July - Antelope Valley Astronomy Club
... distance of 7,100 light years away in the constellation of Cassiopeia, a molecular gas cloud is actively forming stars, including the massive O-class star BD+60 2522, which itself is a magnitude +8.7 star despite its great distance and its presence in a dusty region of space. Shining with a temperat ...
... distance of 7,100 light years away in the constellation of Cassiopeia, a molecular gas cloud is actively forming stars, including the massive O-class star BD+60 2522, which itself is a magnitude +8.7 star despite its great distance and its presence in a dusty region of space. Shining with a temperat ...
Spectroscopic Variability of Supergiant Star HD14134, B3Ia
... Hα profile in the spectrum of the star HD14134 had the shape of an inverse P Cygni profile (Fig.1a). Another variability pattern, where Hα appears only in weak emission (13/02/2016). The Hα line was absent in the spectra of December 29-30, 2013 and of February 15, 2016, while two carbon lines CII (λ 6 ...
... Hα profile in the spectrum of the star HD14134 had the shape of an inverse P Cygni profile (Fig.1a). Another variability pattern, where Hα appears only in weak emission (13/02/2016). The Hα line was absent in the spectra of December 29-30, 2013 and of February 15, 2016, while two carbon lines CII (λ 6 ...
Spectroscopic Variability of Supergiant Star HD14134, B3Ia
... Hα profile in the spectrum of the star HD14134 had the shape of an inverse P Cygni profile (Fig.1a). Another variability pattern, where Hα appears only in weak emission (13/02/2016). The Hα line was absent in the spectra of December 29-30, 2013 and of February 15, 2016, while two carbon lines CII (λ 6 ...
... Hα profile in the spectrum of the star HD14134 had the shape of an inverse P Cygni profile (Fig.1a). Another variability pattern, where Hα appears only in weak emission (13/02/2016). The Hα line was absent in the spectra of December 29-30, 2013 and of February 15, 2016, while two carbon lines CII (λ 6 ...
Emergency Land Navigation
... this outer sphere as a celestial sphere. The stars are fixed upon the sphere in relation to each other and thus are called fixed stars. Out of the many stars found on the sphere, there are only 57 of them, which we consider are bright enough to help us in our navigation. Planets as a class move amon ...
... this outer sphere as a celestial sphere. The stars are fixed upon the sphere in relation to each other and thus are called fixed stars. Out of the many stars found on the sphere, there are only 57 of them, which we consider are bright enough to help us in our navigation. Planets as a class move amon ...
Discovery of extremely lead-rich subdwarfs: does heavy metal signal
... Németh et al. (2012) describe a group of He-sdOs with 0 < log y < 1 and Teff > 40 000 K. Most of our stars have −1 < log y < 0.5 and Teff ≤ 40 000 K; most do lie to the right of 38 000 K boundary shown in Németh et al. (2012, fig. 6), but in the sparsely populated region between the normal sdBs an ...
... Németh et al. (2012) describe a group of He-sdOs with 0 < log y < 1 and Teff > 40 000 K. Most of our stars have −1 < log y < 0.5 and Teff ≤ 40 000 K; most do lie to the right of 38 000 K boundary shown in Németh et al. (2012, fig. 6), but in the sparsely populated region between the normal sdBs an ...
Chemical abundances and winds of massive stars in M31: a B
... Numerous surveys have identified OB and WR stars beyond the Magellanic Clouds e.g. Massey et al. (1986); Moffat & Shara (1987), although little quantitative analysis has been carried out to date. The only detailed studies of WolfRayet stars beyond the Magellanic Clouds have been studies of late WN s ...
... Numerous surveys have identified OB and WR stars beyond the Magellanic Clouds e.g. Massey et al. (1986); Moffat & Shara (1987), although little quantitative analysis has been carried out to date. The only detailed studies of WolfRayet stars beyond the Magellanic Clouds have been studies of late WN s ...
The Norma cluster (ACO3627) – II. The near-infrared Ks
... seem to have a steeper bright end than those without cD galaxies. Often the brightest galaxy is excluded to obtain a better fit, particularly in cD clusters. The Schechter parameters have also been found to vary depending on the region sampled within the cluster, the size of the area and the limitin ...
... seem to have a steeper bright end than those without cD galaxies. Often the brightest galaxy is excluded to obtain a better fit, particularly in cD clusters. The Schechter parameters have also been found to vary depending on the region sampled within the cluster, the size of the area and the limitin ...
Red supergiants around the obscured open cluster Stephenson 2
... supergiants. Amongst these clusters, Stephenson 2, with a core grouping of 26 red supergiants, is a strong candidate to be the most massive cluster in the Galaxy. Aims. Stephenson 2 is located close to a region where a strong over-density of red supergiants had been found. We explore the actual clus ...
... supergiants. Amongst these clusters, Stephenson 2, with a core grouping of 26 red supergiants, is a strong candidate to be the most massive cluster in the Galaxy. Aims. Stephenson 2 is located close to a region where a strong over-density of red supergiants had been found. We explore the actual clus ...
