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Course Outline - Tony Bacigalupo
Course Outline - Tony Bacigalupo

A Reappraisal of The Habitability of Planets around M Dwarf Stars
A Reappraisal of The Habitability of Planets around M Dwarf Stars

... which are designated as lowercase m, and absolute magnitudes, which are designated as uppercase M and defined as the apparent magnitude that a star would have if it were at a distance of 10 pc (33 light years) from the observer. Observations were historically made with the naked eye, then eyes with ...
A re-appraisal of the habitability of planets around M dwarf
A re-appraisal of the habitability of planets around M dwarf

... which are designated as lowercase m, and absolute magnitudes, which are designated as uppercase M and defined as the apparent magnitude that a star would have if it were at a distance of 10 pc (!33 light years) from the observer. Observations were historically made with the naked eye, then eyes with ...
Star Formation in the Galaxy, An Observational Overview
Star Formation in the Galaxy, An Observational Overview

... energy that cause increased hydrogen burning in a shell around the core. For a solar type star this eventually leads to the expansion of the star’s outer layers which is accompanied by a drastic increase in the star’s luminosity. Thus begins the post-main sequence phase of stellar evolution during w ...
exoplanet observing for amateurs
exoplanet observing for amateurs

... amateurs to have fun with exoplanets; some are “educational,” some could contribute to a better understanding of exoplanets, and others are aimed at new discoveries. The various options for exoplanet observing are explained in Chapter 3. The advanced amateur may eventually be recruited to become a m ...
exemplars and commentary
exemplars and commentary

... .Barnard’s star was thought to have no flares, due to its age, but one was observed in 2011. The significance of Red Dwarfs to astronomy. Although intelligent life formed around a “G” star for us astronomers think that life will most likely be found around a Red Dwarf. Primarily because their energy ...
1 Astrobiologically Interesting Stars within 10
1 Astrobiologically Interesting Stars within 10

16 Test Review ppt! - Goshen Community Schools
16 Test Review ppt! - Goshen Community Schools

A Compilation of Relevant Articles from MMM`s first 25 years, issues
A Compilation of Relevant Articles from MMM`s first 25 years, issues

... 2.A. 106 million times as far as the Moon, and 9,000 times as far as Neptune. 3.A. Sirius is 8.7 light years distant, Procyon 11.3, Altair 16.6, Fomalhaut 23, and Vega 26 Light Years distant. With a small telescope, you can find Barnard’s Star which is only 5.9 LY from here. 4.A. Stars come bigger, ...
Heliacal Rising of Canopus in Indian Astronomy
Heliacal Rising of Canopus in Indian Astronomy

Observations of the asteroid 4844 Matsuyama
Observations of the asteroid 4844 Matsuyama

... We pronounce our gratitude to associate professor Dr Tanyo Bonev, Director of IA s NAO. We are also thankful to astronomers from National Astronomical Observatory- Rozhen Dinko Dimitrov, Pencho Markishki, Dr Galin Borisov, Andon Kostov. We are grateful to students who study astrophysics from the Uni ...
Superbubble Activity in Star-Forming Galaxies M. S. Oey
Superbubble Activity in Star-Forming Galaxies M. S. Oey

... power and other parameters are well-constrained. This was carried out for eight, young, wind-dominated LMC superbubbles by Oey & Massey (1995), Oey (1996), and Oey & Smedley (1998). The predicted growth rate for the shells was higher than implied by their observed R and v, equivalent to an overestim ...
FIRST STELLAR ABUNDANCES IN THE DWARF IRREGULAR
FIRST STELLAR ABUNDANCES IN THE DWARF IRREGULAR

... stars, thermal pulsing in low and intermediate mass AGB stars. Thus, more elements than just those observed in nebulae need to be measured, since each have different formation sites which sample different constituents. The α elements like oxygen are created primarily in short-lived massive stars, wh ...
Distance determination for RAVE stars using stellar models
Distance determination for RAVE stars using stellar models

... spirals, and finally dwarf galaxies. The power spectrum is used to measure the power of density perturbations on a certain scale. The current cosmological model predicts a HarrisonZel’dovich spectrum (P (k) ∝ k, where k is the wavenumber). This power spectrum predicts more power on small scale, so t ...
To Be or Not to Be: The Mysteries of Disk Formation Around Rapidly
To Be or Not to Be: The Mysteries of Disk Formation Around Rapidly

... Putting the Spin on Be Stars Why are Be stars rotating so quickly? • born with high angular momentum • experiencing a re-distribution of internal angular momentum near the conclusion of core hydrogen burning • received mass and angular momentum through mass transfer from a binary companion (this mu ...
Test Ch. 27 Multiple Choice Identify the choice that best completes
Test Ch. 27 Multiple Choice Identify the choice that best completes

... Astronomers theorize that a black hole can be located by observing its effect on a companion star. Just before matter from a companion star is pulled into a black hole, it gives off X rays. Astronomers try to locate the black holes by detecting these X rays from the earth. ...
The Circumstellar Environments of Young Stars at AU Scales
The Circumstellar Environments of Young Stars at AU Scales

on the pms star hbc 498 and its associated nebulous stars1
on the pms star hbc 498 and its associated nebulous stars1

... reference system were made following usual procedures (Mitchell 1960) with the RainBow.v01 photoelectric photometry reduction package (Chavarrı́a, de Lara, & Chavarrı́a-K 2000). The night of 1996 November 23 was photometric, but only HBC 495 and DL Ori/G2 were measured with sufficient precision to o ...
There are 88 constellations in the sky around the Earth. 12 are the
There are 88 constellations in the sky around the Earth. 12 are the

November News Letter - Boise Astronomical Society
November News Letter - Boise Astronomical Society

... stars located in the middle of the rectangle of Orion’s body; this is Orion’s Belt. If you have a pair of binoculars handy, then scan downward from the middle star in Orion’s Belt. These stars represent his sword and the second star in the sword should look a little fuzzy. That fuzzy spot is located ...
Homework #9 (Ch. 21)
Homework #9 (Ch. 21)

University of Manitoba Colloquium (ppt version) - LIGO
University of Manitoba Colloquium (ppt version) - LIGO

The Norma cluster (ACO3627) – II. The near-infrared Ks
The Norma cluster (ACO3627) – II. The near-infrared Ks

... seem to have a steeper bright end than those without cD galaxies. Often the brightest galaxy is excluded to obtain a better fit, particularly in cD clusters. The Schechter parameters have also been found to vary depending on the region sampled within the cluster, the size of the area and the limitin ...
ASTRO-114--Lecture 40-
ASTRO-114--Lecture 40-

... And also, if you look down at the bottom, we have the white dwarfs. They’re hot but they’re not big and bright. They’re different again. Well, what you’re seeing are the normal stars that are on the main sequence and what you’re also seeing on this same graph are what stars turn into as they change. ...
SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN
SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN

