Measuring distances to the edge of the local group
... estimating the size of a galaxy based on its rotational velocity, but changed at certain mass limits. Was this caused by an underlying physical phenomenon that we did not understand the mechanics of? Or was it potentially a problem with our measuring techniques? Noordermeer & Verheijen (2007) took a ...
... estimating the size of a galaxy based on its rotational velocity, but changed at certain mass limits. Was this caused by an underlying physical phenomenon that we did not understand the mechanics of? Or was it potentially a problem with our measuring techniques? Noordermeer & Verheijen (2007) took a ...
Maximizing the ExoEarth Candidate Yield from a Future Direct
... We make a number of assumptions and approximations to simplify our estimates of exoEarth candidate yield. We budget one year of exposure time for all exoEarth observations. We do not include overheads associated with the observations (e.g., telescope slew times, coronagraph wavefront correction time ...
... We make a number of assumptions and approximations to simplify our estimates of exoEarth candidate yield. We budget one year of exposure time for all exoEarth observations. We do not include overheads associated with the observations (e.g., telescope slew times, coronagraph wavefront correction time ...
solar system
... Although the magnifying and diminishing properties of convex and concave transparent objects was known in Antiquity, lenses as we know them were introduced in the West ...
... Although the magnifying and diminishing properties of convex and concave transparent objects was known in Antiquity, lenses as we know them were introduced in the West ...
The Swift satellite lives up to its name, revealing cosmic
... in support of an origin for short bursts which is completely different from the massive star origins of their long-duration cousins: the compact binary merger scenario. This scenario was proposed for the origin of short-duration GRBs many years ago and works by allowing the orbits of the two stars t ...
... in support of an origin for short bursts which is completely different from the massive star origins of their long-duration cousins: the compact binary merger scenario. This scenario was proposed for the origin of short-duration GRBs many years ago and works by allowing the orbits of the two stars t ...
the spectral irradiance of the moon
... ring of a fork equatorial mount. The telescopes are RitcheyChrétien design with 8 inch (20 cm) diameter primary mirrors. The focal length for each telescope is set to allow an image of the Moon at perigee to fall entirely within its detector array, close to 1 m for both. The brightness difference b ...
... ring of a fork equatorial mount. The telescopes are RitcheyChrétien design with 8 inch (20 cm) diameter primary mirrors. The focal length for each telescope is set to allow an image of the Moon at perigee to fall entirely within its detector array, close to 1 m for both. The brightness difference b ...
Searching for RR Lyrae Stars in M15
... of the star that contains elements other than hydrogen and helium. It essentially measures the number of times the gas has been reprocessed through previous generations of stars. As mentioned before, RR Lyrae stars are constantly switching between ionization levels in helium. The abundance of helium ...
... of the star that contains elements other than hydrogen and helium. It essentially measures the number of times the gas has been reprocessed through previous generations of stars. As mentioned before, RR Lyrae stars are constantly switching between ionization levels in helium. The abundance of helium ...
Live from McDonald Observatory: Observing Venus: explore how it
... telescope is used for high-‐magnification views of Venus. There is no solar filter used to observe Venus. ...
... telescope is used for high-‐magnification views of Venus. There is no solar filter used to observe Venus. ...
Astrophotography
Astrophotography is a specialized type of photography for recording images of astronomical objects and large areas of the night sky. The first photograph of an astronomical object (the Moon) was taken in 1840, but it was not until the late 19th century that advances in technology allowed for detailed stellar photography. Besides being able to record the details of extended objects such as the Moon, Sun, and planets, astrophotography has the ability to image objects invisible to the human eye such as dim stars, nebulae, and galaxies. This is done by long time exposure since both film and digital cameras can accumulate and sum light photons over these long periods of time. Photography revolutionized the field of professional astronomical research, with long time exposures recording hundreds of thousands of new stars and nebulae that were invisible to the human eye, leading to specialized and ever larger optical telescopes that were essentially big cameras designed to collect light to be recorded on film. Direct astrophotography had an early role in sky surveys and star classification but over time it has given way to more sophisticated equipment and techniques designed for specific fields of scientific research, with film (and later astronomical CCD cameras) becoming just one of many forms of sensor.Astrophotography is a large sub-discipline in amateur astronomy where it is usually used to record aesthetically pleasing images, rather than for scientific research, with a whole range of equipment and techniques dedicated to the activity.