Early-type stars in the core of the young open cluster Westerlund 2
... is dominated by strong and broad H Balmer lines. Weak absorption lines of He λλ 4388, 4471, Mg λ 4481 and Si λ 4552 are also seen. The He λ 4471/Mg λ 4481 intensity ratio indicates a spectral type B8-A0. The appearance of some weak metallic lines favours an A0 classification, whilst ...
... is dominated by strong and broad H Balmer lines. Weak absorption lines of He λλ 4388, 4471, Mg λ 4481 and Si λ 4552 are also seen. The He λ 4471/Mg λ 4481 intensity ratio indicates a spectral type B8-A0. The appearance of some weak metallic lines favours an A0 classification, whilst ...
Lecture 2 Astronomical Distances
... HST sees Cepheids to D = 10-20 Mpc. H0 x D = 70 x 15 ~ 1000 km/s. not really far enough galaxy pecular velocities ~500 km/s. galaxies falling toward Virgo cluster. ...
... HST sees Cepheids to D = 10-20 Mpc. H0 x D = 70 x 15 ~ 1000 km/s. not really far enough galaxy pecular velocities ~500 km/s. galaxies falling toward Virgo cluster. ...
Stellarium User Guide - Skolekonsulenterne.dk
... planetarium. It will calculate the positions of the Sun and Moon, planets and stars, and draw how the sky would look to an observer depending on their location and the time. It can also draw the constellations and simulate astronomical phenomena such as meteor showers, and solar or lunar eclipses. S ...
... planetarium. It will calculate the positions of the Sun and Moon, planets and stars, and draw how the sky would look to an observer depending on their location and the time. It can also draw the constellations and simulate astronomical phenomena such as meteor showers, and solar or lunar eclipses. S ...
Notes on Stars
... In most observations, the fluxes measured are not monochromatic but are integrated over a filter bandpass. Typical broad band filters have widths of several hundred to 2000Å. The magnitude for a filter x (Tx(ν) =transmission function) is then defined via: ...
... In most observations, the fluxes measured are not monochromatic but are integrated over a filter bandpass. Typical broad band filters have widths of several hundred to 2000Å. The magnitude for a filter x (Tx(ν) =transmission function) is then defined via: ...
Hot subdwarf stars-galactic orbits and distribution perpendicular to
... Hot subdwarfs are blue, horizontal-branch like stars, representing the late stages of evolution of stars having started with less than about 2.5 M⊙ on the main sequence. The hotter subdwarf B (sdB) stars form a well defined group. Their luminosity is of the order of 10 L⊙ and their surface temperatu ...
... Hot subdwarfs are blue, horizontal-branch like stars, representing the late stages of evolution of stars having started with less than about 2.5 M⊙ on the main sequence. The hotter subdwarf B (sdB) stars form a well defined group. Their luminosity is of the order of 10 L⊙ and their surface temperatu ...
Spectroscopy: Unlocking the Secrets of Star Light
... CD where the pits encoding the digital information act as a grating and disperse light into a colourful spectrum. ...
... CD where the pits encoding the digital information act as a grating and disperse light into a colourful spectrum. ...
Spectroscopy: Unlocking the Secrets of Star Light
... CD where the pits encoding the digital information act as a grating and disperse light into a colourful spectrum. ...
... CD where the pits encoding the digital information act as a grating and disperse light into a colourful spectrum. ...
Astronomy 250 - University of Victoria
... Example: Suppose you are trying to measure the brightness of a star. You observe the star ten times, measure the brightness in each image, and find the average brightness from those 10 observations. However, you notice that the brightness changes slightly in each image, which means that your average ...
... Example: Suppose you are trying to measure the brightness of a star. You observe the star ten times, measure the brightness in each image, and find the average brightness from those 10 observations. However, you notice that the brightness changes slightly in each image, which means that your average ...
Star Clusters - Caltech Astronomy
... diagrams of two clusters will in general have the same shape, but will be shifted in magnitude by an amount equal to the difference in distance modulus between the two. There may also be additional shifts in magnitude and color index resulting from interstellar absorption. The general procedure is t ...
... diagrams of two clusters will in general have the same shape, but will be shifted in magnitude by an amount equal to the difference in distance modulus between the two. There may also be additional shifts in magnitude and color index resulting from interstellar absorption. The general procedure is t ...
The Classification of Stellar Spectra
... Background: The History And Nature Of Spectral Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the sp ...
... Background: The History And Nature Of Spectral Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the sp ...
Evolution of stars
... d. stronger. e. b and c The most common stars are a. supergiants. b. giants. c. upper main sequence stars. d. white dwarfs. e. lower main sequence stars. The __________ of a star is a measure of the total energy radiated by the star in one second. a. absolute visual magnitude b. apparent visual magn ...
... d. stronger. e. b and c The most common stars are a. supergiants. b. giants. c. upper main sequence stars. d. white dwarfs. e. lower main sequence stars. The __________ of a star is a measure of the total energy radiated by the star in one second. a. absolute visual magnitude b. apparent visual magn ...
Boötes
Boötes /boʊˈoʊtiːz/ is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning herdsman or plowman (literally, ox-driver; from βοῦς bous “cow”). The ""ö"" in the name is a diaeresis, not an umlaut, meaning that each 'o' is to be pronounced separately.One of the 48 constellations described by the 2nd century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth brightest star in the night sky, the orange-hued Arcturus. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye.