Chemical composition of B-type supergiants in the OB8, OB10
... with what we expect for a genuine single member of the OB8 association. The radial velocity for OB8-76 differs by some 70 kms−1 which could suggest the star is part of a binary system, or has a peculiar velocities within the OB association. Being part of a binary does not necessarily exclude using t ...
... with what we expect for a genuine single member of the OB8 association. The radial velocity for OB8-76 differs by some 70 kms−1 which could suggest the star is part of a binary system, or has a peculiar velocities within the OB association. Being part of a binary does not necessarily exclude using t ...
bode elert johann
... may well have got in contact with Halley before 1725, when Harris left for Vera Cruz to make astronomical observations. He returned in 1727, and the results of his expedition were presented to the Royal Society in a paper communicated by Halley. This connection might have brought him the authorship ...
... may well have got in contact with Halley before 1725, when Harris left for Vera Cruz to make astronomical observations. He returned in 1727, and the results of his expedition were presented to the Royal Society in a paper communicated by Halley. This connection might have brought him the authorship ...
The formation and destruction of molecular clouds and galactic star
... HI clouds to create molecular clouds. According to the standard picture of supernova-regulated ISM dynamics (e.g., McKee & Ostriker 1977), the typical timescale between consecutive compressions by supernova remnants is about 1 Myr. The total creation rate of expanding bubbles is greater than the occ ...
... HI clouds to create molecular clouds. According to the standard picture of supernova-regulated ISM dynamics (e.g., McKee & Ostriker 1977), the typical timescale between consecutive compressions by supernova remnants is about 1 Myr. The total creation rate of expanding bubbles is greater than the occ ...
Chemical composition of 90 F and G disk dwarfs
... The parallax is taken from the Hipparcos Satellite observations (ESA 1997). For most program stars, the relative error in the parallax is of the order of 5%. Only two stars in our sample have errors larger than 10%. From these accurate parallaxes, stellar distances and absolute magnitudes were obtai ...
... The parallax is taken from the Hipparcos Satellite observations (ESA 1997). For most program stars, the relative error in the parallax is of the order of 5%. Only two stars in our sample have errors larger than 10%. From these accurate parallaxes, stellar distances and absolute magnitudes were obtai ...
Phy Pre 08 - PembyPhysics
... Fission of nuclei heavier than hydrogen Fusion of helium nuclei Fission of nuclei heavier then helium ...
... Fission of nuclei heavier than hydrogen Fusion of helium nuclei Fission of nuclei heavier then helium ...
Astronomy 10
... basic `distance-measuring unit' in the solar system. Make sure that you understand what an astronomical unit is. Seeds gives some measurements using numbers, but it's most important for you to be able to understand it in words, in terms of the distance between the Earth and the Sun. What is the Sol ...
... basic `distance-measuring unit' in the solar system. Make sure that you understand what an astronomical unit is. Seeds gives some measurements using numbers, but it's most important for you to be able to understand it in words, in terms of the distance between the Earth and the Sun. What is the Sol ...
A Search for Extrasolar Planets Using Echoes Produced in Flare
... emitted from the star. An implicit assumption is that the pulse of light propagates in all directions equally and simultaneously; that the pulse radiates isotropically. For the observer on Earth the pulse follows two paths: one directly to the observer, the other to the nearby object where the pulse ...
... emitted from the star. An implicit assumption is that the pulse of light propagates in all directions equally and simultaneously; that the pulse radiates isotropically. For the observer on Earth the pulse follows two paths: one directly to the observer, the other to the nearby object where the pulse ...
Gemini - www.BahaiStudies.net
... α Gem (Castor): the second brightest in the constellation after Pollux. Castor is a sextuple star system 52 light-years from Earth, which appears as a magnitude 1.6 blue-white star to the unaided eye. Two spectroscopic binaries are visible at magnitudes 1.9 and 3.0 with a period of 470 years. A wide ...
