Stellar Evolution
... Sequence when there is no more hydrogen fuel in their cores The first few events are similar to those in lowermass stars First a hydrogen shell, Then a core burning helium to carbon, Surrounded by helium- and hydrogen-burning shells ...
... Sequence when there is no more hydrogen fuel in their cores The first few events are similar to those in lowermass stars First a hydrogen shell, Then a core burning helium to carbon, Surrounded by helium- and hydrogen-burning shells ...
A Search for New Solar-Type Post-T Tauri Stars in
... young stars have been identified in each of these regions based on various techniques including objective prism surveys for chromospherically active Hα and CaII emission-line sources, the IRAS survey for objects with substantial mid-infrared excess due to circumstellar dust, and the ROSAT survey for ...
... young stars have been identified in each of these regions based on various techniques including objective prism surveys for chromospherically active Hα and CaII emission-line sources, the IRAS survey for objects with substantial mid-infrared excess due to circumstellar dust, and the ROSAT survey for ...
Stellar Evolution – Cosmic Cycles of Formation and Destruction
... becomes depleted and the fusion of hydrogen nuclei to helium nuclei stops. The massluminosity relationship for main sequence stars is defined as: L/L (Sun) ~ [M/M (Sun)]4. All main sequence stars with a mass less than ~8 solar masses are sometimes referred to as dwarf stars, with the coolest, least ...
... becomes depleted and the fusion of hydrogen nuclei to helium nuclei stops. The massluminosity relationship for main sequence stars is defined as: L/L (Sun) ~ [M/M (Sun)]4. All main sequence stars with a mass less than ~8 solar masses are sometimes referred to as dwarf stars, with the coolest, least ...
THE HR DIAGRAM
... Figure 3 illustrates the full scale of an HR diagram. The x‐axis at the top utilizes both spectral class and temperature while at the bottom, the x‐axis uses the B‐V color index. The y‐axis on the left uses luminosity in solar units while absolute magnitudes are at right. This is a plot of 22,00 ...
... Figure 3 illustrates the full scale of an HR diagram. The x‐axis at the top utilizes both spectral class and temperature while at the bottom, the x‐axis uses the B‐V color index. The y‐axis on the left uses luminosity in solar units while absolute magnitudes are at right. This is a plot of 22,00 ...
Star Maps - Astronomy Outreach - The University of Texas at Austin
... There are two wheels: one with constellations, and the other with constellations and coordinate lines. Students will use the constellation wheel when they go outside. B. Using the Star Wheel or Planisphere Compare the star wheel to the star maps. Note what is different between them. Answer: The ...
... There are two wheels: one with constellations, and the other with constellations and coordinate lines. Students will use the constellation wheel when they go outside. B. Using the Star Wheel or Planisphere Compare the star wheel to the star maps. Note what is different between them. Answer: The ...
- Cosmotography
... wide-field images from the 8-meter Subaru telescope, which resolve the nebulosity into a stream of red giant branch stars, and confirm its physical association with NGC 4449. The properties of the stream imply a massive dwarf spheroidal progenitor, which after complete disruption will deposit an amo ...
... wide-field images from the 8-meter Subaru telescope, which resolve the nebulosity into a stream of red giant branch stars, and confirm its physical association with NGC 4449. The properties of the stream imply a massive dwarf spheroidal progenitor, which after complete disruption will deposit an amo ...
10 New Constellations
... Also known as Alpha Persei, Mirfak is located around 500 light years from Earth and is the brightest star in the constellation, it's a white supergiant with a diameter around 30 times larger than the sun. Algol Also known as Beta Persei, Algol is actually a three star system located around 90 light ...
... Also known as Alpha Persei, Mirfak is located around 500 light years from Earth and is the brightest star in the constellation, it's a white supergiant with a diameter around 30 times larger than the sun. Algol Also known as Beta Persei, Algol is actually a three star system located around 90 light ...
Killer Skies
... billion Kelvin. This pattern of core ignition and shell ignition continues with a series of heavier nuclei as fusion fuel. At higher temperatures than carbon fusion, nuclei of oxygen, neon, and magnesium fuse to make silicon and sulfur. At even higher temperatures, silicon can fuse to make iron. Thu ...
... billion Kelvin. This pattern of core ignition and shell ignition continues with a series of heavier nuclei as fusion fuel. At higher temperatures than carbon fusion, nuclei of oxygen, neon, and magnesium fuse to make silicon and sulfur. At even higher temperatures, silicon can fuse to make iron. Thu ...
