PDF only - at www.arxiv.org.
... of the Magi, sending them to Judea. This class of answers is possible only because modern astronomers can know the details of the ancient skies with remarkable accuracy. That is, the positions and characteristics of the Sun, Moon, planets, comets, and meteor showers are confidently known to high acc ...
... of the Magi, sending them to Judea. This class of answers is possible only because modern astronomers can know the details of the ancient skies with remarkable accuracy. That is, the positions and characteristics of the Sun, Moon, planets, comets, and meteor showers are confidently known to high acc ...
Stellar Spectroscopy (GA 3.0) - National Optical Astronomy
... surface of the star, but most of what is known about stars is determined from the many spectral lines seen in their spectrum. A close inspection of a starʼs spectrum will reveal many absorption lines, and for some stars, emission lines as well. These spectral lines can be used to determine an incred ...
... surface of the star, but most of what is known about stars is determined from the many spectral lines seen in their spectrum. A close inspection of a starʼs spectrum will reveal many absorption lines, and for some stars, emission lines as well. These spectral lines can be used to determine an incred ...
The Next Great Exoplanet Hunt Please share
... all different beasts with different hunting strategies. TESS will pursue the strategy of scanning the entire sky in a systematic manner, concentrating on each sector of the sky for about 27 days. It will use four optical cameras, each with an unusually wide (24 by 24 degrees) field of view, to monit ...
... all different beasts with different hunting strategies. TESS will pursue the strategy of scanning the entire sky in a systematic manner, concentrating on each sector of the sky for about 27 days. It will use four optical cameras, each with an unusually wide (24 by 24 degrees) field of view, to monit ...
The Life of a Star
... This is the second structure equation, that of hydrostatic equilibrium. Together with the mass equation, these two mechanical equations allow already some simple estimates of stellar conditions. Replace the derivatives in the hydrostatic equation by di erences between center (Pc ) and surface (P0 ...
... This is the second structure equation, that of hydrostatic equilibrium. Together with the mass equation, these two mechanical equations allow already some simple estimates of stellar conditions. Replace the derivatives in the hydrostatic equation by di erences between center (Pc ) and surface (P0 ...
Millisecond Pulsar Binaries at Transition
... •Basically the same as PSR J1023+0038 •After the transition: • a P=1.69 ms pulsar is seen •X-rays are orbitally modulated •Gamma-ray flux has decreased by a factor of 2 ...
... •Basically the same as PSR J1023+0038 •After the transition: • a P=1.69 ms pulsar is seen •X-rays are orbitally modulated •Gamma-ray flux has decreased by a factor of 2 ...
Document
... So, whatever calendar one adopts should account for the Tropical year and not the Sidereal or otherwise, the seasons will start earlier by about 20 minutes each year. The value of a Mean Tropical Year = 365.256363004 - .014172604493 = 365.2421904 days. The tropical year actually changes over the cen ...
... So, whatever calendar one adopts should account for the Tropical year and not the Sidereal or otherwise, the seasons will start earlier by about 20 minutes each year. The value of a Mean Tropical Year = 365.256363004 - .014172604493 = 365.2421904 days. The tropical year actually changes over the cen ...
Absolute magnitudes and kinematics of barium
... with known orbits or with variable radial-velocity, there is no substantial difference between both groups. On the other hand, McWilliam (1990) analysed several stars from the Lü list (1991) and found no heavy-element overabundances, suggesting that the Lü compilation could be ”contaminated” with ...
... with known orbits or with variable radial-velocity, there is no substantial difference between both groups. On the other hand, McWilliam (1990) analysed several stars from the Lü list (1991) and found no heavy-element overabundances, suggesting that the Lü compilation could be ”contaminated” with ...
The Nature of the Stars
... o the unaided eye, the night sky is spangled with several thousand stars, each appearing as a bright pinpoint of light. With a pair of binoculars, you can see some 10,000 other, fainter stars; with a 15-cm (6-in.) telescope, the total rises to more than 2 million. Astronomers now know that there are ...
... o the unaided eye, the night sky is spangled with several thousand stars, each appearing as a bright pinpoint of light. With a pair of binoculars, you can see some 10,000 other, fainter stars; with a 15-cm (6-in.) telescope, the total rises to more than 2 million. Astronomers now know that there are ...
PDF only - at www.arxiv.org.
... studies on the wide double stars are also in progress. The importance of visual double stars to astronomy needs to be emphasized. A study of their orbit permits the calculation of the sum of the masses of the components if we also have the parallax of the system. The first stage of orbit computation ...
... studies on the wide double stars are also in progress. The importance of visual double stars to astronomy needs to be emphasized. A study of their orbit permits the calculation of the sum of the masses of the components if we also have the parallax of the system. The first stage of orbit computation ...
Processing of Star Catalog and Star Image
... star magnitude. Table 2.1 shows different star magnitudes and their corresponding total numbers of stars in Star Catalog SAO J2000. To meet the demand of star identification by star sensor method, stars brighter than (or whose Mv is less than) certain magnitude are selected from the standard catalog ...
... star magnitude. Table 2.1 shows different star magnitudes and their corresponding total numbers of stars in Star Catalog SAO J2000. To meet the demand of star identification by star sensor method, stars brighter than (or whose Mv is less than) certain magnitude are selected from the standard catalog ...
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. ...
2013. CCAT. All Rights Reserved.
... C.M. Bradford for the X-Spec study team We are developing X-Spec, a multi-object wide-band direct-detection spectrometer for CCAT. X-Spec is designed for rapid full-band (195-510 GHz), moderate resolution (R~700) spectral surveys of galaxies, measuring the bright atomic fine-structure and molecular ...
