THE HELIACAL RISE OF SIRIUS- Algorithm
... In the course of the last 5 years of observations in Seattle, in the period 2001-2005 I have seen that one and the same star does appear on the same date, provided it is brighter than +1.5 mag.. In comparison I have observed how stars around +3.0 mag. appeared, in 2005, 3 days later than they did in ...
... In the course of the last 5 years of observations in Seattle, in the period 2001-2005 I have seen that one and the same star does appear on the same date, provided it is brighter than +1.5 mag.. In comparison I have observed how stars around +3.0 mag. appeared, in 2005, 3 days later than they did in ...
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 ...
Stars & Galaxies - newmanlib.ibri.org
... that they differ in brightness. • As one looks at the stars more carefully, it becomes apparent that they are not all the same color. • Look at the constellation of Orion shown in the next panel. ...
... that they differ in brightness. • As one looks at the stars more carefully, it becomes apparent that they are not all the same color. • Look at the constellation of Orion shown in the next panel. ...
Do We Know of Any Maunder Minimum Stars?
... log RHK < −5.1, the latter of which they considered Maunder minimum candidates. Baliunas & Jastrow (1990) suggested that the activity level of the sun during the Maunder Minimum corresponded to that of these low-activity stars, S = 0.1451. Zhang et al. (1994) applied this value to an analysis of the ...
... log RHK < −5.1, the latter of which they considered Maunder minimum candidates. Baliunas & Jastrow (1990) suggested that the activity level of the sun during the Maunder Minimum corresponded to that of these low-activity stars, S = 0.1451. Zhang et al. (1994) applied this value to an analysis of the ...
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... line in C-stars is strong, that of the TiO molecule in oxygen-rich stars of the same effective temperature is even more severe. The lower limit of Li abundance that can be measured is thus higher for O-rich stars than for C-rich stars. In both cases, a Li abundance determination can only be achieved ...
... line in C-stars is strong, that of the TiO molecule in oxygen-rich stars of the same effective temperature is even more severe. The lower limit of Li abundance that can be measured is thus higher for O-rich stars than for C-rich stars. In both cases, a Li abundance determination can only be achieved ...
here - NASA/IPAC Extragalactic Database
... plays an important role (Rivero Gonzáez et al. 2011). Of course, a significant problem occurs when one looks at O stars in other galaxies that are more metal-poor than the Milky Way where the various spectral standards have been defined. Even a high-luminosity O star in the SMC may fail to show He ...
... plays an important role (Rivero Gonzáez et al. 2011). Of course, a significant problem occurs when one looks at O stars in other galaxies that are more metal-poor than the Milky Way where the various spectral standards have been defined. Even a high-luminosity O star in the SMC may fail to show He ...
Evolution of stars
... 1. The hydrogen lines in spectral type A stars a. are most narrow for supergiants. b. are most narrow for main sequence stars. c. can not be used to estimate the luminosity of the star. d. are very weak and difficult to see. e. are useful in determining the apparent magnitude of the star. 2. Paralla ...
... 1. The hydrogen lines in spectral type A stars a. are most narrow for supergiants. b. are most narrow for main sequence stars. c. can not be used to estimate the luminosity of the star. d. are very weak and difficult to see. e. are useful in determining the apparent magnitude of the star. 2. Paralla ...
12-1 - Piscataway High School
... one with another and decide which was emitting more light and which less. Of course, the stars are scattered at different distances, and you can’t shove them around to line them up for comparison. If, however, you know the distance to a star, you can use the inverse square relation to calculate the ...
... one with another and decide which was emitting more light and which less. Of course, the stars are scattered at different distances, and you can’t shove them around to line them up for comparison. If, however, you know the distance to a star, you can use the inverse square relation to calculate the ...
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 ...
A Digital Spectral Classification Atlas
... When the MK system was first defined, it was based on photographic spectra in the blue-violet part of the spectrum. This was done by necessity, as scientific photographic emulsions in the 1940’s were sensitive only to blue-violet light. However, it was a fortunate choice, as the blue-violet portion ...
... When the MK system was first defined, it was based on photographic spectra in the blue-violet part of the spectrum. This was done by necessity, as scientific photographic emulsions in the 1940’s were sensitive only to blue-violet light. However, it was a fortunate choice, as the blue-violet portion ...
