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Astronomy Magazine Special Issue
γ ι ζ γ δ α κ β κ ε γ β ρ ε ζ υ α φ ψ ω χ α π χ φ γ ω ο ι δ κ α ξ υ λ τ μ β α σ θ ε β σ δ γ ψ λ ω σ η ν θ Aι must-have for all stargazers η δ μ NEW EDITION! ζ λ β ε η κ NGC 6664 NGC 6539 ε τ μ NGC 6712 α υ δ ζ M26 ν NGC 6649 ψ Struve 2325 ζ ξ ATLAS χ α NGC 6604 ξ ο ν ν SCUTUM M16 of the γ SERP β NGC 6605 γ V450 ξ η υ η NGC 6645 M17 φ θ M18 ζ ρ ρ1 π Barnard 92 ο χ σ M25 M24 STARS M23 ν β κ All-in-one introduction ALL NEW MAPS WITH: to the night sky 42,000 more stars (87,000 plotted down to magnitude 8.5) AND 150+ more deep-sky objects (more than 1,200 total) The Eagle Nebula (M16) combines a dark nebula and a star cluster. In 100+ this intense region of star formation, “pillars” form at the boundaries spectacular between hot and cold gas. You’ll find this object on Map 14, a celestial portion of which lies above. photos PLUS: How to observe star clusters, nebulae, and galaxies AS2-CV0610.indd 1 6/10/10 4:17 PM NEW EDITION! AtlAs Tour the night sky of the The staff of Astronomy magazine decided to This atlas presents produce its first star atlas in 2006. -
A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short). -
2014 Observers Challenge List
2014 TMSP Observer's Challenge Atlas page #s # Object Object Type Common Name RA, DEC Const Mag Mag.2 Size Sep. U2000 PSA 18h31m25s 1 IC 1287 Bright Nebula Scutum 20'.0 295 67 -10°47'45" 18h31m25s SAO 161569 Double Star 5.77 9.31 12.3” -10°47'45" Near center of IC 1287 18h33m28s NGC 6649 Open Cluster 8.9m Integrated 5' -10°24'10" Can be seen in 3/4d FOV with above. Brightest star is 13.2m. Approx 50 stars visible in Binos 18h28m 2 NGC 6633 Open Cluster Ophiuchus 4.6m integrated 27' 205 65 Visible in Binos and is about the size of a full Moon, brightest star is 7.6m +06°34' 17h46m18s 2x diameter of a full Moon. Try to view this cluster with your naked eye, binos, and a small scope. 3 IC 4665 Open Cluster Ophiuchus 4.2m Integrated 60' 203 65 +05º 43' Also check out “Tweedle-dee and Tweedle-dum to the east (IC 4756 and NGC 6633) A loose open cluster with a faint concentration of stars in a rich field, contains about 15-20 stars. 19h53m27s Brightest star is 9.8m, 5 stars 9-11m, remainder about 12-13m. This is a challenge obJect to 4 Harvard 20 Open Cluster Sagitta 7.7m integrated 6' 162 64 +18°19'12" improve your observation skills. Can you locate the miniature coathanger close by at 19h 37m 27s +19d? Constellation star Corona 5 Corona Borealis 55 Trace the 7 stars making up this constellation, observe and list the colors of each star asterism Borealis 15H 32' 55” Theta Corona Borealis Double Star 4.2m 6.6m .97” 55 Theta requires about 200x +31° 21' 32” The direction our Sun travels in our galaxy. -
7.5 X 11.5.Threelines.P65
Cambridge University Press 978-0-521-19267-5 - Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer’s New General Catalogue Wolfgang Steinicke Index More information Name index The dates of birth and death, if available, for all 545 people (astronomers, telescope makers etc.) listed here are given. The data are mainly taken from the standard work Biographischer Index der Astronomie (Dick, Brüggenthies 2005). Some information has been added by the author (this especially concerns living twentieth-century astronomers). Members of the families of Dreyer, Lord Rosse and other astronomers (as mentioned in the text) are not listed. For obituaries see the references; compare also the compilations presented by Newcomb–Engelmann (Kempf 1911), Mädler (1873), Bode (1813) and Rudolf Wolf (1890). Markings: bold = portrait; underline = short biography. Abbe, Cleveland (1838–1916), 222–23, As-Sufi, Abd-al-Rahman (903–986), 164, 183, 229, 256, 271, 295, 338–42, 466 15–16, 167, 441–42, 446, 449–50, 455, 344, 346, 348, 360, 364, 367, 369, 393, Abell, George Ogden (1927–1983), 47, 475, 516 395, 395, 396–404, 406, 410, 415, 248 Austin, Edward P. (1843–1906), 6, 82, 423–24, 436, 441, 446, 448, 450, 455, Abbott, Francis Preserved (1799–1883), 335, 337, 446, 450 458–59, 461–63, 470, 477, 481, 483, 517–19 Auwers, Georg Friedrich Julius Arthur v. 505–11, 513–14, 517, 520, 526, 533, Abney, William (1843–1920), 360 (1838–1915), 7, 10, 12, 14–15, 26–27, 540–42, 548–61 Adams, John Couch (1819–1892), 122, 47, 50–51, 61, 65, 68–69, 88, 92–93, -
Making a Sky Atlas