Early Star-Forming Galaxies
... However, at the target distance (corresponding to the epoch 9 billion to 11 billion years ago), Herschel could only spot bright galaxies producing stars at a rate of 50 or more Sun-like stars a year. To analyze galaxies creating stars below this threshold, the astronomers added more than 18,000 sta ...
... However, at the target distance (corresponding to the epoch 9 billion to 11 billion years ago), Herschel could only spot bright galaxies producing stars at a rate of 50 or more Sun-like stars a year. To analyze galaxies creating stars below this threshold, the astronomers added more than 18,000 sta ...
Finnish Centre for Astronomy with ESO
... objects, 60% of which are strongly beamed AGN, leading to the remark that the most common type of sources in the γ-ray sky are AGN whose relativistic jet points towards the Earth (i.e. blazars). Blazar nuclei have been systematically found to be hosted by giant elliptical galaxies. The latter has se ...
... objects, 60% of which are strongly beamed AGN, leading to the remark that the most common type of sources in the γ-ray sky are AGN whose relativistic jet points towards the Earth (i.e. blazars). Blazar nuclei have been systematically found to be hosted by giant elliptical galaxies. The latter has se ...
Globular Clusters
... a much wider population, partially disrupted and spread out throughout the Galactic halo and far beyond. In this respect, it has been estimated that, within the next ten billion years or so, most of the present Galactic GCs could disappear. On the other hand, we know today that four clusters in Sagi ...
... a much wider population, partially disrupted and spread out throughout the Galactic halo and far beyond. In this respect, it has been estimated that, within the next ten billion years or so, most of the present Galactic GCs could disappear. On the other hand, we know today that four clusters in Sagi ...
X-ray binaries
... The latest large catalogue (Li et al. arXiv: 0707.0544) includes 187 galactic and Magellanic Clouds LMXBs with NSs and BHs as accreting components. 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 LMX ...
... The latest large catalogue (Li et al. arXiv: 0707.0544) includes 187 galactic and Magellanic Clouds LMXBs with NSs and BHs as accreting components. 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 LMX ...
Star Formation in the Local Milky Way
... 3. The Origin of Stellar Mass 3.1. The Stellar Initial Mass Function According to the theory of stellar structure and evolution, once formed the subsequent life history of a star is entirely predetermined by the only two parameters: the star’s initial mass and, to a lesser extent, its chemical compo ...
... 3. The Origin of Stellar Mass 3.1. The Stellar Initial Mass Function According to the theory of stellar structure and evolution, once formed the subsequent life history of a star is entirely predetermined by the only two parameters: the star’s initial mass and, to a lesser extent, its chemical compo ...
Lecture18
... • Stars come in many luminosities • If astronomers could tell what the luminosity of a star ...
... • Stars come in many luminosities • If astronomers could tell what the luminosity of a star ...
X-ray Binaries in Nearby Galaxies
... - some of the puzzles Are HMXBs connected to Super Star Clusters ? ...
... - some of the puzzles Are HMXBs connected to Super Star Clusters ? ...
Whiteq
... white dwarf. White dwarves themselves can be no more massive than 1.4 times the mass of the sun. However, it is believed that the progenitor star can be as much as 4 times as massive as the sun, because during the end of their nuclear fuel burning stage most stars eject a large portion of their mass ...
... white dwarf. White dwarves themselves can be no more massive than 1.4 times the mass of the sun. However, it is believed that the progenitor star can be as much as 4 times as massive as the sun, because during the end of their nuclear fuel burning stage most stars eject a large portion of their mass ...
PPT
... • Monitoring of hundreds of thousands of stars to 200 pc for 1MJ planets with P < 10 years: – complete census of all stellar types (P=2-9 years) – actual masses, not just lower limits (m sin i) – 20,000-30,000 planets expected to 150-200 pc ...
... • Monitoring of hundreds of thousands of stars to 200 pc for 1MJ planets with P < 10 years: – complete census of all stellar types (P=2-9 years) – actual masses, not just lower limits (m sin i) – 20,000-30,000 planets expected to 150-200 pc ...
![arXiv:1505.07406v1 [hep-ph] 27 May 2015](http://s1.studyres.com/store/data/007750137_1-1343a5635a0dda57ac4b2d01226e2ce5-300x300.png)
arXiv:1505.07406v1 [hep-ph] 27 May 2015
... Neutron stars are believed to have strong magnetic fields. The field strength BS at the surface is estimated to be ∼ 1012 G for pulsars and ∼ 1015 G for magnetar candidates, but we do not have any good knowledge of the configuration of magnetic fields inside the star. Recently, quasi-periodic oscill ...
