6 ...
Spectral classification of O–M stars on the basis of UBV photometry
... In the process of spectral classification, about 60% of analyzed stars have been assigned to a single or two rather close estimates of spectra. In the last case an average value was adopted. Another 40% of stars have obtained two substantially different estimates of spectra. Double results of the cl ...
... In the process of spectral classification, about 60% of analyzed stars have been assigned to a single or two rather close estimates of spectra. In the last case an average value was adopted. Another 40% of stars have obtained two substantially different estimates of spectra. Double results of the cl ...
The first photometric analysis of the overcontact binary MQ UMa with
... binary systems are still unsolved problems in astrophysics. The most popular evolutionary scenario is that they are formed from initially detached systems via angular momentum loss (AML) by means of magnetic stellar wind (Vilhu 1982; Eggen & Iben 1989). Model calculations suggest that these binary s ...
... binary systems are still unsolved problems in astrophysics. The most popular evolutionary scenario is that they are formed from initially detached systems via angular momentum loss (AML) by means of magnetic stellar wind (Vilhu 1982; Eggen & Iben 1989). Model calculations suggest that these binary s ...
Downloadable Full Text
... The UFD Reticulum II (Ret II) was recently discovered with Dark Energy Survey data12,13 and confirmed to be one of the most metal-poor galaxies known14. On 1-4 Oct 2015, we obtained high-resolution spectra of the nine brightest member stars in Ret II (see Table 1, Extended Data Figure 1). The abunda ...
... The UFD Reticulum II (Ret II) was recently discovered with Dark Energy Survey data12,13 and confirmed to be one of the most metal-poor galaxies known14. On 1-4 Oct 2015, we obtained high-resolution spectra of the nine brightest member stars in Ret II (see Table 1, Extended Data Figure 1). The abunda ...
arXiv:astro-ph/0508448v1 22 Aug 2005
... over 50% of massive runaways have enhanced surface He abundances and high rotational velocities, suggesting that their parent systems experienced mass transfer and therefore are good candidates for supernova separation. It should be noted that rapid rotation and enhanced abundances are not in themse ...
... over 50% of massive runaways have enhanced surface He abundances and high rotational velocities, suggesting that their parent systems experienced mass transfer and therefore are good candidates for supernova separation. It should be noted that rapid rotation and enhanced abundances are not in themse ...
Astronomy Astrophysics
... The atmospheric parameters T eff and log g need to be known in order to compute synthetic Hα line profiles. Atmospheric parameters (T eff , log g) determined spectroscopically were preferred when available. Values for 12 stars were taken from Bergeron et al. (1995a) and one from Claver et al. (1998). ...
... The atmospheric parameters T eff and log g need to be known in order to compute synthetic Hα line profiles. Atmospheric parameters (T eff , log g) determined spectroscopically were preferred when available. Values for 12 stars were taken from Bergeron et al. (1995a) and one from Claver et al. (1998). ...
Star catalogue
A star catalogue, or star catalog, is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, and this article covers only some of the more frequently quoted ones. Star catalogues were compiled by many different ancient peoples, including the Babylonians, Greeks, Chinese, Persians, and Arabs. Most modern catalogues are available in electronic format and can be freely downloaded from NASA's Astronomical Data Center.Completeness and accuracy is described by the weakest apparent magnitude V (largest number) and the accuracy of the positions.