The 2008 RBSE Journal - National Optical Astronomy Observatory
... DRAGNs are found in starburst galaxies, which produce radio emission lines and are mainly formed in galaxies that are larger than their host galaxies, such as elliptical galaxies.(4) They are comprised of lobes, jets, and a core just as other radio galaxies are, and they also have hot spots in the l ...
... DRAGNs are found in starburst galaxies, which produce radio emission lines and are mainly formed in galaxies that are larger than their host galaxies, such as elliptical galaxies.(4) They are comprised of lobes, jets, and a core just as other radio galaxies are, and they also have hot spots in the l ...
preprint, pdf version - LESIA
... events observed in Brazil and Chile (4 June 2011) and in Hawaii (23 June 2011). These last two events, as in 22 June 2008, were double events in which Charon and Pluto occulted the same star. In the 4 June 2011 event in particular, both occultations could be recorded at each site. The population of ...
... events observed in Brazil and Chile (4 June 2011) and in Hawaii (23 June 2011). These last two events, as in 22 June 2008, were double events in which Charon and Pluto occulted the same star. In the 4 June 2011 event in particular, both occultations could be recorded at each site. The population of ...
Stellarium User Guide - Skolekonsulenterne.dk
... also notice that the stars have started to move slightly across the sky. If it’s daytime you might be able to see the sun moving (but it’s less apparent than the movement of the stars). Increase the rate at which time passes again by clicking on the button a third time. Now time is really flying! Le ...
... also notice that the stars have started to move slightly across the sky. If it’s daytime you might be able to see the sun moving (but it’s less apparent than the movement of the stars). Increase the rate at which time passes again by clicking on the button a third time. Now time is really flying! Le ...
Rotation Periods and Relative Ages of Solar-Type Stars
... context of previously-published hypotheses, calculated rotation periods, or Pcalc, were obtained for each star. These Pcalc are a function of chromospheric activity level as well as B - V spectral type. The formula for the calculation of rotation periods was derived from Noyes’ algorithm for determi ...
... context of previously-published hypotheses, calculated rotation periods, or Pcalc, were obtained for each star. These Pcalc are a function of chromospheric activity level as well as B - V spectral type. The formula for the calculation of rotation periods was derived from Noyes’ algorithm for determi ...
Astronomy Astrophysics Circumstellar emission in Be/X-ray binaries of the Magellanic
... Methods. Simultaneous U BVRI photometry and spectra in the 3500−7000 Å spectral range were obtained for 11 optical counterparts to Be/X-ray binaries in the LMC, 5 in the SMC and 12 in the Milky Way. As a measure of the amount of circumstellar emission we used the Hα equivalent width corrected for ph ...
... Methods. Simultaneous U BVRI photometry and spectra in the 3500−7000 Å spectral range were obtained for 11 optical counterparts to Be/X-ray binaries in the LMC, 5 in the SMC and 12 in the Milky Way. As a measure of the amount of circumstellar emission we used the Hα equivalent width corrected for ph ...
Published in Contemp. Phys. 51, 464-465 (2010).
... Sirius would have passed right across the Milky Way during the stone age. One of the Arabic names for Sirius is al-schira al-abur, or “Sirius which has passed across”, raising the fascinating speculation that there could somehow be a human memory of this ancient astronomical event. Sirius also wiggl ...
... Sirius would have passed right across the Milky Way during the stone age. One of the Arabic names for Sirius is al-schira al-abur, or “Sirius which has passed across”, raising the fascinating speculation that there could somehow be a human memory of this ancient astronomical event. Sirius also wiggl ...
Sample pages 1 PDF
... especially nearby, a mere 1,300 light years away. It is visible even to the naked eye, as a fuzzy patch halfway down the Sword of Orion asterism. A small telescope reveals its two brightest regions, the larger of which is M42 (NGC 1976) and the other M43 (NGC 1982). The Orion Molecular Cloud Complex ...
... especially nearby, a mere 1,300 light years away. It is visible even to the naked eye, as a fuzzy patch halfway down the Sword of Orion asterism. A small telescope reveals its two brightest regions, the larger of which is M42 (NGC 1976) and the other M43 (NGC 1982). The Orion Molecular Cloud Complex ...
