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Collinder 135
Collinder 135, known sometimes as the Pi Puppis Cluster, is an open cluster in Puppis constellation. It consists of six stars brighter than 6th magnitude, and a widespread population of fainter stars. It lies in the southern celestial hemisphere near a rich star field. The main component is the star Pi Puppis, which gives to the cluster its common name; it is an red supergiant, orange supergiant with a visual magnitude of 2.71. Two of the 5th magnitude stars are all variable star, variables: NV Puppis is a Gamma Cassiopeiae variable, while NW Puppis is a Beta Cephei variable. References External links *{{commonscat-inlineObserving Cr 135 Open clusters Puppis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cr 135 DSS
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Puppis
Puppis ("poop deck, stern") is a constellation in the southern sky. It was originally part of the Former constellations, traditional constellation of Argo Navis (the ship of Jason and the Argonauts), which was divided into three parts, the other two being Carina (constellation), Carina (the keel and hull), and Vela (constellation), Vela (the sails). Puppis is the largest of the three constellations in square degrees. It is one of the 88 modern constellations recognized by the International Astronomical Union. History The constellation of Argo Navis is recorded in Ancient Greece, Greek texts, derived from ancient Egypt around 1000 BC. According to Plutarch, its equivalent in Egyptian astronomy was the "Boat of Osiris". As Argo Navis was roughly 28% larger than the next largest constellation, Hydra (constellation), Hydra, it was sub-divided into three sections in 1752 by the French astronomer Nicolas Louis de Lacaille, including Puppis, which he referred to as "''Argûs in puppi'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collinder Catalogue
The Collinder catalogue is a catalogue of 471 open clusters compiled by Swedish astronomer Per Collinder. It was published in 1931 as an appendix to Collinder's paper ''On structural properties of open galactic clusters and their spatial distribution''. The catalogue contains 452 open clusters, 11 globular clusters, 6 Asterism (astronomy), asterisms, 1 Stellar kinematics#Moving groups, stellar moving group, and 1 Stellar kinematics#Stellar associations, stellar association. Catalogue objects are denoted by ''Collinder'', e.g. "Collinder 399". Dated prefixes include as ''Col + catalogue number'', or ''Cr + catalogue number'', e.g. "Cr 399". Collinder objects Notes Errors There are some errors in Collinder's list or references to it. For example:Archinal, B. A., and S. J. Hynes. 2003. ''Star Clusters'', Richmond, VA: Willmann-Bell * Cr 21, NGC 956, 27, NGC 1746, 57, NGC 6738, 396, Collinder 399, 399, and Messier 73, 426 are asterism (astronomy), asterisms. * Cr 32, 33, and 34 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Cluster
An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and many more are thought to exist. Each one is loosely bound by mutual gravity, gravitational attraction and becomes disrupted by close encounters with other clusters and clouds of gas as they orbit the Galactic Center. This can result in a loss of cluster members through internal close encounters and a dispersion into the main body of the galaxy. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral galaxy, spiral and irregular galaxy, irregular galaxies, in which active star formatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellations were likely defined in prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, and mythology. Different cultures and countries invented their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. Naming constellations also helped astronomers and navigators identify stars more easily. Twelve (or thirteen) ancient constellations belong to the zodiac (straddling the ecliptic, which the Sun, Moon, and planets all traver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Hemisphere
In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer. If centered on the observer, half of the sphere would resemble a hemispherical screen over the observing location. The celestial sphere is a conceptual tool used in spherical astronomy to specify the position of an object in the sky without consideration of its linear distance from the observer. The celestial equator divides the celestial sphere into northern and southern hemispheres. Description Because astronomical objects are at such remote distances, casual observation of the sky offers no information on their actual distances. All celestial objects seem equally far away, as if fixed onto the inside of a sphere with a large but unknown radius, which appears to rotate westward over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pi Puppis
