Antares, designated α Scorpii, is on average the fifteenth-brightest star in the night sky, and the brightest object in the constellation of Scorpius. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from apparent magnitude +0.6 to +1.6. Often referred to as "the heart of the scorpion", Antares is flanked by σ Scorpii and τ Scorpii near the center of the constellation.
Aldebaran, designated α Tauri, is a giant star measured to be about 65 light-years from the Sun in the zodiac constellation Taurus. It is the brightest star in Taurus and generally the fourteenth-brightest star in the night sky, though it varies slowly in brightness between magnitude 0.75 and 0.95. Aldebaran is believed to host a planet several times the mass of Jupiter, named Aldebaran b.
In astronomy, a light curve is a graph of light intensity of a celestial object or region, as a function of time. The light is usually in a particular frequency interval or band. Light curves can be periodic, as in the case of eclipsing binaries, Cepheid variables, other periodic variables, and transiting extrasolar planets, or aperiodic, like the light curve of a nova, a cataclysmic variable star, a supernova or a microlensing event or binary as observed during occultation events. The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it.
Regulus, designated α Leonis, is the brightest object in the constellation Leo and one of the brightest stars in the night sky, lying approximately 79 light years from the Sun. Regulus appears singular, but is actually a quadruple star system composed of four stars that are organized into two pairs. The spectroscopic binary Regulus A consists of a blue-white main-sequence star and its companion, which has not yet been directly observed, but is probably a white dwarf. HD 87884 is separated from Regulus by 176″ and is itself a close pair. Regulus, along with five slightly dimmer stars have collectively been called 'the Sickle', which is an asterism that marks the head of Leo.
An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks from view (occults) an object in the background. In this general sense, occultation applies to the visual scene observed from low-flying aircraft when foreground objects obscure distant objects dynamically, as the scene changes over time.
The Apache Point Observatory is an astronomical observatory located in the Sacramento Mountains in Sunspot, New Mexico, United States, approximately 18 miles (29 km) south of Cloudcroft. The observatory is operated by New Mexico State University (NMSU) and owned by the Astrophysical Research Consortium (ARC). Access to the telescopes and buildings is private and restricted.
The Baily's beads effect or diamond ring effect is a feature of total and annular solar eclipses. As the Moon covers the Sun during a solar eclipse, the rugged topography of the lunar limb allows beads of sunlight to shine through in some places while not in others. The effect is named after Francis Baily, who explained the phenomenon in 1836. The diamond ring effect is seen when only one bead is left, appearing as a shining "diamond" set in a bright ring around the lunar silhouette.
Messier 23, also known as NGC 6494, is an open cluster of stars in the northwest of the southern constellation of Sagittarius. It was discovered by Charles Messier in 1764. It can be found in good conditions with binoculars or a modestly sized telescope. It is in front of "an extensive gas and dust network", which there may be no inter-association. It is within 5° the sun's position so can be occulted by the moon.
The Haleakalā Observatory, also known as the Haleakalā High Altitude Observatory Site, is Hawaii's first astronomical research observatory. It is located on the island of Maui and is owned by the Institute for Astronomy of the University of Hawai'i, which operates some of the facilities on the site and leases portions to other organizations. Tenants include the Air Force Research Laboratory (AFRL) and the Las Cumbres Observatory Global Telescope Network (LCOGTN). At over 3,050 meters (10,010 ft) in altitude, the summit of Haleakalā is above one third of the Earths's troposphere and has excellent astronomical seeing conditions.
The European X-ray Observatory Satellite (EXOSAT), originally named HELOS, was an X-ray telescope operational from May 1983 until April 1986 and in that time made 1780 observations in the X-ray band of most classes of astronomical object including active galactic nuclei, stellar coronae, cataclysmic variables, white dwarfs, X-ray binaries, clusters of galaxies, and supernova remnants.
Mount Lemmon Observatory (MLO), also known as the Mount Lemmon Infrared Observatory, is an astronomical observatory located on Mount Lemmon in the Santa Catalina Mountains approximately 28 kilometers (17 mi) northeast of Tucson, Arizona (US). The site in the Coronado National Forest is used with special permission from the U.S. Forest Service by the University of Arizona's Steward Observatory, and contains a number of independently managed telescopes.
119 Tauri is a red supergiant star in the constellation Taurus. It is a semiregular variable and its angular diameter has been measured at about 10 mas.
Ashen light is a hypothesised subtle glow that has been claimed to be seen on the night side of the planet Venus. The phenomenon has not been scientifically confirmed, but has been suggested to be associated with lightning, which there is some evidence for on Venus.
The Moon is the largest natural satellite of and the closest major astronomical object to Earth. The Moon may be observed by using a variety of optical instruments, ranging from the naked eye to large telescopes. The Moon is the only celestial body upon which surface features can be discerned with the unaided eyes of most people.
XEphem is a Motif based ephemeris and planetarium program for Unix-like operating systems developed by Elwood C. Downey.
Tortugas Mountain Observatory (TMO) is an astronomical observatory owned and operated by New Mexico State University (NMSU). It is located on Tortugas Mountain, also known locally as 'A' Mountain, in southern New Mexico (USA), approximately 8 kilometers (5.0 mi) southeast of Las Cruces and 4 kilometers (2.5 mi) east of the NMSU campus. Founded in 1963 under the supervision of Clyde Tombaugh, the observatory focused on observing the planets. Much of the information captured at TMO is now available through the Planetary Data System's Atmospheres Node, which is managed by NMSU. The two-dome observatory building was completed in 1964, though observing began with one of the telescopes in 1963. A second building, with a larger single dome, was completed at the opposite end of the ridgeline of Tortugas Mountain in 1967. Regular use of TMO ceased in 1999 or 2000, but the observatory equipment was not dismantled. In 2008 it was used for the Lunar CRater Observing and Sensing Satellite project. In 2010, efforts to revive the observatory for use by the American Association of Variable Star Observers began. As of 10 June 2011, work on project was reported to be 60-75% done.
24 Scorpii is a star that was originally placed by John Flamsteed within the constellation of Scorpius but in now placed within the southeastern constellation of Ophiuchus. It is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of 4.91. Based on the trigonometric parallax published in Gaia Data Release 2, the star lies approximately 121 parsecs or 390 light years away. It is positioned near the ecliptic and thus is subject to lunar occultations.
N.P. Wieth-Knudsen Observatory is next to Tisvilde Hegn, two hours away from Copenhagen, Denmark, at Margot Nyholms vej 19, 3220 Tisvildeleje, on the outskirts of a small residential area in Tisvilde, away from artificial light generated by larger cities. It was constructed in 1959 by Dr. Niels Palle Wieth-Knudsen (1909–1993), who used the observatory until his death. His biggest contribution to astronomy was the observation of lunar occultations, during which the moon passes in front of stars, the data from which is then used in the accurate determination of the lunar position. This became important during the moon landings during the sixties.
3 Geminorum is a blue supergiant star in the constellation Gemini. It is a small amplitude pulsating variable and a close double star, with a mean combined apparent visual magnitude of 5.75.
The Milwaukee Astronomical Society (MAS) is a 501(c)(3) tax-exempt organization serving amateur astronomers in the greater Milwaukee area since 1932, making it one of the oldest continuously running astronomy clubs in the nation. The MAS operates an observatory, one of the largest amateur club observatories in the world. The current membership is 207.
