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| | COMA BERENICES |
 | | The stars belonging to a cluster have a common proper motion (a shift that is discovered by photographing one and the same sky area in different moments of time) relative to other stars. | | | Astronomrs do it by comparing the stellar magnitude of a star observed through a blue filter and denoted by B, with the magnitude obtained through a yellow-green filter and denoted by V. The value B - V is called a colour index. | | | The stellar magnitude measures the apparent brightness of the star which depends on its luminosity and its distance to us. |
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http://www.eso.org/outreach/eduoff/edu-prog/catchastar/CAS2002/cas-projects/bulgaria_comaber_1
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| | Pleiades (star cluster) - Wikipedia, the free encyclopedia |
| | Ages for star clusters can be estimated by comparing the H-R diagram for the cluster with theoretical models of stellar evolution, and using this technique, ages for the Pleiades of between 75 and 150 million years have been estimated. | | | Another way of estimating the age of the cluster is by looking at the lowest-mass objects. | | | Green squares indicate the seven optically brightest stars. |
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http://www.wikipedia.org/wiki/Pleiades_%28star_cluster%29
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| | ASP: Editorial: The Border |
| | The unintentional inclusion of non-cluster stars in the analysis leads to errors. | | | The "halo" stars originated with the rest of the Hyades stars when the cluster was born but have gradually moved away from the central regions and are no longer bound to the cluster. | | | Thus, the Hyades star cluster is a fundamental stepping stone in our path to deriving distances to stars and galaxies, and ultimately, to determining the size and age of the universe. |
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http://www.astrosociety.org/pubs/mercury/9803/hyades.html
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| | Hyades |
| | Star clusters are crucial for understanding the lives of the stars everywhere, because all the members of a cluster formed at the same time from the same raw materials. | | | The cluster has done well to survive so long.The individual stars of the Hyades are bound together by the gravity of the cluster as a whole, and their collective and individual motions are also plotted by Hipparcos. | | | The distance to the centre of the Hyades cluster is 151 light-years (46.34 parsecs) with an uncertainty of less than one light-year (0.27 parsec). |
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http://www.xs4all.nl/~carlkop/hyades.html
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| | Extrasolar Planets |
| | Stevens, and others (7) on the other hand, speculate on planet formation from a binary star system in which one of the stars is a neutron star (pulsar). | | | CM-Draconis, it is worth considering, because of the research program focused on this star and the use of the astronomical technique known as occultation. | | | Beta Pictoris is a star belonging to A5V spectral class, it has a visual magnitude of 3.85, and is approximately 17.17 parsecs (58.68 light years) from Earth. |
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http://www.public.asu.edu/~sciref/exoplnt.htm
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| | pubobj.txt |
| | Ptolemy III was king of Egypt from 246 to 221 B.C. Coma Star Cluster RA 12hr 25min Dec +26 00 Mag 1.8 Size 6 deg This large scattered star grouping is best studied in a pair of binoculars or a finderscope. | | | The Sun would be a magnitude 18 star and only visible in the very largest amateur telescopes. | | | A very nice double star, the members are 2 and 5 magnitude separated by 10". |
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http://www.stargazing.net/BerkeleyAstro/images/pubobj.txt
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| | Distance to Hyades Cluster |
| | PPM proper motions and the cluster center proper motion derived from Schwan (1991), as the three stars were either too bright for accurate measurement in the study of Hanson (1975) or were outside his field of view. | | | According to equation (1), after scaling due to differing angular distances from the convergent point, the distance of a star relative to the cluster center is given by the ratio of the star's proper motion to that of the cluster center. | | | Since the target stars were about 4 mag brighter than the reference stars, we have searched for a possible systematic error as a function of star brightness, the magnitude equation. |
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http://ecf.hq.eso.org/~ralbrech/sepdec97apjl/5359.html
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| | star - Columbia Encyclopedia article about star |