... C.M. Bradford for the X-Spec study team We are developing X-Spec, a multi-object wide-band direct-detection spectrometer for CCAT. X-Spec is designed for rapid full-band (195-510 GHz), moderate resolution (R~700) spectral surveys of galaxies, measuring the bright atomic fine-structure and molecular ...
Sky-High 2015 - Irish Astronomical Society
... We all know the Heavens don't revolve. It is the other way round, the Earth rotates on its axis. But it looks otherwise and it is easier to describe things as we see them for our immediate purpose. The fact that the Earth turns on its axis about every 24 hours causes the Sun to rise in the east and ...
... We all know the Heavens don't revolve. It is the other way round, the Earth rotates on its axis. But it looks otherwise and it is easier to describe things as we see them for our immediate purpose. The fact that the Earth turns on its axis about every 24 hours causes the Sun to rise in the east and ...
Chapter 17
... mass can have different compositions. Most important: Stars do not move along the main sequence! Once they reach it, they are in equilibrium, and do not move until their fuel begins to run ...
... mass can have different compositions. Most important: Stars do not move along the main sequence! Once they reach it, they are in equilibrium, and do not move until their fuel begins to run ...
How to Build an Astrolabe
... 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, ...
... 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, ...
Nebulae.The Lagoon and Dumbbell Nebulae
... a remnant of a dying star which is approximately 2 times smaller than the Sun. The star is hot and blue with temperature of 85000K (Most of these stars usually turn into red giants. They lose their mass by ejection of the outer gas layers. These layers expand in space, forming a temporary wrap aroun ...
... a remnant of a dying star which is approximately 2 times smaller than the Sun. The star is hot and blue with temperature of 85000K (Most of these stars usually turn into red giants. They lose their mass by ejection of the outer gas layers. These layers expand in space, forming a temporary wrap aroun ...
Word - Stefan`s Florilegium
... One problem with the simple clepsydra was that the rate of flow of the water from the hole depended on the height of the water above it. The higher the water the more pressure and therefore the faster the flow. This meant there was no simple way to measure the passage of time in relation to the volu ...
... One problem with the simple clepsydra was that the rate of flow of the water from the hole depended on the height of the water above it. The higher the water the more pressure and therefore the faster the flow. This meant there was no simple way to measure the passage of time in relation to the volu ...
1. The Birth of a Star
... Milky Way is a hazy band of whitish matter that looks a bit like a faint cloud in space. In your viewscreen, it is crossing the center of the screen and is where the highest concentration of stars exists. That white stuff is actually stars … billions of stars … clustered so close together that their ...
... Milky Way is a hazy band of whitish matter that looks a bit like a faint cloud in space. In your viewscreen, it is crossing the center of the screen and is where the highest concentration of stars exists. That white stuff is actually stars … billions of stars … clustered so close together that their ...
Direct Detection of Galactic Halo Dark Matter
... to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this “dark matter” may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the galaxy itself. We conducted a survey to find faint, cool ...
... to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this “dark matter” may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the galaxy itself. We conducted a survey to find faint, cool ...
PDF format
... True or False?: If the standard candles you are using are less luminous than you think they are, then the distances you determine from them will be too small. a) True, because they are less luminous, they are further away. b) False, because they are less luminous, they are closer than you think an ...
... True or False?: If the standard candles you are using are less luminous than you think they are, then the distances you determine from them will be too small. a) True, because they are less luminous, they are further away. b) False, because they are less luminous, they are closer than you think an ...
Betelgeuse: an unauthorized biography
... (i.e. main sequence) mass 15+2 –5 M, the 15 M corresponding (with mass loss rates from Schaller et al.) to about 13.7 M now. This mass, combined with a radius of 780, 700 or 640 R implies a surface gravity of log g = –0.20, –0.11 and –0.04 respectively, very much in line with the value 0.0 (with ...
... (i.e. main sequence) mass 15+2 –5 M, the 15 M corresponding (with mass loss rates from Schaller et al.) to about 13.7 M now. This mass, combined with a radius of 780, 700 or 640 R implies a surface gravity of log g = –0.20, –0.11 and –0.04 respectively, very much in line with the value 0.0 (with ...
Perseus (constellation)
Perseus, named after the Greek mythological hero Perseus, is a constellation in the northern sky. It was one of 48 listed by the 2nd-century astronomer Ptolemy and among the 88 modern constellations defined by the International Astronomical Union (IAU). It is located in the northern celestial hemisphere near several other constellations named after legends surrounding Perseus, including Andromeda to the west and Cassiopeia to the north. Perseus is also bordered by Aries and Taurus to the south, Auriga to the east, Camelopardalis to the north, and Triangulum to the west.The galactic plane of the Milky Way passes through Perseus but is mostly obscured by molecular clouds. The constellation's brightest star is the yellow-white supergiant Alpha Persei (also called Mirfak), which shines at magnitude 1.79. It and many of the surrounding stars are members of an open cluster known as the Alpha Persei Cluster. The best-known star, however, is Algol (Beta Persei), linked with ominous legends because of its variability, which is noticeable to the naked eye. Rather than being an intrinsically variable star, it is an eclipsing binary. Other notable star systems in Perseus include X Persei, a binary system containing a neutron star, and GK Persei, a nova that peaked at magnitude 0.2 in 1901. The Double Cluster, comprising two open clusters quite near each other in the sky, was known to the ancient Chinese. The constellation gives its name to the Perseus Cluster (Abell 426), a massive galaxy cluster located 250 million light-years from Earth. It hosts the radiant of the annual Perseids meteor shower—one of the most prominent meteor showers in the sky.