Antares is the brightest star in the constellation of Scorpius. It has the Bayer designation α Scorpii, which is Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by σ Scorpii and τ Scorpii near the center of the constellation. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from an apparent visual magnitude of +0.6 down to +1.6. It is on average the fifteenth-brightest star in the night sky. Antares is the brightest and most evolved stellar member of the Scorpius–Centaurus association, the nearest OB association to the Sun. It is located about 170 parsecs (550 ly) from Earth at the rim of the Upper Scorpius subgroup, and is illuminating the Rho Ophiuchi cloud complex in its foreground.
Aldebaran is a star located in the zodiac constellation of Taurus. It has the Bayer designation α Tauri, which is Latinized to Alpha Tauri and abbreviated Alpha Tau or α Tau. Aldebaran varies in brightness from an apparent visual magnitude 0.75 down to 0.95, making it the brightest star in the constellation, as well as (typically) the fourteenth-brightest star in the night sky. It is positioned at a distance of approximately 65 light-years from the Sun. The star lies along the line of sight to the nearby Hyades cluster.
In astronomy, a light curve is a graph of the light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y-axis and with time on the x-axis. The light is usually in a particular frequency interval or band.
Regulus is the brightest object in the constellation Leo and one of the brightest stars in the night sky. It has the Bayer designation designated α Leonis, which is Latinized to Alpha Leonis, and abbreviated Alpha Leo or α Leo. 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. The system lies approximately 79 light years from the Sun.
An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. 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.
A transit of Mercury across the Sun takes place when the planet Mercury passes directly between the Sun and a superior planet. During a transit, Mercury appears as a tiny black dot moving across the Sun as the planet obscures a small portion of the solar disk. Because of orbital alignments, transits viewed from Earth occur in May or November. The last four such transits occurred on May 7, 2003; November 8, 2006; May 9, 2016; and November 11, 2019. The next will occur on November 13, 2032. A typical transit lasts several hours. Mercury transits are much more frequent than transits of Venus, with about 13 or 14 per century, primarily because Mercury is closer to the Sun and orbits it more rapidly.
The Baily's beads, diamond ring or more rarely double diamond ring effects, are features of total and annular solar eclipses. Although caused by the same phenomenon, they are distinct events during these types of 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. They are named for Francis Baily, who explained the effects in 1836. The diamond ring effects are seen when only one or two beads are left, appearing as shining "diamonds" set in a bright ring around the lunar silhouette.
Delta Capricorni, or δ Capricorni, is a binary star located 38.7 light-years from the Sun in the constellation of Capricornus. The system consists of an eclipsing binary, Delta Capricorni A, and two visual companions that are over 10 magnitudes fainter, labeled B and C. Delta Capricorni A's two components are designated Delta Capricorni Aa and Ab. The primary star, Aa, is a white giant and the combined light of Aa and Ab makes it the brightest star in the constellation.
Tau Tauri, Latinized from τ Tauri, is a quadruple star system in the constellation Taurus. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.33. The distance to this system is approximately about 400 light years based on parallax. The system is moving further from the Earth with a heliocentric radial velocity of +14.6 km/s, and it is a member of the Taurion OB association, located between Orion and Taurus. It is located 0.7 degree north of the ecliptic, and thus is subject to lunar occultations.
Rho Aquarii, Latinized from ρ Aquarii, is the Bayer designation for a binary star system in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of +5.34. Based upon parallax measurements, this star is at a distance of roughly 870 light-years from Earth. It is drifting closer with a radial velocity of –9 km/s. The proximity of this star to the ecliptic means it is subject to lunar occultations.
119 Tauri is a red supergiant star in the constellation Taurus. It is a magnitude 4 star, visible to the naked eye under good observing conditions. A semiregular variable, its angular diameter has been measured at about 10 mas. It is a similar star to Betelgeuse although redder and more distant.
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.
HD 222582 is a multiple star system in the equatorial constellation of Aquarius. It is invisible to the naked eye with an apparent visual magnitude of 7.7, but can be viewed with binoculars or a small telescope. The system is located at a distance of 137 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +12 km/s. It is located close enough to the ecliptic that it is subject to lunar occultations.
54 Ceti is an older Flamsteed designation for a star that is now located within the constellation boundaries of Aries, the Ram. In the present day it is known by star catalogue identifiers like HD 11257 or HR 534. At an apparent visual magnitude of 5.94, it can be seen with the naked eye. The distance to this star, as determined using parallax measurements made during the Hipparcos mission, is approximately 139 light-years, give or take a 6 light-year margin of error. It is located near the ecliptic and hence is subject to occasional occultation by the Moon.
Corralitos Observatory was an astronomical observatory located in the Rough and Ready Hills approximately 30 kilometers (19 mi) west of Las Cruces, New Mexico. It was formally dedicated on October 12, 1965, serving as a remote station of Dearborn Observatory, Northwestern University. In October 1965, a NASA program to detect transient lunar phenomenon (TLP) was begun by the staff. Using two-person observer teams, a total of 6,466 man-hours of lunar observation was recorded. The program was run until 1972 but did not confirm any TLP. Using ninety-eight selected reports of TLPs received from amateurs during this period, 39 were checked from Corralitos Observatory.
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 about 5.7.
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 393.
72 Tauri is a possible binary star in the zodiac constellation of Taurus. It is faintly visible to the naked eye with an apparent visual magnitude of +5.5, although only 0.29° from the brighter υ Tauri. Based upon an annual parallax shift of 7.9 mas seen from Earth, it is around 410 light years from the Sun.
The lunar occultation of Venus refers to a natural phenomenon in which the Moon passes in front of Venus, obstructing it from view on some regions of the Earth. Since the orbital plane of the moon is tilted relative to the ecliptic, occultations only happen about twice a year. A computer search predicts that 101 lunar occultations occur in the date range of 1995–2045.
