Photometry (astronomy) in the context of "Flux"

271 Penthesilea is a mid-sized main belt asteroid that was discovered by Viktor Knorre on 13 October 1887 in Berlin. It was his last asteroid discovery. The asteroid was named after Penthesilea, the mythical Greek queen of the Amazons.

Photometric observations of this asteroid were made in early 2009 at the Organ Mesa Observatory in Las Cruces, New Mexico. The resulting light curve shows a synodic rotation period of 18.787 ± 0.001 hours with a brightness variation of 0.32 ± 0.04 in magnitude.

The Two Micron All-Sky Survey (2MASS) was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and at the Cerro Tololo Inter-American Observatory in Chile, each using a 1.3-meter telescope for the Northern and Southern Hemisphere, respectively. It was conducted in the short-wavelength infrared at three distinct frequency bands (J, H, and K) near 2 micrometres, from which the photometric survey with its HgCdTe detectors derives its name.

2MASS produced an astronomical catalog with over 300 million observed objects, including minor planets of the Solar System, brown dwarfs, low-mass stars, nebulae, star clusters and galaxies. In addition, 1 million objects were cataloged in the 2MASS Extended Source Catalog (2MASX). The cataloged objects are designated with a "2MASS" and "2MASX" prefix, respectively.

158 Koronis is a main-belt asteroid that was discovered by Russian astronomer Viktor Knorre on January 4, 1876, from the Berlin observatory. It was the first of his four asteroid discoveries. The meaning of the asteroid name is uncertain, but it may come from Coronis the mother of Asclepius from Greek mythology. Alternatively, it may come from Coronis, a nymph of the Hyades sisterhood. The Koronis family is named after this asteroid.

From its spectrum this is classified as an S-type asteroid, indicating a stony composition. Photometric observations show a synodic rotation period of 14.206 ± 0.002 hours with a brightness variation of 0.28–0.43 in magnitude. A subsequent study at the Altimira Observatory during 2010 was in agreement with this estimate, yielding a rotation period of 14.208 ± 0.040 hours. Based on a model constructed from the lightcurve, the shape of Koronis resembles that of 243 Ida, an asteroid in the same family, although it is a bit larger. [1]

University of Canterbury Mount John Observatory (UCMJO), previously known as Mt John University Observatory (MJUO), is New Zealand's premier astronomical research observatory. It is situated at 1,029 metres (3,376 ft) ASL atop Mount John at the northern end of the Mackenzie Basin in the South Island, and was established in 1965. There are many telescopes on site including: one 0.4 metre, two 0.6 metre, one 1.0 metre, and a 1.8 metre MOA telescope. The nearest population centre is the resort town of Lake Tekapo. Approximately 20% of nights at UCMJO are photometric, with a larger number available for spectroscopic work and direct imaging photometry.

UCMJO is operated by the University of Canterbury, and is the home of HERCULES (High Efficiency and Resolution Canterbury University Large Echelle Spectrograph), and the observational wing of the Japanese/New Zealand MOA collaboration (Microlensing Observations in Astrophysics) led by Yasushi Muraki of Nagoya University. A Japanese funded, 1.8 metre telescope was used initially by the MOA Project, before handover to the University of Canterbury at the conclusion of the MOA Project in 2012.

The Geneva Observatory (French: Observatoire de Genève, German: Observatorium von Genf) is an astronomical observatory at Sauverny (CH) in the municipality of Versoix, Canton of Geneva, in Switzerland. It shares its buildings with the astronomy department of the École Polytechnique Fédérale de Lausanne. It has been active in discovering exoplanets, in stellar photometry, modelling stellar evolution, and has been involved in the European Space Agency's Hipparcos, INTEGRAL, Gaia, and Planck missions.

In 1995, the first exoplanet found orbiting a main-sequence star, 51 Pegasi b, was discovered by two scientists of the observatory, Michel Mayor and Didier Queloz, using the radial velocity method with the 1.9-metre telescope at Haute-Provence Observatory in France. Mayor and Queloz were awarded (half of) the Nobel Prize in Physics 2019 for this discovery.

A small telescope is generally considered by professional astronomers to be any reflecting telescope with a primary mirror that is less than 2 metres (80 in) in diameter.By amateur standards, a small telescope can have a primary mirror/aperture less than 6–10 inches (150–250 mm) in diameter. Little if any professional-level research is performed with refracting telescopes in the modern era of astronomy.

Small telescopes dominate astronomical research in the fields of asteroid/comet discovery/observation, variable star photometry, supernova/nova discovery, and colorimetry/polarimetry of the Solar System's planets.

In astronomy, limiting magnitude is the faintest apparent magnitude of a celestial body that is detectable or detected by a given instrument.

In some cases, limiting magnitude refers to the upper threshold of detection. In more formal uses, limiting magnitude is specified along with the strength of the signal (e.g., "10th magnitude at 20 sigma"). Sometimes limiting magnitude is qualified by the purpose of the instrument (e.g., "10th magnitude for photometry") This statement recognizes that a photometric detector can detect light far fainter than it can reliably measure.

An astronomical filter is a telescope accessory consisting of an optical filter used by amateur astronomers to improve the details and contrast of celestial objects, either for viewing or for photography. Research astronomers, on the other hand, use various band-pass filters for photometry on telescopes, in order to obtain measurements which reveal objects' astrophysical properties, such as stellar classification and placement of a celestial body on its Wien curve.

Most astronomical filters work by blocking a specific part of the color spectrum above and below a bandpass, significantly increasing the signal-to-noise ratio of the interesting wavelengths, and so making the object gain detail and contrast. While the color filters transmit certain colors from the spectrum and are usually used for observation of the planets and the Moon, the polarizing filters work by adjusting the brightness, and are usually used for the Moon. The broad-band and narrow-band filters transmit the wavelengths that are emitted by the nebulae (by the hydrogen and oxygen atoms), and are frequently used for reducing the effects of light pollution.

Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. This star is relatively close at only 25 light-years (7.7 parsecs) from the Sun, and one of the most luminous stars in the Sun's neighborhood, being intrinsically brighter than any star nearer to the sun. It is the fifth-brightest star in the night sky, and the second-brightest star in the northern celestial hemisphere, after Arcturus.

Vega has been extensively studied by astronomers, leading it to be termed "arguably the next most important star in the sky after the Sun". Vega was the northern pole star around 12000 BCE and will be so again around the year 13724, when its declination will be +84° 14′, less than six degrees from the Pole. Vega was the first star other than the Sun to have its image and spectrum photographed. It was one of the first stars whose distance was estimated through parallax measurements. Vega has functioned as the baseline for calibrating the photometric brightness scale and was one of the stars used to define the zero point for the UBV photometric system.