2 Coordinate systems
... When viewed from the surface of the Earth the sky above forms a hemisphere, astronomical objects are seen to be projected onto this hemisphere. and their locations are convenient to describe their location with two angular coordinates in the same manner as latitude and longitude are decided on the s ...
... When viewed from the surface of the Earth the sky above forms a hemisphere, astronomical objects are seen to be projected onto this hemisphere. and their locations are convenient to describe their location with two angular coordinates in the same manner as latitude and longitude are decided on the s ...
Observational studies of stellar rotation
... et al. 1998). More recently, a similar approach based on the analysis of the rotational splitting of mixed pressure and gravity modes allowed Deheuvels et al. (2012) to probe the internal rotation profile of a low-mass giant evolving off the main sequence, thus revealing a rapidly rotating inner cor ...
... et al. 1998). More recently, a similar approach based on the analysis of the rotational splitting of mixed pressure and gravity modes allowed Deheuvels et al. (2012) to probe the internal rotation profile of a low-mass giant evolving off the main sequence, thus revealing a rapidly rotating inner cor ...
Star Clusters in Mergers
... which is ~ 30 % closer than our previous estimate (we believe unlikely since peculiar velocity would have to be ~ 500 km/s). ...
... which is ~ 30 % closer than our previous estimate (we believe unlikely since peculiar velocity would have to be ~ 500 km/s). ...
WFIRST-2.4: What Every Astronomer Should Know
... would be able to survey hundreds of nearby stars, enabling the characterization of dozens of known cool Jupiter-mass companions, the discovery and characterization of a similar number of cool Jupiter and Neptune companions, and the detection and characterization of debris disks in systems containin ...
... would be able to survey hundreds of nearby stars, enabling the characterization of dozens of known cool Jupiter-mass companions, the discovery and characterization of a similar number of cool Jupiter and Neptune companions, and the detection and characterization of debris disks in systems containin ...
Introduction - Arecibo Observatory
... determined the trigonometric parallax of several stars in the Orion BN/KL region. This has allowed them to derive the most accurate value so far ($414\pm 7$~pc) for the distance to this region, about an order of magnitude better than the previous value of 361$^{+168}_{-87}$~pc determined from the op ...
... determined the trigonometric parallax of several stars in the Orion BN/KL region. This has allowed them to derive the most accurate value so far ($414\pm 7$~pc) for the distance to this region, about an order of magnitude better than the previous value of 361$^{+168}_{-87}$~pc determined from the op ...
Planetplanet scattering alone cannot explain the freefloating planet
... process remains unchanged for all orbital phases. It is only the wind density changes for different orbital phases offering different optical depth to the emitted radiation. However, these estimations may change if (i) the stellar wind is focused or (ii) the absorption is due to SSA in the jet. In f ...
... process remains unchanged for all orbital phases. It is only the wind density changes for different orbital phases offering different optical depth to the emitted radiation. However, these estimations may change if (i) the stellar wind is focused or (ii) the absorption is due to SSA in the jet. In f ...
Adaptive Optics Nicholas Devaney GTC project, Instituto de
... • Use numerical simulations to determine the performance of a dual-conjugate system suitable for use on a 10m telescope on La Palma (e.g. the GTC). • Want to determine performance as a function of guide star configuration and DM2 conjugate altitude (DM1 will be conjugate to the pupil). • Use a 7-lay ...
... • Use numerical simulations to determine the performance of a dual-conjugate system suitable for use on a 10m telescope on La Palma (e.g. the GTC). • Want to determine performance as a function of guide star configuration and DM2 conjugate altitude (DM1 will be conjugate to the pupil). • Use a 7-lay ...
Astro110-01 Lecture 7 The Copernican Revolution
... Stellar parallax is the difference in direction of a celestial object as seen by an observer from two widely separated points. • The measurement of parallax is used directly to find the distance of the body from the Earth (geocentric parallax) and from the Sun (heliocentric parallax). • The two posi ...
... Stellar parallax is the difference in direction of a celestial object as seen by an observer from two widely separated points. • The measurement of parallax is used directly to find the distance of the body from the Earth (geocentric parallax) and from the Sun (heliocentric parallax). • The two posi ...
Document
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
The cosmic origin of fluorine and sulphur
... small white dwarf in the middle of the picture, and around it the elements the giant star has produced and expelled into its surroundings are clearly visible. In practice my result means that all the fluorine we come in contact with, including that in our toothpaste, likely has been formed like this ...
... small white dwarf in the middle of the picture, and around it the elements the giant star has produced and expelled into its surroundings are clearly visible. In practice my result means that all the fluorine we come in contact with, including that in our toothpaste, likely has been formed like this ...
Fulltext PDF - Indian Academy of Sciences
... The massive rock in the park seems to have been sitting there, not moving, for a long time. It may have been sitting there for decades, sturdy and unmoving to all appearances. But it is not all that stationary when we realize that, being part of this earth, it is spinning around with the planet, swi ...
... The massive rock in the park seems to have been sitting there, not moving, for a long time. It may have been sitting there for decades, sturdy and unmoving to all appearances. But it is not all that stationary when we realize that, being part of this earth, it is spinning around with the planet, swi ...