... α Gem (Castor): the second brightest in the constellation after Pollux. Castor is a sextuple star system 52 light-years from Earth, which appears as a magnitude 1.6 blue-white star to the unaided eye. Two spectroscopic binaries are visible at magnitudes 1.9 and 3.0 with a period of 470 years. A wide ...
preprint, pdf version - LESIA
... as R = 18−19 in the UCAC2 (Second US Naval Observatory CCD Astrograph Catalog) frame covering the sky path of these objects. Methods. During 2007–2009, we carried out an observational program at the ESO2p2/WFI (2.2 m Max-Planck ESO telescope with the Wide Field Imager) instrument. The observations c ...
... as R = 18−19 in the UCAC2 (Second US Naval Observatory CCD Astrograph Catalog) frame covering the sky path of these objects. Methods. During 2007–2009, we carried out an observational program at the ESO2p2/WFI (2.2 m Max-Planck ESO telescope with the Wide Field Imager) instrument. The observations c ...
– 1 – 1. Emission Lines in Nearby Galaxies 1.1.
... ratio of their strengths will yields a measure of temperature. The key diagnostic lines used include 4363 Å of [OIII], but this line is often too weak to be observed. Note that these are all forbidden lines, which means they have low transition probabilities. When the 4363 Å line is too weak to be ...
... ratio of their strengths will yields a measure of temperature. The key diagnostic lines used include 4363 Å of [OIII], but this line is often too weak to be observed. Note that these are all forbidden lines, which means they have low transition probabilities. When the 4363 Å line is too weak to be ...
Quantitative constraints on starburst cycles in galaxies with stellar
... libraries contain models with burst fractions very close to zero, which are essentially identical to the models in the continuous library, so the new minimum χ2 is guaranteed to be equal to or smaller than the old one. If the new χ2min /Nd lies in the range 2.37-6.25, the probability that the model ...
... libraries contain models with burst fractions very close to zero, which are essentially identical to the models in the continuous library, so the new minimum χ2 is guaranteed to be equal to or smaller than the old one. If the new χ2min /Nd lies in the range 2.37-6.25, the probability that the model ...
Astro-tomography: CAT-scanning accretion in compact binaries
... Spikes at the accreting WD • Single density (ne= 3-4 1015 cm-3) Stark profiles describe the spike properties remarkably well • Kinematics and density conditions of the spike match a slowly rotating emission line region tied to the accreting white dwarf ...
... Spikes at the accreting WD • Single density (ne= 3-4 1015 cm-3) Stark profiles describe the spike properties remarkably well • Kinematics and density conditions of the spike match a slowly rotating emission line region tied to the accreting white dwarf ...
the evolution of planetary systems with time
... study the fate of the planets in light of mass loss from the dying Sun (Duncan & Lissauer 1998). Recent related work estimates an effective outer boundary rB to the Solar System (due to stellar mass loss) in the range rB = 103 − 104 AU, where orbiting bodies inside this scale remain safely bound (Ve ...
... study the fate of the planets in light of mass loss from the dying Sun (Duncan & Lissauer 1998). Recent related work estimates an effective outer boundary rB to the Solar System (due to stellar mass loss) in the range rB = 103 − 104 AU, where orbiting bodies inside this scale remain safely bound (Ve ...
Barium and europium abundances in cool dwarf stars and
... Ba abundance consist of 88% and 12%, respectively, according to Cameron (1982), 87% and 13% according to Käppeler et al. (1989), and 81% and 19% according to the most recent data of Arlandini et al. (1999). The solar europium mostly originated from the r-process: 91% according to Cameron (1982) and ...
... Ba abundance consist of 88% and 12%, respectively, according to Cameron (1982), 87% and 13% according to Käppeler et al. (1989), and 81% and 19% according to the most recent data of Arlandini et al. (1999). The solar europium mostly originated from the r-process: 91% according to Cameron (1982) and ...
