Astronomy 250 - University of Victoria
... Every measured quantity will always have an associated uncertainy. Errors can occur, for example, because of the limitations of the measuring device, because of systematic offsets (see below), because of legitimate dispersions in the data, etc. Example: Suppose you are trying to measure the brightne ...
... Every measured quantity will always have an associated uncertainy. Errors can occur, for example, because of the limitations of the measuring device, because of systematic offsets (see below), because of legitimate dispersions in the data, etc. Example: Suppose you are trying to measure the brightne ...
Strong linear polarization of V4332 Sagittarii: a dusty disc geometry⋆
... Hügel 69, 53121 Bonn, Germany. ...
... Hügel 69, 53121 Bonn, Germany. ...
The Physics of Star Formation: Understanding the Youngest Protostars
... an evolutionary sequence from highly embedded protostars still accreting mass (Class I SED) to young stars surrounded by substantial accretion disks (Class II SED) to revealed young stars which have dissipated their disks and may have completed their planet formation (Class III SED). Although we hav ...
... an evolutionary sequence from highly embedded protostars still accreting mass (Class I SED) to young stars surrounded by substantial accretion disks (Class II SED) to revealed young stars which have dissipated their disks and may have completed their planet formation (Class III SED). Although we hav ...
... that happen to have a prominent disk around them [and] ellipticals as bulges that for some reason have missed the opportunity to acquire or maintain a prominent disk.” We adopt this point of view. However, as observations improve, we discover more and more features that make it difficult to interpre ...
Unlocking the secrets of stellar haloes using combined star counts
... by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright stars only account for a fraction of the overall halo light, which means that the star counts must be calibrated on to a surface brightn ...
... by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright stars only account for a fraction of the overall halo light, which means that the star counts must be calibrated on to a surface brightn ...
An approach to ground based space surveillance
... On Orbit Servicing (OOS) is a class of dual-use robotic space missions that could potentially extend the life of orbiting satellites by fuel replenishment, repair, inspection, orbital maintenance or satellite repurposing, and possibly reduce the rate of space debris generation. OOS performed in geos ...
... On Orbit Servicing (OOS) is a class of dual-use robotic space missions that could potentially extend the life of orbiting satellites by fuel replenishment, repair, inspection, orbital maintenance or satellite repurposing, and possibly reduce the rate of space debris generation. OOS performed in geos ...
ASTRO-114--Lecture 47-
... And so it was a way of detecting where all the hydrogen clouds are in the galaxy. You didn’t even have to see them. You just had to point your radio telescope around the sky and pick up all the 21 centimeter radiation that was coming to us. Now, what does it sound like? It’s static. It’s radio stati ...
... And so it was a way of detecting where all the hydrogen clouds are in the galaxy. You didn’t even have to see them. You just had to point your radio telescope around the sky and pick up all the 21 centimeter radiation that was coming to us. Now, what does it sound like? It’s static. It’s radio stati ...
A History of Astronomy, Astrophysics and Cosmology
... How did the Ptolemaic system of the World work? The sphere of the ‘fixed stars’ rotates about the Earth once per day. Against that pattern of stars, the Sun and Moon move in roughly circular paths about the Earth. In addition, the motions of the five planets observable to the naked eye-Mercury, Venu ...
... How did the Ptolemaic system of the World work? The sphere of the ‘fixed stars’ rotates about the Earth once per day. Against that pattern of stars, the Sun and Moon move in roughly circular paths about the Earth. In addition, the motions of the five planets observable to the naked eye-Mercury, Venu ...
Astrometry of Asteroids
... contains only 3522 stars, all of them rather bright. The right ascension and declination of the stars in the FK5 Catalog have been especially carefully measured and re-measured so that they can be relied upon as standard reference points for the measurement of the positions of other objects in the s ...
... contains only 3522 stars, all of them rather bright. The right ascension and declination of the stars in the FK5 Catalog have been especially carefully measured and re-measured so that they can be relied upon as standard reference points for the measurement of the positions of other objects in the s ...
Astrometry of Asteroids
... contains only 3522 stars, all of them rather bright. The right ascension and declination of the stars in the FK5 Catalog have been especially carefully measured and re-measured so that they can be relied upon as standard reference points for the measurement of the positions of other objects in the s ...
... contains only 3522 stars, all of them rather bright. The right ascension and declination of the stars in the FK5 Catalog have been especially carefully measured and re-measured so that they can be relied upon as standard reference points for the measurement of the positions of other objects in the s ...
NICMOS Coronagraphic Observations of 55 Cancri
... Near the star the NICMOS measurements are dominated by the residual systematic error in nulling out the imperfectly matched PSFs. While the 1-σ pixel-to-pixel noise in spatial regions far from the influence of circumferential diffracted and instrumentally scattered light is typically ∼0.2 µJy arcsec ...