21 The first edition of Galileo Galilei`s Istoria e dimostrazioni intorno
... John Wilkins’s Discovery of a World in the Moone, or, a Discourse Tending to Prove that ‘tis Probable There May Be Another Habitable World in That Planet (London: Sparke and Forrest, 1638) Wilkins’ book is decidedly not a work of science fiction but a set of propositions—the first being that “the st ...
... John Wilkins’s Discovery of a World in the Moone, or, a Discourse Tending to Prove that ‘tis Probable There May Be Another Habitable World in That Planet (London: Sparke and Forrest, 1638) Wilkins’ book is decidedly not a work of science fiction but a set of propositions—the first being that “the st ...
Document
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
RApid Temporal Survey-RATS I: Overview and first results
... enough apertures for light curve extraction, thus maximizing the S/N ratio for the photometry. In practice, this was achieved by using the positions of a couple of bright (but not saturated) stars. After having determined (and applied) the shifts for individual images, we obtained quasi-differential ...
... enough apertures for light curve extraction, thus maximizing the S/N ratio for the photometry. In practice, this was achieved by using the positions of a couple of bright (but not saturated) stars. After having determined (and applied) the shifts for individual images, we obtained quasi-differential ...
12 Introduction to Cepheid Variable Stars Exercise
... were ordered by increasing period that the variable stars were also ordered by increasing brightness. Because both the Small Magellanic Cloud and the Large Magellanic Cloud are each a single galaxy nearby then the cepheid variables within each cloud are relatively the same distance from earth. It se ...
... were ordered by increasing period that the variable stars were also ordered by increasing brightness. Because both the Small Magellanic Cloud and the Large Magellanic Cloud are each a single galaxy nearby then the cepheid variables within each cloud are relatively the same distance from earth. It se ...
Habitability of super-Earth planets around main
... 4.58 Gyr, see Schröder & Smith (2008) (for a metallicity of Z = 0.018), and the Sun’s present-day effective temperature is identified as Teff = 5774 K. Masses below 0.5 M⊙, i.e. mostly M-type stars, have been omitted from our study. Their stellar evolution can be neglected; their luminosity and stell ...
... 4.58 Gyr, see Schröder & Smith (2008) (for a metallicity of Z = 0.018), and the Sun’s present-day effective temperature is identified as Teff = 5774 K. Masses below 0.5 M⊙, i.e. mostly M-type stars, have been omitted from our study. Their stellar evolution can be neglected; their luminosity and stell ...
The Chemical Composition of Carbon-Rich, Very Metal
... its lower-mass companion, which is now observed as a CH star (McClure & Woodsworth 1990). In this case a carbon-rich metal-deficient star should exhibit the chemical composition of AGB stars (i.e., evolved intermediate-mass stars) at the earliest times. One distinct feature of these stars is the enh ...
... its lower-mass companion, which is now observed as a CH star (McClure & Woodsworth 1990). In this case a carbon-rich metal-deficient star should exhibit the chemical composition of AGB stars (i.e., evolved intermediate-mass stars) at the earliest times. One distinct feature of these stars is the enh ...
Stars 3
... Nebula. These include wisp-like structures that move outward away from the pulsar at half the speed of light, as well as a mysterious “halo” which remains stationary, but grows brighter then fainter over time. Also seen are the effects of two polar jets that move out along the rotation axis of the p ...
... Nebula. These include wisp-like structures that move outward away from the pulsar at half the speed of light, as well as a mysterious “halo” which remains stationary, but grows brighter then fainter over time. Also seen are the effects of two polar jets that move out along the rotation axis of the p ...
spectral lines as distant measurement tools
... Stars to the right have red appearance, to the left they are blue. The stellar brightness is measured as “photographic magnitude”, an inverted logarithmic scale for the amount of light received from different stars if they were all placed at the same distance. The diagram is not filled randomly, but ...
... Stars to the right have red appearance, to the left they are blue. The stellar brightness is measured as “photographic magnitude”, an inverted logarithmic scale for the amount of light received from different stars if they were all placed at the same distance. The diagram is not filled randomly, but ...
Starbursts – from 30 Doradus to Lyman
... galaxies; and extreme or “psychopathic” starbursts, mostly found in distant systems. The evidence that, to first order, we can indeed scale star-formation physics across these ranges is, fortunately, good. This implies that we require only modest (rather than fundamental) adjustments to the star-for ...
... galaxies; and extreme or “psychopathic” starbursts, mostly found in distant systems. The evidence that, to first order, we can indeed scale star-formation physics across these ranges is, fortunately, good. This implies that we require only modest (rather than fundamental) adjustments to the star-for ...
Hipparcos
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial objects on the sky. This permitted the accurate determination of proper motions and parallaxes of stars, allowing a determination of their distance and tangential velocity. When combined with radial-velocity measurements from spectroscopy, this pinpointed all six quantities needed to determine the motion of stars. The resulting Hipparcos Catalogue, a high-precision catalogue of more than 118,200 stars, was published in 1997. The lower-precision Tycho Catalogue of more than a million stars was published at the same time, while the enhanced Tycho-2 Catalogue of 2.5 million stars was published in 2000. Hipparcos ' follow-up mission, Gaia, was launched in 2013.The word ""Hipparcos"" is an acronym for High precision parallax collecting satellite and also a reference to the ancient Greek astronomer Hipparchus of Nicaea, who is noted for applications of trigonometry to astronomy and his discovery of the precession of the equinoxes.