Observations, Modeling and Theory of Debris Disks
... (≥ 60 µm), corresponding to cold (∼ at 10s to 100s of AU. The debris disks detected with IRAS were Kuiper belt analogues seen around ∼ 15% of main sequence stars (Aumann 1985). Rhee et al. (2007) have reanalyzed IRAS data and found the detection rate around nearby A stars to be 20%. In the past deca ...
... (≥ 60 µm), corresponding to cold (∼ at 10s to 100s of AU. The debris disks detected with IRAS were Kuiper belt analogues seen around ∼ 15% of main sequence stars (Aumann 1985). Rhee et al. (2007) have reanalyzed IRAS data and found the detection rate around nearby A stars to be 20%. In the past deca ...
THE PRIMORDIAL HELIUM ABUNDANCE Manuel Peimbert
... the study of cosmology and the chemical evolution of galaxies. Over the years the increase in the accuracy of the helium abundance by mass, Y, of different objects and in the accuracy of the predictions of the primordial helium abundance by unit mass, YP (also known as the primordial helium mass fra ...
... the study of cosmology and the chemical evolution of galaxies. Over the years the increase in the accuracy of the helium abundance by mass, Y, of different objects and in the accuracy of the predictions of the primordial helium abundance by unit mass, YP (also known as the primordial helium mass fra ...
Observations, Modeling and Theory of Debris Disks
... (≥ 60 µm), corresponding to cold (∼ at 10s to 100s of AU. The debris disks detected with IRAS were Kuiper belt analogues seen around ∼ 15% of main sequence stars (Aumann 1985). Rhee et al. (2007) have reanalyzed IRAS data and found the detection rate around nearby A stars to be 20%. In the past deca ...
... (≥ 60 µm), corresponding to cold (∼ at 10s to 100s of AU. The debris disks detected with IRAS were Kuiper belt analogues seen around ∼ 15% of main sequence stars (Aumann 1985). Rhee et al. (2007) have reanalyzed IRAS data and found the detection rate around nearby A stars to be 20%. In the past deca ...
The Milky Way disk
... I will focus only on the Local arm, the closest to us, the one which the Sun is located in. (Morgan et al., 1952) originally referred to this spiral feature as a spur, a bifurcation departing from the Sagittarius arm in the first quadrant, close to the huge HII region W51 (Avedisova, 1985), and disp ...
... I will focus only on the Local arm, the closest to us, the one which the Sun is located in. (Morgan et al., 1952) originally referred to this spiral feature as a spur, a bifurcation departing from the Sagittarius arm in the first quadrant, close to the huge HII region W51 (Avedisova, 1985), and disp ...
Astronomy 114 - Department of Astronomy
... Interstellar gas and dust are common in the disk of the Galaxy Interstellar medium (ISM) Diffuse gas (atomic H and molecular hydrogen H2 ) Dust (formed in the envelopes of stars) ...
... Interstellar gas and dust are common in the disk of the Galaxy Interstellar medium (ISM) Diffuse gas (atomic H and molecular hydrogen H2 ) Dust (formed in the envelopes of stars) ...
IMCCE - Observer pages
... Figure: main filters used on the 120cm telescope at OHP The receptors and the observation In the case of observation of phenomena, we need a fast receptor, able to record the light emitted by the objects during a short interval de time, less than one second of time. CCD, video camera or video camera ...
... Figure: main filters used on the 120cm telescope at OHP The receptors and the observation In the case of observation of phenomena, we need a fast receptor, able to record the light emitted by the objects during a short interval de time, less than one second of time. CCD, video camera or video camera ...
Dynamics of small bodies in planetary systems
... can be estimated as long as the level of dust emission has been measured at two or more wavelengths from which its temperature can be estimated. However, such estimates suffer large uncertainties, since the exact temperature of the dust depends on its size and composition (see chapter by Li). Assumi ...
... can be estimated as long as the level of dust emission has been measured at two or more wavelengths from which its temperature can be estimated. However, such estimates suffer large uncertainties, since the exact temperature of the dust depends on its size and composition (see chapter by Li). Assumi ...
The physics and modes of star cluster formation: observations
... infrared wavelengths (e.g. Green & Lada 1996; White et al. 2007). Infrared spectroscopic surveys, especially those done with multi-object spectrographs, can be used to identify accreting objects in a cluster field. However, such observations can be time-consuming and even prohibitive for faint member ...