... Neutron stars are believed to have strong magnetic fields. The field strength BS at the surface is estimated to be ∼ 1012 G for pulsars and ∼ 1015 G for magnetar candidates, but we do not have any good knowledge of the configuration of magnetic fields inside the star. Recently, quasi-periodic oscill ...
Galaxies - University of Iowa Astrophysics
... A) They all have the same distance. B) Their luminosity can be determined from their pulsation period. C) They all have the same luminosity. D) They all have the same radius. ...
... A) They all have the same distance. B) Their luminosity can be determined from their pulsation period. C) They all have the same luminosity. D) They all have the same radius. ...
Chapter 20
... • When fusion ceases in the core, it begins to collapse and heat. Hydrogen fusion starts in the shell surrounding the core. • The helium core begins to heat up; as long as the star is at least 0.25 solar masses, the helium will get hot enough that fusion (to carbon) will start. • As the core collaps ...
... • When fusion ceases in the core, it begins to collapse and heat. Hydrogen fusion starts in the shell surrounding the core. • The helium core begins to heat up; as long as the star is at least 0.25 solar masses, the helium will get hot enough that fusion (to carbon) will start. • As the core collaps ...
Sky Watcher - Boise Astronomical Society
... The moon passes over Saturn on the afternoon of the 7th. In Chile and Argentina, they actually see the moon cover Saturn in what astronomers call an occultation. In Idaho, we only see the moon and Saturn separated by an angular distance of 1.3 degrees, or less than three times the moon’s apparent di ...
... The moon passes over Saturn on the afternoon of the 7th. In Chile and Argentina, they actually see the moon cover Saturn in what astronomers call an occultation. In Idaho, we only see the moon and Saturn separated by an angular distance of 1.3 degrees, or less than three times the moon’s apparent di ...
A Tour of the Radio Universe
... This mosaic image is the sharpest wide-angle view ever obtained of M82. The galaxy is remarkable for its bright blue disk, webs of shredded clouds, and fiery-looking plumes of glowing hydrogen blasting out of its central regions. Throughout the galaxy's center, young stars are being born 10 times fa ...
... This mosaic image is the sharpest wide-angle view ever obtained of M82. The galaxy is remarkable for its bright blue disk, webs of shredded clouds, and fiery-looking plumes of glowing hydrogen blasting out of its central regions. Throughout the galaxy's center, young stars are being born 10 times fa ...
Lecture 10 Spectra of Stars and Binaries
... • Visible Hydrogen absorpZon lines come from the second excited state. • B Stars (15‐30,000 K): Most of H is ionized, so only very weak H lines. • A Stars (10,000 K): Ideal excitaZon condiZons, strongest H lines. ...
... • Visible Hydrogen absorpZon lines come from the second excited state. • B Stars (15‐30,000 K): Most of H is ionized, so only very weak H lines. • A Stars (10,000 K): Ideal excitaZon condiZons, strongest H lines. ...
Serpens
Serpens (""the Serpent"", Greek Ὄφις) is a constellation of the northern hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations defined by the International Astronomical Union. It is unique among the modern constellations in being split into two non-contiguous parts, Serpens Caput (Serpent's Head) to the west and Serpens Cauda (Serpent's Tail) to the east. Between these two halves lies the constellation of Ophiuchus, the ""Serpent-Bearer"". In figurative representations, the body of the serpent is represented as passing behind Ophiuchus between Mu Serpentis in Serpens Caput and Nu Serpentis in Serpens Cauda.The brightest star in Serpens is the red giant star Alpha Serpentis, or Unukalhai, in Serpens Caput, with an apparent magnitude of 2.63. Also located in Serpens Caput are the naked-eye globular cluster Messier 5 and the naked-eye variables R Serpentis and Tau4 Serpentis. Notable extragalactic objects include Seyfert's Sextet, one of the densest galaxy clusters known; Arp 220, the prototypical ultraluminous infrared galaxy; and Hoag's Object, the most famous of the very rare class of galaxies known as ring galaxies.Part of the Milky Way's galactic plane passes through Serpens Cauda, which is therefore rich in galactic deep-sky objects, such as the Eagle Nebula (IC 4703) and its associated star cluster Messier 16. The nebula measures 70 light-years by 50 light-years and contains the Pillars of Creation, three dust clouds that became famous for the image taken by the Hubble Space Telescope. Other striking objects include the Red Square Nebula, one of the few objects in astronomy to take on a square shape; and Westerhout 40, a massive nearby star-forming region consisting of a molecular cloud and an H II region.