| | In 1650 Riccioli made the first binary system discovery, that of the middle star in the Big Dipper's handle, Zeta Urase Majoris. | | | applies the laws of physics to calculation of the equilibrium configurations of stars. | | | From the observed proper motion proper motion, in astronomy, apparent movement of a star on the celestial sphere, usually measured as seconds of arc per year; it is due both to the actual relative motions of the sun and the star through space. |
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http://columbia.thefreedictionary.com/STAR
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| | 86.html |
| | As a continuing part of the goals of the CFHT Open Star Cluster Survey to better understand dynamical processes of open clusters, we also fit a King model to the cluster density distribution and investigate the cluster main-sequence luminosity and mass functions in increasing concentric annuli. | | | Abstract: We present deep CCD photometry of the very rich, intermediate-age (similar to the Hyades) open star cluster NGC 2099 (M37). | | | The CFH12K photometry for this cluster is faint enough (V~24.5) to detect the remnants of the most massive progenitor cluster stars under the Type I SNe limit. |
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http://www.astro.ubc.ca/people/richer/86.html
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| | Dark Matter |
| | Another method astronomers use to determine the mass of a galaxy (or cluster of galaxies) is simply to look at how much light there is. By measuring the amount of light reaching the earth, the scientists can estimate the number of stars in the galaxy. | | | And on top of that, the stars move at speeds that should rip the galaxy apart; there is not enough measured mass to supply the gravity needed to hold the galaxy together (7). | | | Stars like our sun form when a mass of hydrogen collapses under its own gravity and the intense pressure initiates a nuclear reaction, emitting light and energy. |
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http://www.eclipse.net/~cmmiller/DM/index.html
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| | Pleiades move with the times |
| | Atlas, one of the brightest stars in the cluster, is a binary, and by determining the orbital parameters with interferometry a precise distance can be calculated. | | | Nearby star clusters such as the Pleiades play an important role in stellar astronomy by providing groups of stars of the same age and distance from the Earth. | | | The Hipparcos satellite has mapped the positions of over 100,000 stars with much greater accuracy than was previously possible. |
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http://www.nature.com/nature/links/040122/040122-2.html
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| | Messier Object 45 |
| | Apparently surrounding Aldebaran is another, equally famous open cluster, the Hyades; Aldebaran is known to be a non-member foreground star (at 68 light years distance, compared to 150 ly for the Hyades). | | | More information can be found in our table of the main Pleiades stars and the corresponding nebulosity with the catalog numbers. | | | An Inquiry into the probable Parallax, and Magnitude, of the Fixed Stars, from the Quantity of Light which they afford us, and the particular Circumstances of their Situation. |
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http://www.seds.org/messier/m/m045.html
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| | Nebulae and Star Formation |
| | The proplyds which are closest to the hottest stars of the parent star cluster are seen as bright objects, while the object farthest from the hottest stars is seen as a dark object. | | | Other hot stars, also present in the nebula, are ionizing the extended optical nebulosity. | | | The massive stars in A1 and A2 must have formed within the last 10,000 years, since their natal gas shrouds are not yet disrupted by the powerful radiation of the newly born stars. |
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http://faculty.rmwc.edu/tmichalik/NebandStar.htm
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| | The Pleiades |
| | The figure at right, covering a somewhat larger area than the AAO photograph, shows the brightest stars in the vicinity, most of which are members of the Pleiades cluster (some appear in the same part of the sky but actually lie at a different distance). | | | Stars like our sun, of which there are a few in the cluster, appear as faint flecks of light in the AAO photograph at the top of this page, and are well below the sensitivity of the human eye. | | | All stars selected have magnitudes of 6.5 or brighter, which is about the limit of human vision under ideal conditions -- how many you actually see depends on your own eyesight, local atmospheric transparency, and light pollution levels. |
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http://www.ras.ucalgary.ca/~gibson/pleiades
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| | Nat' Academies Press, Failed Stars and Super Planets: A Report Based on the January 1998 Workshop on Substellar-Mass Objects (1998) |
