Searching for the oldest, most metal-poor stars in the SkyMapper Survey
... In the first minutes after the Big Bang, apart from traces of lithium, hydrogen and helium were the only elements that were present. Hydrogen consisted of ∼ 0.75 of the matter by mass fraction, helium was ∼ 0.25, and lithium was ∼ 2 × 10−9 . The first generation of stars, termed Population III stars ...
... In the first minutes after the Big Bang, apart from traces of lithium, hydrogen and helium were the only elements that were present. Hydrogen consisted of ∼ 0.75 of the matter by mass fraction, helium was ∼ 0.25, and lithium was ∼ 2 × 10−9 . The first generation of stars, termed Population III stars ...
A search for a new class of pulsating DA white dwarf stars in the DB
... The pulsating white dwarfs of most interest to us in the context of our survey for a new kind of pulsator in the DB gap are the third known type of pulsating white dwarf stars, the DBV, or V777 Her stars. For his PhD thesis work Winget (1982) theoretically predicted the existence of a class of heliu ...
... The pulsating white dwarfs of most interest to us in the context of our survey for a new kind of pulsator in the DB gap are the third known type of pulsating white dwarf stars, the DBV, or V777 Her stars. For his PhD thesis work Winget (1982) theoretically predicted the existence of a class of heliu ...
Night Sky Observations
... Astronomical Unit (A.U.): The average distance from the Earth to the Sun, approximately 150 million km. Light Year: The distance travelled by light in one year = 9 500 billion km (63,240 AU). Parsec: The distance at which a star would have a parallax of one arc second with a baseline of 1 AU (the me ...
... Astronomical Unit (A.U.): The average distance from the Earth to the Sun, approximately 150 million km. Light Year: The distance travelled by light in one year = 9 500 billion km (63,240 AU). Parsec: The distance at which a star would have a parallax of one arc second with a baseline of 1 AU (the me ...
Star Formation - Leslie Looney
... http://homepage.smc.edu/balm_simon/images/astro%205/spock.jpg ...
... http://homepage.smc.edu/balm_simon/images/astro%205/spock.jpg ...
Microsoft Word 97
... 3) Stars at different distances from the center of our galaxy revolve around the galaxy’s center in different lengths of time. 4) Stars closer to the center revolve much more quickly than does our Sun. a) Therefore the question arises: Why haven’t the spiral arms wound up very tightly? b) The leadin ...
... 3) Stars at different distances from the center of our galaxy revolve around the galaxy’s center in different lengths of time. 4) Stars closer to the center revolve much more quickly than does our Sun. a) Therefore the question arises: Why haven’t the spiral arms wound up very tightly? b) The leadin ...
the heavens revealed - Chapin Library
... Alfonso X “the Wise” of Leon and Castile. Their starting point is May , the eve of the king’s coronation. Based on Ptolemy’s nd-century Almagest with certain mathematical refinements, and following the general format of tables by the th-century Cordoban astronomer al-Zarqali, the Alfonsine ...
... Alfonso X “the Wise” of Leon and Castile. Their starting point is May , the eve of the king’s coronation. Based on Ptolemy’s nd-century Almagest with certain mathematical refinements, and following the general format of tables by the th-century Cordoban astronomer al-Zarqali, the Alfonsine ...
Chapter 15: The Milky Way Galaxy
... Earth’s location in the Milky Way how interstellar gas and dust enable star formation to continue in our Galaxy that observations reveal the presence of significant mass in the Milky Way that astronomers have yet to identify that there is a black hole at the center of our Galaxy ...
... Earth’s location in the Milky Way how interstellar gas and dust enable star formation to continue in our Galaxy that observations reveal the presence of significant mass in the Milky Way that astronomers have yet to identify that there is a black hole at the center of our Galaxy ...
... The temperature range over which the growth occurred is about 100 oC, so Meibom was able to calculate a cooling rate for the portion of the nebula in which the metal grains grew. By dividing the temperature interval (100 oC) by the growth time (19 days, or 456 hours), he found a cooling rate of 0.2 ...
X-ray binaries
... Donors can be WDs, or normal low-mass stars (main sequence or sub-giants). Many sources are found in globular clusters. Also there are more and more LMXBs found in more distant galaxies. In optics the emission is dominated by an accretion disc around a compact object. Clear classification is based o ...
... Donors can be WDs, or normal low-mass stars (main sequence or sub-giants). Many sources are found in globular clusters. Also there are more and more LMXBs found in more distant galaxies. In optics the emission is dominated by an accretion disc around a compact object. Clear classification is based o ...
X-ray binaries
... Donors can be WDs, or normal low-mass stars (main sequence or sub-giants). Many sources are found in globular clusters. Also there are more and more LMXBs found in more distant galaxies. In optics the emission is dominated by an accretion disc around a compact object. Clear classification is based o ...
