Full Text - Departement Natuurkunde en Sterrenkunde
... Strömgren photometric system . . . . . . . . . . . . . . . . . . . . . 165 ...
... Strömgren photometric system . . . . . . . . . . . . . . . . . . . . . 165 ...
The physics and modes of star cluster formation: observations
... phase of early stellar evolution. As many as 50 per cent of all members of a young cluster may have lost their discs and any other accretion signatures at an age of 2–3 Myr. Observations made from space with X-ray observatories, such as the Chandra X-ray Observatory, have shown that young stars emit ...
... phase of early stellar evolution. As many as 50 per cent of all members of a young cluster may have lost their discs and any other accretion signatures at an age of 2–3 Myr. Observations made from space with X-ray observatories, such as the Chandra X-ray Observatory, have shown that young stars emit ...
Core and conal component analysis of pulsar B1237 +25 Zuzana Srostlik,
... Fig. 3 gives an average profile for the quiet-normal-mode sequences. It represents the sum of those intervals exhibiting little or no core activity and in practice it differs indistinguishably from an average of the residuum after flare-normal and abnormal-mode intervals have been identified and rem ...
... Fig. 3 gives an average profile for the quiet-normal-mode sequences. It represents the sum of those intervals exhibiting little or no core activity and in practice it differs indistinguishably from an average of the residuum after flare-normal and abnormal-mode intervals have been identified and rem ...
Multiwavelength observations of XTE J1118+480`s outburst
... Different geometries, different possible scenarii ...
... Different geometries, different possible scenarii ...
Observations of Jets and Outflows from Young Stars
... into a jet, with a velocity several times the escape-speed from the launch region, which can range from 100 to over 500 km s−1 . Internal shocks form where faster ejecta overrun slower material. The very fastest shocks can sometimes be detected in X-rays. These primary flows often contain molecules ...
... into a jet, with a velocity several times the escape-speed from the launch region, which can range from 100 to over 500 km s−1 . Internal shocks form where faster ejecta overrun slower material. The very fastest shocks can sometimes be detected in X-rays. These primary flows often contain molecules ...
Building galaxies Hunt, Leslie Kipp
... “S0’s”, a class of galaxies roughly intermediate between ellipticals and early-type Sa spirals, but with a variety of appearances because of the presence or absence of dust lanes (Sandage 1961). They lack spiral arms but, unlike ellipticals, contain a low-surface brightness envelope surrounding the ...
... “S0’s”, a class of galaxies roughly intermediate between ellipticals and early-type Sa spirals, but with a variety of appearances because of the presence or absence of dust lanes (Sandage 1961). They lack spiral arms but, unlike ellipticals, contain a low-surface brightness envelope surrounding the ...
The chemical composition of solar-type stars and its impact on the
... period of time. One of these ideas is the trace a planet will leave in the composition of its host star: since both planet and host are formed from the same material and the composition of a planet can be very different from that of its host star, a planet host might look different in terms of eleme ...
... period of time. One of these ideas is the trace a planet will leave in the composition of its host star: since both planet and host are formed from the same material and the composition of a planet can be very different from that of its host star, a planet host might look different in terms of eleme ...
Astronomy Astrophysics - Niels Bohr Institutet
... of such ages has been obtained. Finally, we have computed individual Galactic orbits for all stars with adequate data. The resulting data set should place a wide range of studies of the evolution of the Galactic disk on a new and considerably improved footing. We caution, however, that no such thing ...
... of such ages has been obtained. Finally, we have computed individual Galactic orbits for all stars with adequate data. The resulting data set should place a wide range of studies of the evolution of the Galactic disk on a new and considerably improved footing. We caution, however, that no such thing ...
nexstar_gt_60,80114.. - Downloads
... the most sophisticated and easy to use telescopes available on the market today. Take time to read through this manual before embarking on your journey through the Universe. It may take a few observing sessions to become familiar with your NexStar, so you should keep this manual handy until you have ...
... the most sophisticated and easy to use telescopes available on the market today. Take time to read through this manual before embarking on your journey through the Universe. It may take a few observing sessions to become familiar with your NexStar, so you should keep this manual handy until you have ...
Multiplicity in Early Stellar Evolution - Astronomy Group
... with observations (see Fig. 1). Observations of molecular clouds have shown that magnetic fields are generally more dynamically important than turbulence, but are only one source of cloud support against gravitational collapse for cloud densities in the range of 103–104 cm−3 (Crutcher, 2012). While ...
... with observations (see Fig. 1). Observations of molecular clouds have shown that magnetic fields are generally more dynamically important than turbulence, but are only one source of cloud support against gravitational collapse for cloud densities in the range of 103–104 cm−3 (Crutcher, 2012). While ...
Formation of Molecular Clouds and Global Conditions for Star
... (Evans et al. 2009; Heiderman et al. 2010; Lada et al. 2010, 2012). These relations take on different shapes at different scales. Early studies of whole galaxies found a power-law correlation between total gas content (H I plus H2 ) and star formation rate (SFR) with an index N ∼ 1.5 (Kennicutt 1989 ...
