The Eagle Nebula is a young open cluster of stars in the constellation Serpens, discovered by Jean-Philippe de Cheseaux in 1745–46. Both the "Eagle" and the "Star Queen" refer to visual impressions of the dark silhouette near the center of the nebula, an area made famous as the "Pillars of Creation" imaged by the Hubble Space Telescope. The nebula contains several active star-forming gas and dust regions, including the aforementioned Pillars of Creation. The Eagle Nebula lies in the Sagittarius Arm of the Milky Way.
Catalina Sky Survey is an astronomical survey to discover comets and asteroids. It is conducted at the Steward Observatory's Catalina Station, located near Tucson, Arizona, in the United States.
Kaoru Ikeya is a Japanese amateur astronomer who discovered a number of comets.
A transit of Mercury across the Sun takes place when the planet Mercury passes directly (transits) between the Sun and a superior planet, becoming visible against the solar disk. During a transit, Mercury appears as a tiny black dot moving across the disk of the Sun.
Astronomy Picture of the Day (APOD) is a website provided by NASA and Michigan Technological University (MTU). According to the website, "Each day a different image or photograph of our universe is featured, along with a brief explanation written by a professional astronomer." The photograph does not necessarily correspond to a celestial event on the exact day that it is displayed, and images are sometimes repeated. However, the pictures and descriptions often relate to current events in astronomy and space exploration. The text has several hyperlinks to more pictures and websites for more information. The images are either visible spectrum photographs, images taken at non-visible wavelengths and displayed in false color, video footage, animations, artist's conceptions, or micrographs that relate to space or cosmology. Past images are stored in the APOD Archive, with the first image appearing on June 16, 1995. This initiative has received support from NASA, the National Science Foundation, and MTU. The images are sometimes authored by people or organizations outside NASA, and therefore APOD images are often copyrighted, unlike many other NASA image galleries.
Herschel is a large crater in the leading hemisphere of the Saturnian moon Mimas, on the equator at 100° longitude. It is named after the 18th-century astronomer William Herschel, who discovered Mimas in 1789.
The Crescent Nebula is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth. It was discovered by William Herschel in 1792. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.
Solar physics is the branch of astrophysics that specializes in the study of the Sun. It deals with detailed measurements that are possible only for our closest star. It intersects with many disciplines of pure physics, astrophysics, and computer science, including fluid dynamics, plasma physics including magnetohydrodynamics, seismology, particle physics, atomic physics, nuclear physics, stellar evolution, space physics, spectroscopy, radiative transfer, applied optics, signal processing, computer vision, computational physics, stellar physics and solar astronomy.
The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus.
The Medusa Nebula is a planetary nebula in the constellation of Gemini. It is also known as Abell 21 and Sharpless 2-274. It was originally discovered in 1955 by University of California, Los Angeles astronomer George O. Abell, who classified it as an old planetary nebula. Until the early 1970s, the nebula was thought to be a supernova remnant. With the computation of expansion velocities and the thermal character of the radio emission, Soviet astronomers in 1971 concluded that it was most likely a planetary nebula. As the nebula is so large, its surface brightness is very low, with surface magnitudes of between +15.99 and +25 reported.
A bipolar nebula is a type of nebula characterized by two lobes either side of a central star. About 10-20% of planetary nebulae are bipolar.
NGC 7635, also known as the Bubble Nebula, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.
The Lowell crater is a large impact crater on Aonia Terra in the Thaumasia quadrangle of Mars. The crater is about 203 kilometers in diameter. Lowell is an example of a well-preserved peak ring crater on Mars.
Proctor is a large crater in the Noachis quadrangle of Mars. It measures 168.2 kilometres in diameter and was named after Richard A. Proctor, a British astronomer (1837–1888).
Simeis 147, also known as the Spaghetti Nebula, SNR G180.0-01.7 or Sharpless 2-240, is a supernova remnant (SNR) in the Milky Way, straddling the border between the constellations Auriga and Taurus. Discovered in 1952 at the Crimean Astrophysical Observatory using a 25-inch Schmidt-Cassegrain telescope, it is difficult to observe due to its extremely low brightness.
The Dark Doodad Nebula is a dark nebula near the globular cluster NGC 4372, much closer than the centre of the galaxy and in the galactic plane, having a length of nearly three degrees of arc. Although officially unnamed, this long molecular cloud has come to be known under this name. It can be found in the southern constellation of Musca with strong binoculars.
C/2009 R1 (McNaught), one of more than fifty comets known as Comet McNaught, is a non-periodic comet discovered by British-Australian astronomer Robert H. McNaught on September 9, 2009, using the Uppsala Southern Schmidt Telescope at Siding Spring Observatory in New South Wales, Australia. The discovery was confirmed the same day at the Optical Ground Station telescope at Tenerife. After the discovery, earlier images of the comet were found from July 20, August 1, and August 18, 2009. It is believed C/2009 R1 will leave the Solar System permanently.
The Far 3 kpc Arm was discovered in 2008 by astronomer Tom Dame, while preparing a talk on the Galaxy's spiral arms for a meeting of the 212th American Astronomical Society. It is one of Milky Way's spiral arms and it is located in the first galactic quadrant at a distance of 3 kpc from the galactic center. Along with the Near 3 kpc Arm whose existence is known since the mid-1950s, the counterpart inner arms establish our Galaxy's simple symmetry.
Dr. Robert J. Nemiroff is a Professor of Physics at Michigan Technological University. He received his Ph.D. from the University of Pennsylvania in Astronomy and Astrophysics in 1987 and his B.S. from Lehigh University in Engineering Physics in 1982. He is an active researcher with interests that include gamma-ray bursts, gravitational lensing, and cosmology, and is the cofounder and coeditor of Astronomy Picture of the Day (APOD), the home page of which receives over a million hits a day, approximately 20% of nasa.gov traffic. He is married and has one daughter.
Abell 7 is a faint planetary nebula located 1800 light-years away in the constellation of Lepus. It has a generally spherical shape about 8 light-years in diameter. Within the sphere are complex details that are brought out by narrowband filters. Abell 7 is estimated to be only 20,000 years old, but the central star, a fading white dwarf, is estimated to be some 10 billion years old.
