Open Clusters
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![Arxiv:2012.09981V1 [Astro-Ph.SR] 17 Dec 2020 2 O](https://docslib.b-cdn.net/cover/3257/arxiv-2012-09981v1-astro-ph-sr-17-dec-2020-2-o-73257.webp)
Arxiv:2012.09981V1 [Astro-Ph.SR] 17 Dec 2020 2 O
Contrib. Astron. Obs. Skalnat´ePleso XX, 1 { 20, (2020) DOI: to be assigned later Flare stars in nearby Galactic open clusters based on TESS data Olga Maryeva1;2, Kamil Bicz3, Caiyun Xia4, Martina Baratella5, Patrik Cechvalaˇ 6 and Krisztian Vida7 1 Astronomical Institute of the Czech Academy of Sciences 251 65 Ondˇrejov,The Czech Republic(E-mail: [email protected]) 2 Lomonosov Moscow State University, Sternberg Astronomical Institute, Universitetsky pr. 13, 119234, Moscow, Russia 3 Astronomical Institute, University of Wroc law, Kopernika 11, 51-622 Wroc law, Poland 4 Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University, Kotl´aˇrsk´a2, 611 37 Brno, Czech Republic 5 Dipartimento di Fisica e Astronomia Galileo Galilei, Vicolo Osservatorio 3, 35122, Padova, Italy, (E-mail: [email protected]) 6 Department of Astronomy, Physics of the Earth and Meteorology, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynsk´adolina F-2, 842 48 Bratislava, Slovakia 7 Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, H-1121 Budapest, Konkoly Thege Mikl´os´ut15-17, Hungary Received: September ??, 2020; Accepted: ????????? ??, 2020 Abstract. The study is devoted to search for flare stars among confirmed members of Galactic open clusters using high-cadence photometry from TESS mission. We analyzed 957 high-cadence light curves of members from 136 open clusters. As a result, 56 flare stars were found, among them 8 hot B-A type ob- jects. Of all flares, 63 % were detected in sample of cool stars (Teff < 5000 K), and 29 % { in stars of spectral type G, while 23 % in K-type stars and ap- proximately 34% of all detected flares are in M-type stars. -
Open Cluster NGC 188 Explored with Astrosat 9 December 2020, by Tomasz Nowakowski
Open cluster NGC 188 explored with AstroSat 9 December 2020, by Tomasz Nowakowski Discovered in 1825, NGC 188 is an open cluster in the constellation Cepheus, located some 5,400 light years away from the Earth. It has a solar metallicity, a radius of about 11.8 light years, reddening at a level of 0.036, and its age is estimated to be 7 billion years. It is one of the oldest and well studied OCs in our galaxy. In order to learn more about the member stars of NGC 188, a team of astronomers led by Sharmila Rani of the Indian Institute of Astrophysics in Bengaluru, India, has performed a photometric study of this cluster with the main goal of identifying its ultraviolet-bright stars. For this purpose, they used AstroSat's Ultraviolet Imaging Telescope (UVIT). "In this study, we present the results of the UV UVIT image of NGC 188 obtained by combining images imaging of the NGC 188 in two FUV [far-ultraviolet] in NUV (N279N) and FUV (F148W) channels. Yellow and one NUV [near-ultraviolet] ?lters using UVIT on and blue color corresponds to NUV and FUV detections, AstroSat. We characterize the UV bright stars respectively. Credit: Rani et al., 2020. identi?ed in this cluster by analysing SEDs [spectral energy distributions] to throw light on their formation and evolution," the astronomers wrote in the paper. Indian researchers have carried out ultraviolet photometric observations of an old open cluster FUV observations detected hot and bright blue known as NGC 188. Results of the study, straggler stars (BSSs), one hot subdwarf, and one conducted with the AstroSat spacecraft, provide white dwarf candidate. -
Winter Constellations
Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the Orion Nebula. -
![Arxiv:1606.06587V1 [Astro-Ph.SR] 21 Jun 2016 Rpitsbitdt Elsevier to Submitted Preprint Sn MS Aao.W Bandtecutrsdsac Fro Distance Cluster’S the Obtained We Catalog](https://docslib.b-cdn.net/cover/6305/arxiv-1606-06587v1-astro-ph-sr-21-jun-2016-rpitsbitdt-elsevier-to-submitted-preprint-sn-ms-aao-w-bandtecutrsdsac-fro-distance-cluster-s-the-obtained-we-catalog-196305.webp)
