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The UBV Photoelectric Photometry Catalogue, or UBV M, is the star brightness catalogue that complies to the UBV photometric system developed by astronomer Harold Johnson.
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The UBV Photoelectric Photometry Catalogue, or UBV M, is the star brightness catalogue that complies to the UBV photometric system developed by astronomer Harold Johnson.
The early edition of 1968 by Blanco, sometimes referred as simply the "Photoelectric Catalogue" or UBV was replaced by the Mermilliod edition UBV M in 1987 and extended in 1993. As the atmospheric extinction problem associated with the UBV photometric system became evident, the UBV Photoelectric Photometry Catalogue was phased-out in 2000. [ citation needed ]
The UBV catalog data format is in plain text. After uncompressing by unzip or gunzip it can be seen by any text viewers or by the online ADC viewer. Specifications for the catalog format are provided at the download sites.
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Photometry, from Greek photo- ("light") and -metry ("measure"), is a technique used in astronomy that is concerned with measuring the flux or intensity of light radiated by astronomical objects. This light is measured through a telescope using a photometer, often made using electronic devices such as a CCD photometer or a photoelectric photometer that converts light into an electric current by the photoelectric effect. When calibrated against standard stars of known intensity and colour, photometers can measure the brightness or apparent magnitude of celestial objects.
Atlas, designation 27 Tauri, is a triple star system in the constellation of Taurus. It is a member of the Pleiades, an open star cluster (M45). It is 431 light-years away, and is 3.92 degrees north of the ecliptic.
Rho Ursae Majoris (ρ UMa) is the Bayer designation for a solitary star in the northern circumpolar constellation of Ursa Major. It is faintly visible to the naked eye with an apparent visual magnitude of 4.74. The distance to this star, based upon an annual parallax shift of 10.37 mas, is around 315 light years.
ν Virginis, Latinized as Nu Virginis, is a single star in the zodiac constellation of Virgo, located at the western tip of the classic constellation and nearly due south of the prominent star Denebola. It is a red-hued star with an apparent visual magnitude of 4.04 and can be seen with the naked eye. Because the star lies near the ecliptic it is subject to occultations by the Moon. Parallax measurements provide an estimated distance of around 294 light years from the Sun, and it is drifting further away with a radial velocity of +50 km/s.
Tau Virginis is a single star in the zodiac constellation Virgo. With an apparent visual magnitude of 4.28, it is faintly visible to the naked eye. The distance to Tau Virginis, based upon parallax measurements, is approximately 225 light years with a margin of error of ±3 light years.
15 Arietis is a single variable star in the northern constellation of Aries. 15 Arietis is the Flamsteed designation; it also bears the variable star designation AV Arietis. It has an apparent visual magnitude of 5.74, which is just bright enough to be visible to the naked eye from dark suburban skies. An annual parallax shift of 5.84 mas corresponds to a physical distance of approximately 560 light-years from Earth. At that distance, the star's brightness is reduced by 0.33 in magnitude because of extinction from interstellar gas and dust.
26 Aurigae is a binary star system in the northern constellation of Auriga. It is visible to the naked eye as a faint star with an apparent visual magnitude of 5.41.
κ Lyrae, Latinized as Kappa Lyrae, is a solitary star in the northern constellation of Lyra, near the constellation border with Hercules. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.33. This object is located approximately 238 light years from the Sun based on parallax, but is moving closer with a radial velocity of −24 km/s.
HD 36678 is single star in the northern constellation of Auriga. This star is dimly visible to the naked eye with an apparent visual magnitude of 5.83. It is located at a distance of approximately 840 light years from the Sun based on parallax. This is an aging red giant star with a stellar classification of M0III. It is currently on the asymptotic giant branch of the HR diagram, and has expanded to ~63 times the radius of the Sun. The star is radiating ~875 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,950 K.
45 Herculis is a solitary variable star in the northern constellation Hercules. It has the Bayer designation l Herculis and the variable star designation V776 Herculis. The Flamsteed designation for this star comes from the publication Historia Coelestis Britannica by John Flamsteed. It is the 45th star in Flamsteed list of stars in the constellation Hercules, and is visible to the naked eye with a baseline apparent visual magnitude of 5.22. Parallax measurements show this star to be about 400 light-years away from the Solar System. It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.
Nu Herculis, Latinized from ν Herculis, is a binary and variable star in the constellation of Hercules. With an apparent magnitude of about 4.4, it is faintly visible to the naked eye. Parallax measurements made by the Hipparcos spacecraft put it at a distance of about 860 light years.
Sigma Piscium is a main-sequence star in the zodiac constellation of Pisces. It has an apparent magnitude of +5.50, meaning it is barely visible to the naked eye, according to the Bortle scale. While parallax measurements by the Hipparcos spacecraft give a distance of approximately 430 light years, dynamical parallax measurements put it slightly closer, at 368 light-years from Earth.
HD 93194 is a star in the constellation Carina. Its apparent magnitude is 4.79. Its parent cluster is IC 2602.
HD 93607 is a star in the constellation Carina. Its apparent magnitude is 4.87. Its parent cluster is IC 2602.
23 Comae Berenices is a binary star system in the northern constellation of Coma Berenices, situated a few degrees away from the North Galactic Pole. It is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 4.80. The system is located around 310 light years away from the Sun, based on parallax. It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.
1 Geminorum is a star in the constellation Gemini. Its apparent magnitude is 4.15.
106 Herculis is a variable star in the northern constellation Hercules. It is visible to the naked eye as a faint, red-hued point of light with a baseline apparent visual magnitude of 4.96. Based on its parallax, it is estimated to lie 383 light-years away from the Sun. The star is moving closer to the Earth with a heliocentric radial velocity of -35 km/s.
HD 100307 is a suspected variable star in the constellation of Hydra. Its apparent magnitude is 6.16, but interstellar dust makes it appear 0.346 magnitudes dimmer than it should be. It is located some 340 light-years away, based on parallax.
47 Ophiuchi is a binary star in the constellation Serpens. The combined apparent magnitude of the system is 4.54. The system is located about 98.1 light-years, or 30.1 parsecs away, based on its parallax as measured by Hipparcos.
ψ Leonis, is a solitary star located in the zodiac constellation of Leo, to the east-northeast of Regulus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.38. Based upon stellar parallax measurements, it is located around 95 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an absorption factor of 0.3 due to interstellar dust.