Appendix A Making a Sky Atlas Although a number of very advanced sky atlases are now available in print, none is likely to be ideal for any given task. Published atlases will probably have too few or too many guide stars, too few or too many deep-sky objects plotted in them, wrong- size charts, etc. I found that with MegaStar I could design and make, specifically for my survey, a “just right” personalized atlas. My atlas consists of 108 charts, each about twenty square degrees in size, with guide stars down to magnitude 8.9. I used only the northernmost 78 charts, since I observed the sky only down to –35°. On the charts I plotted only the objects I wanted to observe. In addition I made enlargements of small, overcrowded areas (“quad charts”) as well as separate large-scale charts for the Virgo Galaxy Cluster, the latter with guide stars down to magnitude 11.4. I put the charts in plastic sheet protectors in a three-ring binder, taking them out and plac- ing them on my telescope mount’s clipboard as needed. To find an object I would use the 35 mm finder (except in the Virgo Cluster, where I used the 60 mm as the finder) to point the ensemble of telescopes at the indicated spot among the guide stars. If the object was not seen in the 35 mm, as it usually was not, I would then look in the larger telescopes. If the object was not immediately visible even in the primary telescope – a not uncommon occur- rence due to inexact initial pointing – I would then scan around for it. -
Probing Cosmic Ray Production in Massive Open Star Clusters with Three Years of Icecube Data
33RD INTERNATIONAL COSMIC RAY CONFERENCE, RIO DE JANEIRO 2013 THE ASTROPARTICLE PHYSICS CONFERENCE Probing cosmic ray production in massive open star clusters with three years of IceCube data THE ICECUBE COLLABORATION1. 1 See special section in these proceedings [email protected] Abstract: The ejecta of supernovae are the leading candidate sources of Galactic cosmic rays (CRs). Most Galactic supernovae are formed by the core-collapse of young massive stars that are clustered in regions of massive star formation. The combination of strong winds of the progenitors and the supernova ejecta leads to the formation of shocks where charged particles can be accelerated via diffusive shock acceleration. Neutrinos are a by-product of CR interactions in these clusters or their environment and can help to identify the sources of CRs. In this paper we study the sensitivity of IceCube to identify this spatially extended neutrino emission from massive open star clusters. Corresponding authors: S. Odrowski1, Y. Sestayo2, 1 Dept. of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2E1 2 T.U. Munich, D-85748 Garching, Germany Keywords: IceCube, cosmic rays, massive open clusters 1 Introduction sensitivity of the detector. IceCube achieves the highest Massive stars are the major contributors to the chemical en- sensitivity to TeV-PeV neutrino sources in the northern richment of the interstellar medium (ISM), restoring most hemisphere, a feature which is advantageous to study local of their total mass to the ISM through stellar winds and su- sources of neutrinos. The Sun is located in what is called pernova explosions, after processing a fraction of it in the the Local arm, a minor spiral feature of the Milky Way be- tween the Perseus and Sagittarius arms, which can be ac- stellar interior [1]. -
Charles Messier (1730-1817) Was an Observational Astronomer Working
Charles Messier (1730-1817) was an observational Catalogue (NGC) which was being compiled at the same astronomer working from Paris in the eighteenth century. time as Messier's observations but using much larger tele He discovered between 15 and 21 comets and observed scopes, probably explains its modern popularity. It is a many more. During his observations he encountered neb challenging but achievable task for most amateur astron ulous objects that were not comets. Some of these objects omers to observe all the Messier objects. At «star parties" were his own discoveries, while others had been known and within astronomy clubs, going for the maximum before. In 1774 he published a list of 45 of these nebulous number of Messier objects observed is a popular competi objects. His purpose in publishing the list was so that tion. Indeed at some times of the year it is just about poss other comet-hunters should not confuse the nebulae with ible to observe most of them in a single night. comets. Over the following decades he published supple Messier observed from Paris and therefore the most ments which increased the number of objects in his cata southerly object in his list is M7 in Scorpius with a decli logue to 103 though objects M101 and M102 were in fact nation of -35°. He also missed several objects from his list the same. Later other astronomers added a replacement such as h and X Per and the Hyades which most observers for M102 and objects 104 to 110. It is now thought proba would feel should have been included. -
Asteca: Automated Stellar Cluster Analysis
A&A 576, A6 (2015) Astronomy DOI: 10.1051/0004-6361/201424946 & c ESO 2015 Astrophysics ASteCA: Automated Stellar Cluster Analysis G. I. Perren1;3, R. A. Vázquez1;3, and A. E. Piatti2;3 1 Facultad de Ciencias Astronómicas y Geofísicas (UNLP), IALP-CONICET, La Plata, Argentina e-mail: [email protected] 2 Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, 5000 Córdoba, Argentina 3 Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina Received 6 September 2014 / Accepted 4 December 2014 ABSTRACT We present the Automated Stellar Cluster Analysis package (ASteCA), a suit of tools designed to fully automate the standard tests applied on stellar clusters to determine their basic parameters. The set of functions included in the code make use of positional and photometric data to obtain precise and objective values for a given cluster’s center coordinates, radius, luminosity function and inte- grated color magnitude, as well as characterizing through a statistical estimator its probability of being a true physical cluster rather than a random overdensity of field stars. ASteCA incorporates a Bayesian field star decontamination algorithm capable of assigning membership probabilities using photometric data alone. An isochrone fitting process based on the generation of synthetic clusters from theoretical isochrones and selection of the best fit through a genetic algorithm is also present, which allows ASteCA to provide accurate estimates for a cluster’s metallicity, age, extinction and distance values along with its uncertainties. To validate the code we applied it on a large set of over 400 synthetic MASSCLEAN clusters with varying degrees of field star contami- nation as well as a smaller set of 20 observed Milky Way open clusters (Berkeley 7, Bochum 11, Czernik 26, Czernik 30, Haffner 11, Haffner 19, NGC 133, NGC 2236, NGC 2264, NGC 2324, NGC 2421, NGC 2627, NGC 6231, NGC 6383, NGC 6705, Ruprecht 1, Tombaugh 1, Trumpler 1, Trumpler 5 and Trumpler 14) studied in the literature. -
Survey of Emission Line Stars in Young Open Clusters
SurveySurvey ofof emissionemission lineline starsstars inin youngyoung openopen clustersclusters AnnapurniAnnapurni SubramaniamSubramaniam Collaborators: Blesson Mathew & B.C. Bhatt EmissionEmission lineline stars:stars: whatwhat areare they?they? These stars show H-alpha emission lines in their spectra – indication of circum-stellar material. Two classes: (1) remnant of the accretion disk – pre-Main sequence stars – Herbig Ae/Be stars (2) Classical Be stars – material thrown out of the star forming a disk. These stars are well studied in the field – not in clusters - uncertainty in estimating their distance, interstellar reddening, age, mass and evolutionary state. ClusterCluster stars:stars: advantageadvantage TheseThese starsstars locatedlocated inin clustersclusters helphelp toto estimateestimate theirtheir propertiesproperties accuratelyaccurately –– distance,distance, reddening,reddening, massmass (spectral(spectral type)type) andand age.age. ToTo studystudy thethe emissionemission phenomenonphenomenon asas aa functionfunction ofof stellarstellar propertiesproperties –– possiblepossible inin thethe casecase ofof clustersclusters stars.stars. PropertiesProperties ofof thethe circumcircum--stellarstellar diskdisk cancan bebe studiedstudied asas aa functionfunction ofof massmass andand age.age. LargeLarge numbernumber ofof starsstars cancan bebe identifiedidentified toto havehave aa largelarge sample,sample, willwill helphelp toto studystudy andand classifyclassify themthem intointo variousvarious groups.groups. DataData Aim: -
Cassiopeia a Monthly Sky Guide for the Beginning to Intermediate Amateur Astronomer Tom Trusock 06-Nov-2005