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Observational astronomy



Observational astronomy is a division of the astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models. It is the practice of observing celestial objects by using telescopes and other astronomical apparatus.As a science, the study of astronomy is somewhat hindered in that direct experiments with the properties of the distant universe are not possible. However, this is partly compensated by the fact that astronomers have a vast number of visible examples of stellar phenomena that can be examined. This allows for observational data to be plotted on graphs, and general trends recorded. Nearby examples of specific phenomena, such as variable stars, can then be used to infer the behavior of more distant representatives. Those distant yardsticks can then be employed to measure other phenomena in that neighborhood, including the distance to a galaxy.Galileo Galilei turned a telescope to the heavens and recorded what he saw. Since that time, observational astronomy has made steady advances with each improvement in telescope technology.A traditional division of observational astronomy is given by the region of the electromagnetic spectrum observed: Optical astronomy is the part of astronomy that uses optical components (mirrors, lenses and solid-state detectors) to observe light from near infrared to near ultraviolet wavelengths. Visible-light astronomy (using wavelengths that can be detected with the eyes, about 400 - 700 nm) falls in the middle of this range. Infrared astronomy deals with the detection and analysis of infrared radiation (this typically refers to wavelengths longer than the detection limit of silicon solid-state detectors, about 1 μm wavelength). The most common tool is the reflecting telescope but with a detector sensitive to infrared wavelengths. Space telescopes are used at certain wavelengths where the atmosphere is opaque, or to eliminate noise (thermal radiation from the atmosphere). Radio astronomy detects radiation of millimetre to dekametre wavelength. The receivers are similar to those used in radio broadcast transmission but much more sensitive. See also Radio telescopes. High-energy astronomy includes X-ray astronomy, gamma-ray astronomy, and extreme UV astronomy, as well as studies of neutrinos and cosmic rays.Optical and radio astronomy can be performed with ground-based observatories, because the atmosphere is relatively transparent at the wavelengths being detected. Observatories are usually located at high altitudes so as to minimise the absorption and distortion caused by the Earth's atmosphere. Some wavelengths of infrared light are heavily absorbed by water vapor, so many infrared observatories are located in dry places at high altitude, or in space.The atmosphere is opaque at the wavelengths used by X-ray astronomy, gamma-ray astronomy, UV astronomy and (except for a few wavelength ""windows"") far infrared astronomy, so observations must be carried out mostly from balloons or space observatories. Powerful gamma rays can, however be detected by the large air showers they produce, and the study of cosmic rays is a rapidly expanding branch of astronomy.For much of the history of observational astronomy, almost all observation was performed in the visual spectrum with optical telescopes. While the Earth's atmosphere is relatively transparent in this portion of the electromagnetic spectrum, most telescope work is still dependent on seeing conditions and air transparency, and is generally restricted to the night time. The seeing conditions depend on the turbulence and thermal variations in the air. Locations that are frequently cloudy or suffer from atmospheric turbulence limit the resolution of observations. Likewise the presence of the full Moon can brighten up the sky with scattered light, hindering observation of faint objects.For observation purposes, the optimal location for an optical telescope is undoubtedly in outer space. There the telescope can make observations without being affected by the atmosphere. However, at present it remains costly to lift telescopes into orbit. Thus the next best locations are certain mountain peaks that have a high number of cloudless days and generally possess good atmospheric conditions (with good seeing conditions). The peaks of the islands of Mauna Kea, Hawaii and La Palma possess these properties, as to a lesser extent do inland sites such as Llano de Chajnantor, Paranal, Cerro Tololo and La Silla in Chile. These observatory locations have attracted an assemblage of powerful telescopes, totalling many billion US dollars of investment.The darkness of the night sky is an important factor in optical astronomy. With the size of cities and human populated areas ever expanding, the amount of artificial light at night has also increased. These artificial lights produce a diffuse background illumination that makes observation of faint astronomical features very difficult without special filters. In a few locations such as the state of Arizona and in the United Kingdom, this has led to campaigns for the reduction of light pollution. The use of hoods around street lights not only improves the amount of light directed toward the ground, but also helps reduce the light directed toward the sky.Atmospheric effects (astronomical seeing) can severely hinder the resolution of a telescope. Without some means of correcting for the blurring effect of the shifting atmosphere, telescopes larger than about 15–20 cm in aperture can not achieve their theoretical resolution at visible wavelengths. As a result, the primary benefit of using very large telescopes has been the improved light-gathering capability, allowing very faint magnitudes to be observed. However the resolution handicap has begun to be overcome by adaptive optics, speckle imaging and interferometric imaging, as well as the use of space telescopes.Astronomers have a number of observational tools that they can use to make measurements of the heavens. For objects that are relatively close to the Sun and Earth, direct and very precise position measurements can be made against a more distant (and thereby nearly stationary) background. Early observations of this nature were used to develop very precise orbital models of the various planets, and to determine their respective masses and gravitational perturbations. Such measurements led to the discovery of the planets Uranus, Neptune, and (indirectly) Pluto. They also resulted in an erroneous assumption of a fictional planet Vulcan within the orbit of Mercury (but the explanation of the precession of Mercury's orbit by Einstein is considered one of the triumphs of his general relativity theory).
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