Pi Puppis, Latinisation of names, Latinized from π Puppis, also named Ahadi, is the List of stars in Puppis, second-brightest star in the southern constellation of Puppis. It has an apparent visual magnitude of about 2.7, so it can be viewed with the naked eye at night. Parallax measurements yield an estimated distance of roughly from the Earth. This is a double star with a magnitude 6.86 companion at an angular separation of 0.72 Minute and second of arc#Symbols and abbreviations, arcsecond and a position angle of 148° from the brighter primary. The stellar spectrum, spectrum of Pi Puppis matches a stellar classification of K3 Ib. The Ib luminosity class indicates this a lower luminosity supergiant star that has consumed the hydrogen fuel at its core, stellar evolution, evolved away from the main sequence, and expanded to about 235 times the solar radius, Sun's radius. The effective temperature of the star's outer envelope is approximately , which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Supergiant
Red supergiants (RSGs) are stars with a supergiant luminosity class ( Yerkes class I) and a stellar classification K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous. Betelgeuse and Antares A are the brightest and best known red supergiants (RSGs), indeed the only first magnitude red supergiant stars. Classification Stars are classified as supergiants on the basis of their spectral luminosity class. This system uses certain diagnostic spectral lines to estimate the surface gravity of a star, hence determining its size relative to its mass. Larger stars are more luminous at a given temperature and can now be grouped into bands of differing luminosity. The luminosity differences between stars are most apparent at low temperatures, where giant stars are much brighter than main-sequence stars. Supergiants have the lowest surface gravities and hence are the largest and brightest at a particular temperature. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Magnitude
Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Roman astronomer Claudius Ptolemy, whose star catalog popularized the system by listing stars from 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Pogson in 1856. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. A difference of 1.0 in magnitude corresponds to the brightness ratio of \sqrt /math>, or about 2.512. For example, a magnitude 2.0 star is 2. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Star
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: * ''Intrinsic variables'', whose luminosity actually changes periodically; for example, because the star swells and shrinks. * ''Extrinsic variables'', whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star has an orbiting companion that sometimes eclipses it. Many, possibly most, stars exhibit at least some oscillation in luminosity: the energy output of the Sun, for example, varies by about 0.1% over an 11-year solar cycle. Discovery An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago may be the oldest preserved historical document of the discovery of a variable star, the eclipsing binary Algol. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NV Puppis
NV Puppis (NV Pup), also known as υ1 Puppis, is a class B2V (blue main-sequence) star in the constellation Puppis. Its apparent magnitude is 4.67 and it is approximately 800 light years away based on parallax. It is a γ Cas variable, ranging from 4.78 to 4.58 magnitude. It is most likely an optical double with the nearby NW Puppis. Neither component of this double is given a letter in Lacaille's catalogue or the British Association The British Science Association (BSA) is a charity and learned society founded in 1831 to aid in the promotion and development of science. Until 2009 it was known as the British Association for the Advancement of Science (BA). The current Chief ... star catalogue. Gould gave them the designations (Latin letter) v1 and v2 Puppis, but these are rarely used. Lacaille applied the Greek letter υ to the star now called υ Carinae. The designation υ1 first appeared in several catalogues at the end of the 19th century. References { ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Cassiopeiae Variable
A Gamma Cassiopeiae variable (γ Cassiopeiae variable) is a type of variable star, named for its prototype γ Cassiopeiae. Variability γ Cassiopeiae variables show irregular changes in brightness on a timescale of decades. These typically have amplitudes of the order of a magnitude. For example, γ Cassiopeiae is usually about magnitude 2.5 and has varied between magnitudes 1.6 and 3.0. The variations are associated with changes in the spectrum between normal absorption spectra and Be star spectra, often also including shell star characteristics. Pleione and γ Cassiopeiae itself are both variable stars that have intermittent shell episodes where strong shell features appear in the spectrum and the brightness increases or decreases significantly. At other times the shell is not detectable in the spectrum, and even the emission lines may disappear. The General Catalogue of Variable Stars (GCVS) categorises γ Cassiopeiae stars as eruptive variables and describes them as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