Small Wonders: Cassiopeia A monthly sky guide for the beginning to intermediate amateur astronomer Tom Trusock 06-Nov-2005 Figure 1. W idefield map 2/15 Small Wonders: Cassiopeia Target List Object Type Size Mag RA Dec h m s α (alpha) Cassiopeiae (Schedar) Star 2.2 00 40 51.2 +56° 34' 23" h m s η (eta) Cassiopeiae (Achird) Star 3.5 00 49 26.6 +57° 51' 07" M 52 Open Cluster 16.0' 6.9 23h 25m 06.5s +61° 38' 33" NGC 7788 Open Cluster 4.0' 9.4 23h 57m 00.3s +61° 26' 11" NGC 7789 Open Cluster 25.0' 6.7 23h 57m 42.3s +56° 44' 41" NGC 7790 Open Cluster 5.0' 8.5 23h 58m 42.6s +61° 14' 41" NGC 147 Galaxy 13.2'x7.8' 9.4 00h 33m 31.5s +48° 32' 34" NGC 185 Galaxy 8.0'x7.0' 9.3 00h 39m 17.7s +48° 22' 22" NGC 281 Bright Nebula 35.0'x30.0' 00h 53m 20.8s +56° 39' 26" NGC 457 Open Cluster 20.0' 6.4 01h 19m 55.9s +58° 19' 29" M 103 Open Cluster 6.0' 7.4 01h 33m 46.3s +60° 41' 28" NGC 654 Open Cluster 6.0' 6.5 01h 44m 25.0s +61° 54' 54" NGC 659 Open Cluster 6.0' 7.9 01h 44m 48.2s +60° 42' 05" NGC 663 Open Cluster 15.0' 7.1 01h 46m 41.6s +61° 14' 56" Challenge Objects Object Type Size Mag RA Dec IC 10 Galaxy 6.4'x5.3' 11.2 00h 20m 44.3s +59° 19' 43" Maffei 1 Galaxy 5.0'x3.0' 11.4 02h 36m 45.8s +59° 40' 40" Cassiopeia t‘s time to pay homage to the Queen. -
Age Determinations of Open Star Clusters King 14 & NGC
AGE DETERMINATIONS OF THE OPEN STAR CLUSTERS KING 14 AND NGC 146 V. Kopchev, P. Nedialkov*, G. Petrov Abstract We based on 2MASS J and Ks photometry for the open star clusters King 14 and NGC 146, and using color magnitude diagrams with isochrones fit we have found an age of log(age) = 7.8 (63 8 Myr) for King 14 and log(age) = 7.5 (32 8 Myr) for NGC 146. Our age determination is bigger than given in Lynga [5] ( log(age) = 7.2 for King 14 and log(age) = 7.1 for NGC 146 ) and less than Dias [6] ( log(age) = 7.9 for King 14 and log(age) = 7.8 for NGC 146 ). Key words: star cluster, age determinations Introduction. Open star clusters are physically related groups of stars held together by mutual gravitational attraction. Therefore, they populate a limited region of space, typically much smaller than their distance from us, so that they are all roughly at the same distance. They are believed to originate from large cosmic gas and dust clouds in the Milky Way, and to continue to orbit the galaxy through the disk. Over 1600 open clusters are known in our Galaxy, and this is probably only a small percentage of the total population which is probably some factor higher, estimates of as many as about 100 000 Milky Way open clusters have been given. Most open clusters are young, generally less than a few hundred million years old. They are rich in the youngest and most heavy element-rich stars. Open clusters are very important objects in the study of stellar evolution, because the stars are all of very similar age and chemical composition, the effects of other more subtle variables on the properties of stars are much more easily studied than they are for isolated stars. -
New Catalogue of Blue Stragglers in Open Clusters
A&A 463, 789–797 (2007) Astronomy DOI: 10.1051/0004-6361:20054590 & c ESO 2007 Astrophysics New catalogue of blue stragglers in open clusters J. A. Ahumada and E. Lapasset Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, 5000 Córdoba, Argentina e-mail: [javier;lapasset]@oac.uncor.edu Received 25 November 2005 / Accepted 26 September 2006 ABSTRACT We present a catalogue of blue-straggler candidates in galactic open clusters. It is based on the inspection of the colour–magnitude diagrams of the clusters, and it updates and supersedes the first version (Ahumada & Lapasset 1995). A new bibliographical search was made for each cluster, and the resulting information is organised into two tables. Some methodological aspects have been revised, in particular those concerning the delimitation of the area in the diagrams where the stragglers are selected. A total of 1887 blue-straggler candidates have been found in 427 open clusters of all ages, doubling the original number. The catalogued stars are classified into two categories mainly according to membership information. Key words. catalogs – open clusters and associations: general – stars: blue stragglers 1. Introduction seven field stragglers. Two-thirds out of a group of sixty-two low-metallicity stars are binaries, of which about half may be Blue stragglers are stars that seem to stay on the main sequence blue stragglers (Preston & Sneden 2000). These could have re- longer than is estimated by the standard theory of stellar evolu- sulted from mass transfer events; in globular clusters, this kind tion. They have been identified in star clusters, dwarf galaxies, of long-period binaries would not have survived.