... Donors can be WDs, or normal low-mass stars (main sequence or sub-giants). Many sources are found in globular clusters. Also there are more and more LMXBs found in more distant galaxies. In optics the emission is dominated by an accretion disc around a compact object. Clear classification is based o ...
University of Arizona Department of Astronomy
... Spaceships need rockets on at all times to keep moving I can’t see all of the Moon because the Earth is in the way The Big Bang organized pre-existing matter There is no air on the Moon so there cannot be gravity on the Moon All bright stars must be very hot The solar system contains millions of sta ...
... Spaceships need rockets on at all times to keep moving I can’t see all of the Moon because the Earth is in the way The Big Bang organized pre-existing matter There is no air on the Moon so there cannot be gravity on the Moon All bright stars must be very hot The solar system contains millions of sta ...
THE ABSOLUTE MAGNITUDE OF RR LYRAE - Cosmos
... stars with larger relative errors have brighter luminosities, i.e., have smaller parallaxes, appears clearly when the true parallax is small, compared with error of parallax. Similarly the distant stars have too faint luminosities, i.e., have too large parallaxes, mainly because the true parallax is ...
... stars with larger relative errors have brighter luminosities, i.e., have smaller parallaxes, appears clearly when the true parallax is small, compared with error of parallax. Similarly the distant stars have too faint luminosities, i.e., have too large parallaxes, mainly because the true parallax is ...
3.2 Black body Radiation
... By obtaining and analyzing the spectrum from a distant object, astronomers can identify what type of object it is and determine a wealth of characteristics for the object. These include its effective temperature, how fast it is rotating and whether it is moving towards or away from us, how large and ...
... By obtaining and analyzing the spectrum from a distant object, astronomers can identify what type of object it is and determine a wealth of characteristics for the object. These include its effective temperature, how fast it is rotating and whether it is moving towards or away from us, how large and ...
The barycentric motion of exoplanet host stars
... motion of the star about the system barycentre can be approximated by the linear superposition of the reflex motions due to the Keplerian orbit of each individual planet around that star-planet barycentre. If the planets have periods or close approaches such that they are dynamically interacting, th ...
... motion of the star about the system barycentre can be approximated by the linear superposition of the reflex motions due to the Keplerian orbit of each individual planet around that star-planet barycentre. If the planets have periods or close approaches such that they are dynamically interacting, th ...
The Hertzsprung-Russell Diagramm
... Stars of the same spectral class can have different luminosities. A further system, the M organKeenan (M -K) system, was introduced to make the distinction between the different luminosity classes (1943; Atlas of Stellar Spectra by W.W. M organ and P. C. Keenan). These luminosity classes range from ...
... Stars of the same spectral class can have different luminosities. A further system, the M organKeenan (M -K) system, was introduced to make the distinction between the different luminosity classes (1943; Atlas of Stellar Spectra by W.W. M organ and P. C. Keenan). These luminosity classes range from ...
Chapter 1 Introduction
... as a snapshot representing its present evolutionary stage, even throughout the entire life of an astronomer. However, by observing a number of young stars on different evolutionary stages, a chronological sequence can be pieced together. If young stars can be placed reliably in an evolutionary seque ...
... as a snapshot representing its present evolutionary stage, even throughout the entire life of an astronomer. However, by observing a number of young stars on different evolutionary stages, a chronological sequence can be pieced together. If young stars can be placed reliably in an evolutionary seque ...
September 3, 2013
... Its location is easy to find just inside the Great Square of Pegasus. But you'll need a moderately large telescope and a good sky; the cluster's brightest member, giant NGC 7768, appears 12th or 13th magnitude. If you succeed, could this be your record-farthest galaxy? The cluster is 300 million lig ...
... Its location is easy to find just inside the Great Square of Pegasus. But you'll need a moderately large telescope and a good sky; the cluster's brightest member, giant NGC 7768, appears 12th or 13th magnitude. If you succeed, could this be your record-farthest galaxy? The cluster is 300 million lig ...
Ursa Minor
Ursa Minor (Latin: ""Smaller She-Bear"", contrasting with Ursa Major), also known as the Little Bear, is a constellation in the northern sky. Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, hence the name Little Dipper. It was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Ursa Minor has traditionally been important for navigation, particularly by mariners, due to Polaris being the North Star.Polaris, the brightest star in the constellation, is a yellow-white supergiant and the brightest Cepheid variable star in the night sky, ranging from apparent magnitude 1.97 to 2.00. Beta Ursae Minoris, also known as Kochab, is an aging star that has swollen and cooled to become an orange giant with an apparent magnitude of 2.08, only slightly fainter than Polaris. Kochab and magnitude 3 Gamma Ursae Minoris have been called the ""guardians of the pole star"". Planets have been detected orbiting four of the stars, including Kochab. The constellation also contains an isolated neutron star—Calvera—and H1504+65, the hottest white dwarf yet discovered with a surface temperature of 200,000 K.