Chapter 12
... seems to move against the background even though in reality it is your head that has changed position, not your hand. This simple demonstration illustrates how parallax gives a clue to an object’s distance. If you hold your hand at different distances from your face, you will notice that the apparen ...
... seems to move against the background even though in reality it is your head that has changed position, not your hand. This simple demonstration illustrates how parallax gives a clue to an object’s distance. If you hold your hand at different distances from your face, you will notice that the apparen ...
Long-term monitoring of the short period SU UMa
... We report on time-resolved CCD photometry of four outbursts of a short-period SU UMa-type dwarf nova, V844 Herculis. We successfully determined the mean superhump periods to be 0.05584(64) days, and 0.055883(3) for the 2002 May superoutburst, and the 2006 April-May superoutburst, respectively. Durin ...
... We report on time-resolved CCD photometry of four outbursts of a short-period SU UMa-type dwarf nova, V844 Herculis. We successfully determined the mean superhump periods to be 0.05584(64) days, and 0.055883(3) for the 2002 May superoutburst, and the 2006 April-May superoutburst, respectively. Durin ...
Notable long-period eclipsing binaries. Part I. - Project VS
... Unfortunately, the most recent eclipse was in January 2013, so the next one is really far away. The variability of AZ Cas was discovered by Beljawski (1931), while the period was determined 25 years later, by Ashbrook in 1956 (see Tempesti, 1979; AASS, 39, 115). In 1947 C. Hoffmeister classified the ...
... Unfortunately, the most recent eclipse was in January 2013, so the next one is really far away. The variability of AZ Cas was discovered by Beljawski (1931), while the period was determined 25 years later, by Ashbrook in 1956 (see Tempesti, 1979; AASS, 39, 115). In 1947 C. Hoffmeister classified the ...
Lithium abundances along the red giant branch: FLAMES
... agreed with the expected value for the difference in heliocentric correction, and the same shift was found for all spectra obtained at a given time. Therefore, we can exclude that these shifts are the result of orbital motion in a binary system. No other velocity shifts were found within the accuracy ...
... agreed with the expected value for the difference in heliocentric correction, and the same shift was found for all spectra obtained at a given time. Therefore, we can exclude that these shifts are the result of orbital motion in a binary system. No other velocity shifts were found within the accuracy ...
View the sky`s greatest nebula
... energy (from nearby stars). The atoms can’t hold the energy for long, however, and quickly release it as light. The Orion Nebula is a hotbed of star formation. The stars in and near the Trapezium are young — possibly only 300,000 years old. Theta1 (θ1) C Orionis contains 40 times the Sun’s mass and ...
... energy (from nearby stars). The atoms can’t hold the energy for long, however, and quickly release it as light. The Orion Nebula is a hotbed of star formation. The stars in and near the Trapezium are young — possibly only 300,000 years old. Theta1 (θ1) C Orionis contains 40 times the Sun’s mass and ...
Canis Minor
Canis Minor /ˌkeɪnɨs ˈmaɪnər/ is a small constellation in the northern celestial hemisphere. In the second century, it was included as an asterism, or pattern, of two stars in Ptolemy's 48 constellations, and it is counted among the 88 modern constellations. Its name is Latin for ""lesser dog"", in contrast to Canis Major, the ""greater dog""; both figures are commonly represented as following the constellation of Orion the hunter.Canis Minor contains only two stars brighter than the fourth magnitude, Procyon (Alpha Canis Minoris), with a magnitude of 0.34, and Gomeisa (Beta Canis Minoris), with a magnitude of 2.9. The constellation's dimmer stars were noted by Johann Bayer, who named eight stars including Alpha and Beta, and John Flamsteed, who numbered fourteen. Procyon is the seventh-brightest star in the night sky, as well as one of the closest. A yellow-white main sequence star, it has a white dwarf companion. Gomeisa is a blue-white main sequence star. Luyten's Star is a ninth-magnitude red dwarf and the Solar System's next closest stellar neighbour in the constellation after Procyon. The fourth-magnitude HD 66141, which has evolved into an orange giant towards the end of its life cycle, was discovered to have a planet in 2012. There are two faint deep sky objects within the constellation's borders. The 11 Canis-Minorids are a meteor shower that can be seen in early December.