... (Evans et al. 2009; Heiderman et al. 2010; Lada et al. 2010, 2012). These relations take on different shapes at different scales. Early studies of whole galaxies found a power-law correlation between total gas content (H I plus H2 ) and star formation rate (SFR) with an index N ∼ 1.5 (Kennicutt 1989 ...
Unraveling the Helix Nebula: Its Structure and Knots
... of material, surrounded by a lower ionization outer-ring that is almost perpendicular to the inner-disk. This interpretation is strengthened by its explanation of the complex radial velocity pattern described by radio and optical observations. There is an outer structure called the outermost-ring wh ...
... of material, surrounded by a lower ionization outer-ring that is almost perpendicular to the inner-disk. This interpretation is strengthened by its explanation of the complex radial velocity pattern described by radio and optical observations. There is an outer structure called the outermost-ring wh ...
Circumstellar dust emission from nearby Solar
... Far-infrared excess above the photosphere of a star indicates the presence of a circumstellar dust disc, which is a sign-post for extrasolar planets, and was first detected in the mid 1980s. Dust discs are intricately connected to planets and planetesimals, give insights in the dynamics and evolutio ...
... Far-infrared excess above the photosphere of a star indicates the presence of a circumstellar dust disc, which is a sign-post for extrasolar planets, and was first detected in the mid 1980s. Dust discs are intricately connected to planets and planetesimals, give insights in the dynamics and evolutio ...
Sample syllabus 2 - Johns Hopkins Center for Talented Youth
... Course Description: When the sun runs out of fuel, will it explode in a giant supernova or fade out into a white dwarf? Does every galaxy revolve around a super-massive black hole? Will the universe continue to expand, or will it eventually collapse back upon itself in a reversal of the Big Bang? As ...
... Course Description: When the sun runs out of fuel, will it explode in a giant supernova or fade out into a white dwarf? Does every galaxy revolve around a super-massive black hole? Will the universe continue to expand, or will it eventually collapse back upon itself in a reversal of the Big Bang? As ...
IXO as an observatory in the large telescopes era
... kind of depth over much larger areas. IXO's combination of huge collecting area and excellent spatial resolution over a large field of view fulfils this requirement (Fig. 1.3). These observations will have enormous constraining power. Current semi-analytic models of galaxy formation in the early Uni ...
... kind of depth over much larger areas. IXO's combination of huge collecting area and excellent spatial resolution over a large field of view fulfils this requirement (Fig. 1.3). These observations will have enormous constraining power. Current semi-analytic models of galaxy formation in the early Uni ...
SPIRAL STRUCTURE IN THE OUTER GALACTIC
... Accurate distances require identifying clear sequences along a broad range of magnitudes. To reduce field star contamination in the lower main sequence we restrict the analysis to stars within the cluster limits. The limits are determined by inspection of radial density profiles created from star co ...
... Accurate distances require identifying clear sequences along a broad range of magnitudes. To reduce field star contamination in the lower main sequence we restrict the analysis to stars within the cluster limits. The limits are determined by inspection of radial density profiles created from star co ...
Set 3 AStronomy questions
... X) the same surface temperatures Y) very similar chemical compositions Z) the same apparent magnitudes ANSWER: Y) VERY SIMILAR CHEMICAL COMPOSITIONS BONUS 7) ASTRONOMY Multiple Choice When binary stars are made of a main sequence star and a compact white dwarf, as long as the white dwarf’s mass rema ...
... X) the same surface temperatures Y) very similar chemical compositions Z) the same apparent magnitudes ANSWER: Y) VERY SIMILAR CHEMICAL COMPOSITIONS BONUS 7) ASTRONOMY Multiple Choice When binary stars are made of a main sequence star and a compact white dwarf, as long as the white dwarf’s mass rema ...
Analysis of Angular Momentum in Planetary Systems and Host Stars
... systems’ angular momenta, including both the planetary orbital and stellar spin components, are widely spread above and below the primary power law, but on average agree well with the primary relationship. The results indicate that the primary power law describes angular momenta of stars of <2 solar ...
... systems’ angular momenta, including both the planetary orbital and stellar spin components, are widely spread above and below the primary power law, but on average agree well with the primary relationship. The results indicate that the primary power law describes angular momenta of stars of <2 solar ...
Mid-IR Spectra of IRAS 20343+4129 IRS 1 and IRS 3 M.F. Campbell
... We interpret our low resolution spectra and photometry with simple models that have two emitting dust cloud components (each with constant temperature and density), and an overlying absorbing cloud component. The models fit the spectra and 24.8 m photometry and give estimates of the column densitie ...
... We interpret our low resolution spectra and photometry with simple models that have two emitting dust cloud components (each with constant temperature and density), and an overlying absorbing cloud component. The models fit the spectra and 24.8 m photometry and give estimates of the column densitie ...
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.