... infrared wavelengths (e.g. Green & Lada 1996; White et al. 2007). Infrared spectroscopic surveys, especially those done with multi-object spectrographs, can be used to identify accreting objects in a cluster field. However, such observations can be time-consuming and even prohibitive for faint member ...
The phenomena of the satellites of the giant planets
... Figure: main filters used on the 120cm telescope at OHP The receptors and the observation In the case of observation of phenomena, we need a fast receptor, able to record the light emitted by the objects during a short interval de time, less than one second of time. CCD, video camera or video camera ...
... Figure: main filters used on the 120cm telescope at OHP The receptors and the observation In the case of observation of phenomena, we need a fast receptor, able to record the light emitted by the objects during a short interval de time, less than one second of time. CCD, video camera or video camera ...
PH607lec12
... Though many astronomers agree that hierarchical formation seems to be occurring, there are still some wrinkles to the theory. For example, the very most massive galaxies don't seem to be growing at as high a rate as middle-mass galaxies. When astronomers look at the brightest galaxies now compared t ...
... Though many astronomers agree that hierarchical formation seems to be occurring, there are still some wrinkles to the theory. For example, the very most massive galaxies don't seem to be growing at as high a rate as middle-mass galaxies. When astronomers look at the brightest galaxies now compared t ...
a changing cosmos - Whittier Union High School District
... Walter Alvarez from the University of California at Berkeley. He was studying a thin layer of clay between rock layers of the Cretaceous Period (Age of Reptiles) and the Tertiary Period (containing no dinosaurs fossils). The clay layer contained very large amounts of the rare element iridium, which ...
... Walter Alvarez from the University of California at Berkeley. He was studying a thin layer of clay between rock layers of the Cretaceous Period (Age of Reptiles) and the Tertiary Period (containing no dinosaurs fossils). The clay layer contained very large amounts of the rare element iridium, which ...
Nebulae.The Lagoon and Dumbbell Nebulae
... a remnant of a dying star which is approximately 2 times smaller than the Sun. The star is hot and blue with temperature of 85000K (Most of these stars usually turn into red giants. They lose their mass by ejection of the outer gas layers. These layers expand in space, forming a temporary wrap aroun ...
... a remnant of a dying star which is approximately 2 times smaller than the Sun. The star is hot and blue with temperature of 85000K (Most of these stars usually turn into red giants. They lose their mass by ejection of the outer gas layers. These layers expand in space, forming a temporary wrap aroun ...
1 Distance: A History of Parallax and Brief Introduction to Standard
... Earth was met with great skepticism. Those that were aware of the size of the Earth dismissed the notation entirely because it would mean non-stop cataclysm: continents swirling around the axis at hundreds of kilometers per hour causing continuous, extreme wind which would hypothetically cause every ...
... Earth was met with great skepticism. Those that were aware of the size of the Earth dismissed the notation entirely because it would mean non-stop cataclysm: continents swirling around the axis at hundreds of kilometers per hour causing continuous, extreme wind which would hypothetically cause every ...
ADAPTIVE OPTICS ON GROUND
... Therefore, the quad-cell response has to be calibrated, which is achieved by imaging an artificial point source. In addition the response of a quad-cell slope detector is linear only for slopes less than ± θb/2, so it may be variable, depending on seeing or object size. This is the price to pay for ...
... Therefore, the quad-cell response has to be calibrated, which is achieved by imaging an artificial point source. In addition the response of a quad-cell slope detector is linear only for slopes less than ± θb/2, so it may be variable, depending on seeing or object size. This is the price to pay for ...
Pluto Gets Demoted
... years. Its orbit is less circular than the other planets’, but the astronomers still gave Pluto a passing grade. Second, it has to be big enough to form a round or nearly round shape. Check! Like the other planets in our solar system, Pluto passes that test. Third, it has to “clear the neighborhood ...
... years. Its orbit is less circular than the other planets’, but the astronomers still gave Pluto a passing grade. Second, it has to be big enough to form a round or nearly round shape. Check! Like the other planets in our solar system, Pluto passes that test. Third, it has to “clear the neighborhood ...