| | The MF of brown dwarfs in clusters could be directly probed by looking for microlensing of background stars, but this approach has not yet been attempted.4 At present, young open clusters are the only systems where the mass function can be measured from low-mass stars across the hydrogen-burning limit into the brown-dwarf regime. | | | Crucial to understanding the distribution of ordinary matter in astronomical objects is the abundance of low-mass stars and substellar-mass objects, as most of the objects, if not most of the mass, is in this low-mass component. | | | Radial-velocity studies of field stars to measure the MF of secondaries in binary systems; and |
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http://books.nap.edu/books/NI000653/html/44.html
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| | taurus.html |
| | The brightest star in the cluster, Aldebaran, is not actually a cluster member... | | | The Hyades is a rather loose star cluster made up of around 100 member stars. | | | A supernova is the final stage in the life of a large star. |
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http://www.utahskies.org/deepsky/constellations/taurus.html
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| | Melotte 111 and M3 |
| | I immediately noticed that the Coma Star Cluster is way too big for the 15 x 80 with its 3.5-degree field of view. | | | The Coma Star Cluster was not visible with the naked eye. | | | Binocular Objects (4): Melotte 111 and M3 On April 11th 2004 I observed Melotte 111(Coma Star Cluster) and M 3 with the Skywindow and my 7x 50 Bresser and the Vixen 15 x 80 binoculars. |
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http://www.backyard-astro.com/deepsky/bino/04_b.html
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| | ASTR1000L-Lab10.doc |
| | A star cluster is a grouping of stars which formed in the same region of space and at the same time period. | | | In this lab we will plot the apparent magnitude of each star in the Hyades. | | | The use of absolute magnitude is a way to compare the intrinsic brightness of each star. |
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http://www.faculty.de.gcsu.edu/~domingue/ASTR1000L-Lab10.doc
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| | The Utah Skies Report |
| | Numerous young blue stars and star clusters, spawned by the galaxy collision, are seen in the spiral arms, as well as in the long "tidal" tail of stars. | | | Once formed, the star clusters become redder with age as the most massive and bluest stars exhaust their fuel and burn out. | | | While the stars are essentially motionless over short periods of time, solar system objects would appear to move. |
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http://www.utahskies.org/report/20020503/20020503weekly.html
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| | Notes: Hyades |
| | Measure the positions of a few Hyades stars on archival CCD images | | | Aim to gather at least two CCD images per Hyades star | | | Make observations of the Hyades stars as the weather permits, during the term and measure their current astrometric positions |
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http://www.dur.ac.uk/john.lucey/astrolab/hyades_notes.html
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| | sp200004.txt |
| | The cluster has about 30 stars and is also known by the catalog name "Melotte 111." The best way to see this cluster of stars -- which is as broad as ten full moons side-by-side -- is with a pair of wide field binoculars. | | | Virgo's brightest star is the first magnitude Spica. | | | Coma Berenices is lesser known than nearby Virgo and this is probably because she does not have any 1st magnitude stars and is not located along the Ecliptic, the Sun's yearly path, and thus lacks any astrological significance for the superstitious. |
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http://members.fortunecity.com/starpoints/2000/sp200004.txt
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| | JPL News -- Astronomers Measure Distance to Well-Known Star |
| | The star, along with "wife" Pleione and their daughters, the "seven sisters," are the principal stars of the Pleiades that are visible to the unaided eye, although there are actually thousands of stars in the cluster. | | | The cluster of stars known as the Pleiades is one of the most recognizable objects in the night sky, and for millennia has been celebrated in literature and legend. | | | The traditional method of measuring distance is by noting the precise position of a star and then measuring its slight change in position when Earth itself has moved to the other side of the sun. |
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http://www.jpl.nasa.gov/releases/2004/26.cfm
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| | 89.html |