... Near the star the NICMOS measurements are dominated by the residual systematic error in nulling out the imperfectly matched PSFs. While the 1-σ pixel-to-pixel noise in spatial regions far from the influence of circumferential diffracted and instrumentally scattered light is typically ∼0.2 µJy arcsec ...
Internal structure of a cold dark molecular cloud inferred
... inferred for the Loop I superbubble from X-ray observations with the ROSAT satellite13. The close correspondence of the observed extinction pro®le with that predicted for a Bonnor±Ebert sphere strongly suggests that Barnard 68 is indeed an isothermal, pressurecon®ned and self-gravitating cloud. It i ...
... inferred for the Loop I superbubble from X-ray observations with the ROSAT satellite13. The close correspondence of the observed extinction pro®le with that predicted for a Bonnor±Ebert sphere strongly suggests that Barnard 68 is indeed an isothermal, pressurecon®ned and self-gravitating cloud. It i ...
Finding Dark Matter
... Galactic Halo Dark Matter • Rotation velocities are too fast • Radial profile of rotation velocities suggests spherical distribution of dark matter – the Halo • One proposed candidate for the dark matter is in the form of “MAssive Compact Halo Objects” (MACHOs) – These can be detected through “grav ...
... Galactic Halo Dark Matter • Rotation velocities are too fast • Radial profile of rotation velocities suggests spherical distribution of dark matter – the Halo • One proposed candidate for the dark matter is in the form of “MAssive Compact Halo Objects” (MACHOs) – These can be detected through “grav ...
Follow Proxima Centauri - Department of Physics and Astronomy
... the Earth moves 1 astronomical unit would be 1 arcsecond. A star 2 parsecs away would have a parallax of 1/2 arcsecond, 3 parsecs and it would be 1/3 ..., 10 parsecs 1/10th and so on. A parsec is 3.26 light years, and Proxima Centauri is 1.3 parsecs. If we could watch it appear to move during the ye ...
... the Earth moves 1 astronomical unit would be 1 arcsecond. A star 2 parsecs away would have a parallax of 1/2 arcsecond, 3 parsecs and it would be 1/3 ..., 10 parsecs 1/10th and so on. A parsec is 3.26 light years, and Proxima Centauri is 1.3 parsecs. If we could watch it appear to move during the ye ...
Here - Astrophysics Research Institute
... • M76 therefore rises in the EAST and moves to the left. • Our target is already >2 hours over, i.e. its in the west; it therefore makes sense that Azimuth is a large (or negative) angle, since A is measured East of North. ...
... • M76 therefore rises in the EAST and moves to the left. • Our target is already >2 hours over, i.e. its in the west; it therefore makes sense that Azimuth is a large (or negative) angle, since A is measured East of North. ...
Variations in the Star Formation Efficiency of the Dense Molecular
... a few positions because the throw would have intersected the galaxy. In those cases we adopted a position-switching scheme and selected a suitable OFF position with coordinates chosen based on the HERACLES maps. We checked the focus of the telescope on planets or bright quasars at the beginning of e ...
... a few positions because the throw would have intersected the galaxy. In those cases we adopted a position-switching scheme and selected a suitable OFF position with coordinates chosen based on the HERACLES maps. We checked the focus of the telescope on planets or bright quasars at the beginning of e ...
Hubble Deep Field
The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area 2.5 arcminutes across, about one 24-millionth of the whole sky, which is equivalent in angular size to a 65 mm tennis ball at a distance of 100 metres. The image was assembled from 342 separate exposures taken with the Space Telescope's Wide Field and Planetary Camera 2 over ten consecutive days between December 18 and December 28, 1995.The field is so small that only a few foreground stars in the Milky Way lie within it; thus, almost all of the 3,000 objects in the image are galaxies, some of which are among the youngest and most distant known. By revealing such large numbers of very young galaxies, the HDF has become a landmark image in the study of the early universe, with the associated scientific paper having received over 900 citations by the end of 2014.Three years after the HDF observations were taken, a region in the south celestial hemisphere was imaged in a similar way and named the Hubble Deep Field South. The similarities between the two regions strengthened the belief that the universe is uniform over large scales and that the Earth occupies a typical region in the Universe (the cosmological principle). A wider but shallower survey was also made as part of the Great Observatories Origins Deep Survey. In 2004 a deeper image, known as the Hubble Ultra-Deep Field (HUDF), was constructed from a few months of light exposure. The HUDF image was at the time the most sensitive astronomical image ever made at visible wavelengths, and it remained so until the Hubble Extreme Deep Field (XDF) was released in 2012.