Master thesis
... wind enriches the interstellar medium with metals. On the contrary, also heavier materials produced in the shell are transferred to the core. Within some thermal pulses, the star loses the whole H-shell. During the TP-AGB phase there is an immense outflow of material up to 10−4 M /yr over a duratio ...
... wind enriches the interstellar medium with metals. On the contrary, also heavier materials produced in the shell are transferred to the core. Within some thermal pulses, the star loses the whole H-shell. During the TP-AGB phase there is an immense outflow of material up to 10−4 M /yr over a duratio ...
ASTRONOMY AND ASTROPHYSICS Barium and europium
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
Astro Review - Parkway C-2
... ANS: a spherical shell around the solar system formed by comets with long orbital periods ANS: They burn up. ANS: the study of the properties of light that depend on wavelength ANS: convection ANS: 11 ANS: During nuclear fusion, four hydrogen nuclei combine to form one helium nucleus. ANS: temperatu ...
... ANS: a spherical shell around the solar system formed by comets with long orbital periods ANS: They burn up. ANS: the study of the properties of light that depend on wavelength ANS: convection ANS: 11 ANS: During nuclear fusion, four hydrogen nuclei combine to form one helium nucleus. ANS: temperatu ...
Rigorous treatment of barycentric stellar motion
... As described by Schlesinger (1917), a star’s movement through space causes secular changes not only in the position, but also in its proper motion, parallax, and radial velocity as observed from the Sun (or the SSB). These are purely geometric effects due to the changing distance and angle between th ...
... As described by Schlesinger (1917), a star’s movement through space causes secular changes not only in the position, but also in its proper motion, parallax, and radial velocity as observed from the Sun (or the SSB). These are purely geometric effects due to the changing distance and angle between th ...
Introduction_to_pulsar_astronomy
... No one knows what happened to the remnant of the star that exploded as SN 1987 A (Sanduleak –69 202). Was a neutron star formed? Should we be able to see it? Landau (1938) and Oppenheimer and Volkoff (1939) calculated the radius of these objects. They predicted radii of the order of 10 km! Such smal ...
... No one knows what happened to the remnant of the star that exploded as SN 1987 A (Sanduleak –69 202). Was a neutron star formed? Should we be able to see it? Landau (1938) and Oppenheimer and Volkoff (1939) calculated the radius of these objects. They predicted radii of the order of 10 km! Such smal ...
In Class Activity Manual - Department of Physics and Astronomy
... the groups encountered. This is your best chance to give immediate feedback. ❏ I aim for about one group activity per class, occasionally two. If you can arrange it, go for class periods longer than 50 minutes. I schedule my class for two 75-minute periods per week. That permits a group activity (sa ...
... the groups encountered. This is your best chance to give immediate feedback. ❏ I aim for about one group activity per class, occasionally two. If you can arrange it, go for class periods longer than 50 minutes. I schedule my class for two 75-minute periods per week. That permits a group activity (sa ...
IK Pegasi
IK Pegasi (or HR 8210) is a binary star system in the constellation Pegasus. It is just luminous enough to be seen with the unaided eye, at a distance of about 150 light years from the Solar System.The primary (IK Pegasi A) is an A-type main-sequence star that displays minor pulsations in luminosity. It is categorized as a Delta Scuti variable star and it has a periodic cycle of luminosity variation that repeats itself about 22.9 times per day. Its companion (IK Pegasi B) is a massive white dwarf—a star that has evolved past the main sequence and is no longer generating energy through nuclear fusion. They orbit each other every 21.7 days with an average separation of about 31 million kilometres, or 19 million miles, or 0.21 astronomical units (AU). This is smaller than the orbit of Mercury around the Sun.IK Pegasi B is the nearest known supernova progenitor candidate. When the primary begins to evolve into a red giant, it is expected to grow to a radius where the white dwarf can accrete matter from the expanded gaseous envelope. When the white dwarf approaches the Chandrasekhar limit of 1.44 solar masses (M☉), it may explode as a Type Ia supernova.