| | Abstract: We present analysis of deep CCD photometry for the very rich, old open star cluster NGC 6819. | | | The CFHT Open Star Cluster Survey II -- Deep CCD Photometry of the Old Open Star Cluster NGC 6819 | | | These CFH12K data results represent the first of nineteen open star clusters which were imaged as a part of the CFHT Open Star Cluster Survey. |
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http://www.astro.ubc.ca/people/richer/89.html
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| | Catch A Star! - Hyades Project |
| | The cluster of stars surrounding Aldebaran are the Hyades. | | | Also, as all the stars in a cluster formed from the same diffuse nebula, they are all of similar initial chemical composition. | | | Because the stars in open clusters are formed in nearly the same time and they have similar chemical composition, the H-R diagram gives us important information about stellar evolution. |
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http://www.eso.org/outreach/eduoff/edu-prog/catchastar/CAS2002/cas-projects/bulgaria_hyades_1
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| | OpenClu.html |
| | To find the distance modulus on these H-R diagrams, keep your transparency lined up so that the main sequence matches the star data points in the cluster. | | | The nearest star cluster with a well populated main sequence, the Hyades Cluster in the constellation Taurus, is crucial to this technique. | | | A young cluster is a cluster whose stars have just begun to shine by burning hydrogen in their centers and therefore should have its stars on the main sequence. |
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http://www.astro.lsa.umich.edu/Course/MMSS/OpenClu.html
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| | MPIfR Publications 2002 |
| | Ikhsanov, N.R.: Supersonic propeller spindown of neutron stars in wind-fed mass-exchange close binaries. | | | Voß, H.: Modeling the star formation history of the universe to compare with mm and sub-mm deep field surveys. | | | Preibisch, T., Zinnecker, H.,Guenther, E.: Triggered Star Formation in the Sco OB2 Association (Invited)In:Modes of Star Formation and the Origin of Field Populations, ASP Conference Proceedings, Vol. |
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http://www.mpifr-bonn.mpg.de/staff/wsherwood/publications02.html
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| | Coma Berenice star cluster |
| | At a distance of 250 light years, the Coma star cluster is one of the nearest of all the open star clusters. | | | Although this beautiful star cluster was not included in the NGC or Messier catalogue, it should be on every (binocular) observing list, together with some other large open clusters like M45, The Hyades, and the Alpha Persei Moving Cluster. | | | The Coma Berenices Star Cluster is a large open cluster, covering an area of 5 degrees. |
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http://www.backyard-astro.com/focusonarchive/comaberenice/comaberenice.html
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| | Canberra Astronomical Society - Southern Cross - June 2005 |
| | Home to some of the thousands of galaxies that make up the great Coma-Virgo cluster (not to be confused with the Coma star cluster to which its naked-eye stars belong), Coma Berenices is primarily a hunting ground for faint fuzzies. | | | Binoculars show it elongated roughly east-west, the 5th magnitude binary star 35 Com sitting well within the field. | | | Struve 1633 - double star of magnitudes 7 each, separation 9 arcseconds. |
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http://msowww.anu.edu.au/cas/southerncross/sc_200506.html
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| | Mythology of the Seven Sisters (Pleiads) |
| | A possible alternate name is Asterië (`of the starry sky' or `of the sun'), which may also be a name for the creatrix of the universe, Eurynome, in the Pelasgian myth. | | | The Pleiad(e)s were the seven daughters of Atlas and Pleione, and half-sisters of the Hyades, whose mother was Æthra (`bright sky'; a different Æthra than the mother of Theseus). | | | The mythology associated with the Pleiades cluster is extensive; Burnham alone devotes eight pages to the subject, and Allen more than twice that number (see references). |
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http://www.ras.ucalgary.ca/%7Egibson/pleiades/pleiades_myth.html
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| | Pubblicazioni - Università di Bologna |
| | Sabbi, E.; Ferraro, F. Sills, A.; Rood, R. The small Blue Straggler star population in the dense Galactic Globular Cluster NGC 6752. | | | The X-Ray-derived Cosmological Star Formation History and the Galaxy X-Ray Luminosity Functions in the Chandra Deep Fields North and South. | | | The VIMOS VLT Deep Survey - The evolution of galaxy clustering to z=2.1 from first epoch observations. |
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http://www.astronomia.unibo.it/Astronomia/Ricerca/Pubblicazioni
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