Concept and performance of multiple laser guide stars for 8-m
... Mirror (DM) corrects the turbulence measured by the reference star. But due to a lack of bright stars near the science object, the sky coverage of such systems is small even at the near infrared wavelengths. The straight-forward idea is to use artificial objects as reference stars. In 1985, Foy and ...
... Mirror (DM) corrects the turbulence measured by the reference star. But due to a lack of bright stars near the science object, the sky coverage of such systems is small even at the near infrared wavelengths. The straight-forward idea is to use artificial objects as reference stars. In 1985, Foy and ...
PDF - STRW Local - Universiteit Leiden
... – e.g. our role in instrument development. Frans Snik, who won a Starters Grant from the European Research Council this year, and Matthew Kenworthy write about new smart ways to search for faint planets orbiting bright stars. This is enabled using liquid crystals in coronagraphs reaching extremely h ...
... – e.g. our role in instrument development. Frans Snik, who won a Starters Grant from the European Research Council this year, and Matthew Kenworthy write about new smart ways to search for faint planets orbiting bright stars. This is enabled using liquid crystals in coronagraphs reaching extremely h ...
TAKAHASHI
... refractor. This newly designed objective produce an extremely high order of color correction, very small stars, superb contrast and greatly reduced field curvature. The optionally available flatteners, reducer makes the TOA- into the perfect flat field CCD or astro camera. The Extender TOA 1.6X is t ...
... refractor. This newly designed objective produce an extremely high order of color correction, very small stars, superb contrast and greatly reduced field curvature. The optionally available flatteners, reducer makes the TOA- into the perfect flat field CCD or astro camera. The Extender TOA 1.6X is t ...
Grade 9 Space Review 50KB Nov 18 2009 10:52:00 AM
... 3. Explain the term zodiac and its connection to planetary motion. Write your answer in complete sentences. 4. Choose a major constellation that can be seen from Ontario in the winter and sketch its approximate appearance. 5. Draw a sketch to show how the Big Dipper can be used to locate Polaris. 6. ...
... 3. Explain the term zodiac and its connection to planetary motion. Write your answer in complete sentences. 4. Choose a major constellation that can be seen from Ontario in the winter and sketch its approximate appearance. 5. Draw a sketch to show how the Big Dipper can be used to locate Polaris. 6. ...
Spitzer Space Telescope
The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space observatory launched in 2003. It is the fourth and final of the NASA Great Observatories program.The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium supply was exhausted. This occurred on 15 May 2009. Without liquid helium to cool the telescope to the very low temperatures needed to operate, most of the instruments are no longer usable. However, the two shortest-wavelength modules of the IRAC camera are still operable with the same sensitivity as before the cryogen was exhausted, and will continue to be used in the Spitzer Warm Mission. All Spitzer data, from both the primary and warm phases, are archived at the Infrared Science Archive (IRSA).In keeping with NASA tradition, the telescope was renamed after its successful demonstration of operation, on 18 December 2003. Unlike most telescopes that are named after famous deceased astronomers by a board of scientists, the new name for SIRTF was obtained from a contest open to the general public.The contest led to the telescope being named in honor of astronomer Lyman Spitzer, who had promoted the concept of space telescopes in the 1940s. Spitzer wrote a 1946 report for RAND Corporation describing the advantages of an extraterrestrial observatory and how it could be realized with available or upcoming technology. He has been cited for his pioneering contributions to rocketry and astronomy, as well as ""his vision and leadership in articulating the advantages and benefits to be realized from the Space Telescope Program.""The US$800 million Spitzer was launched from Cape Canaveral Air Force Station, on a Delta II 7920H ELV rocket, Monday, 25 August 2003 at 13:35:39 UTC-5 (EDT).It follows a heliocentric instead of geocentric orbit, trailing and drifting away from Earth's orbit at approximately 0.1 astronomical unit per year (a so-called ""earth-trailing"" orbit). The primary mirror is 85 centimeters (33 in) in diameter, f/12, made of beryllium and is cooled to 5.5 K (−449.77 °F). The satellite contains three instruments that allow it to perform astronomical imaging and photometry from 3 to 180 micrometers, spectroscopy from 5 to 40 micrometers, and spectrophotometry from 5 to 100 micrometers.