Arxiv:1606.06587V1 [Astro-Ph.SR] 21 Jun 2016 Rpitsbitdt Elsevier to Submitted Preprint Sn MS Aao.W Bandtecutrsdsac Fro Distance Cluster’S the Obtained We Catalog
2MASS photometry and kinematical studies of open cluster NGC 188 W. H. Elsanhourya,b1, A. A. Haroona,c, N. V. Chupinad, S. V. Vereshchagind, Devesh P. Sariyae2, R. K. S. Yadav f , Ing-Guey Jiange aAstronomy Department, National Research Institute of Astronomy and Geophysics (NRIAG) 11421, Helwan, Cairo, Egypt bPhysics Department, Faculty of Science, Northern Border University, Rafha Branch, Saudi Arabia cAstronomy Department, Faculty of Science, King Abdul Aziz University, Jeddah, Saudi Arabia dInstitute of Astronomy Russian Academy of Sciences (INASAN),48 Pyatnitskaya st., Moscow, Russia eDepartment of Physics and Institute of Astronomy, National Tsing Hua University, Hsin-Chu, Taiwan f Aryabhatta Research Institute of observational sciencES (ARIES), Manora Peak Nainital 263 002, India. Abstract In this paper, we present our results for the photometric and kinematical studies of old open cluster NGC 188. We determined various astrophysical parameters like limited radius, core and tidal radii, distance, luminosity and mass functions, total mass, relaxation time etc. for the cluster using 2MASS catalog. We obtained the cluster’s distance from the Sun as 1721 41 pc and log (age)= 9.85 0.05 at Solar metallicity. The relaxation time of the cluster is smaller± than the estimated cluster± age which suggests that the cluster is dynamically relaxed. Our results agree with the values mentioned in the literature. We also determined the clusters apex coordinates as (281◦.88, 44◦.76) using AD-diagram method. Other kinematical parameters like space velocity components,− cluster center and elements of Solar motion etc. have also been computed. Keywords: Open clusters- Color-magnitude diagram- Kinematics- AD diagram 1. -
Wynyard Planetarium & Observatory a Autumn Observing Notes
Wynyard Planetarium & Observatory A Autumn Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn Tour of the Sky with the Naked Eye CASSIOPEIA Look for the ‘W’ 4 shape 3 Polaris URSA MINOR Notice how the constellations swing around Polaris during the night Pherkad Kochab Is Kochab orange compared 2 to Polaris? Pointers Is Dubhe Dubhe yellowish compared to Merak? 1 Merak THE PLOUGH Figure 1: Sketch of the northern sky in autumn. © Rob Peeling, CaDAS, 2007 version 1.2 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. Close to the horizon is a group of stars like the outline of a saucepan with the handle stretching to your left. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The two right-hand stars are called the Pointers. Can you tell that the higher of the two, Dubhe is slightly yellowish compared to the lower, Merak? Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white- hot. 2. Use the Pointers to guide you upwards to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the left are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris. -
Institute of Theoretical Physics and Astronomy, Vilnius University
INSTITUTE OF THEORETICAL PHYSICS AND ASTRONOMY, VILNIUS UNIVERSITY Justas Zdanaviˇcius INTERSTELLAR EXTINCTION IN THE DIRECTION OF THE CAMELOPARDALIS DARK CLOUDS Doctoral dissertation Physical sciences, physics (02 P), astronomy, space research, cosmic chemistry (P 520) Vilnius, 2006 Disertacija rengta 1995 - 2005 metais Vilniaus universiteto Teorin˙es fizikos ir astronomijos institute Disertacija ginama eksternu Mokslinis konsultantas prof.habil.dr. V. Straiˇzys (Vilniaus universiteto Teorin˙es fizikos ir astronomijos institutas, fiziniai mokslai, fizika – 02 P) VILNIAUS UNIVERSITETO TEORINES˙ FIZIKOS IR ASTRONOMIJOS INSTITUTAS Justas Zdanaviˇcius TARPZVAIGˇ ZDINˇ EEKSTINKCIJA˙ ZIRAFOSˇ TAMSIU¸JU¸ DEBESU¸KRYPTIMI Daktaro disertacija Fiziniai mokslai, fizika (02 P), astronomija, erdv˙es tyrimai, kosmin˙e chemija (P 520) Vilnius, 2006 CONTENTS PUBLICATIONONTHESUBJECTOFTHEDISSERTATION .....................5 1. INTRODUCTION ................................................................6 2. REVIEWOFTHELITERATURE ................................................8 2.1. InvestigationsoftheinterstellarextinctioninCamelopardalis ..................8 2.2. Distinctiveobjectsinthearea ................................................10 2.3. Extinctionlawintheinvestigatedarea .......................................11 2.4. Galacticmodelsandluminosityfunctions .....................................11 2.5. SpiralstructureoftheGalaxyintheinvestigateddirection ...................12 3. METHODS ......................................................................14 -
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. -
TAAS Monthly Observing Challenge December 2015 Deep Sky Object
TAAS Monthly Observing Challenge December 2015 Deep Sky Object NGC 772 (GX) Aries ra: 01h 59m 20.1s dec: +19° 00’ 26” Magnitude (visual) = 10.3 Size = 7.2’ x 4.3’ Position angle = 130° Description: NGC 772 (also known as Arp 78) is an unbarred spiral galaxy approximately 130 million light-years away in the constellation Aries. Around 200,000 light years in diameter, NGC 772 is twice the size of the Milky Way Galaxy, and is surrounded by several satellite galaxies – including the dwarf elliptical, NGC 770 – whose tidal forces on the larger galaxy have likely caused the emergence of a single elongated outer spiral arm that is much more developed than the others arms. Halton Arp includes NGC 772 in his Atlas of Peculiar Galaxies as Arp 78, where it is described as a "Spiral galaxy with a small high-surface brightness companion". Two supernovae (SN 2003 hl & SN 2003 iq) have been observed in NGC 772. Source: https://www.wikipedia.org/wiki/NGC_772 AL: Herschel 400 Challenge Object NGC 2371 / 2372 (PN) Gemini ra: 07h 25m 34.8s dec: +29° 29’ 22” Magnitude (visual) = 11.2 Size = 62” Description: NGC 2371-2 is a dual lobed planetary nebula located in the constellation Gemini. Visually, it appears like it could be two separate objects; therefore, two entries were given to the planetary nebula by William Herschel in the "New General Catalogue", so it may be referred to as NGC 2371, NGC 2372, or variations on this name. Source: https://www.wikipedia.org/wiki/NGC_2371-2 AL: Herschel 400, Planetary Nebula Binocular Object NGC 1807 (OC) Taurus ra: 05h 10m 46.0s dec: +16° 31’ 00” Magnitude (visual) = 7.0 Size = 12’ Description: NGC 1807 is an open cluster at the border of the constellations Taurus and Orion near the open cluster NGC 1817. -
Preliminary Catalogue of Isaac Roberts's Collection of Photographs of Celestial Objects
ASTRONOMISCHE NACHRICHTEN. Nr. 4154. Band 174. 2. Preliminary catalogue of Isaac Roberts’s collection of photographs of celestial objects. By Dorotha Isaac-Roberts. The Isaac Roberts collection of celestial photographs The number of the copies of the forthcoming paper comprises 2485 original negatives of stars, star-clusters, being very limited, the observatories and astronomers, official nebulae and other celestial objects together with many posi. or amateur, who are specially interested in photographic tives on glass and on paper, taken by the late Dr. Isaac astronomy will please send in their names to the address Roberts or, under his incessant supervision, by his assistant given below, early in 1907, in order that the various parts W. S. Franks, F. R. A. S., at Dr. Roberts’s Private Obser- of the complete catalogue may be sent to them in course vatory, Kennessee, Maghull, near Liverpool (1885-1 890) and, of time. from 1890 to 1904, at Starfield, Crowborough, Sussex. Positives- on-glass reproduced from the Isaac Roberts Of the above mentioned negatives, negatives will be lent for the purpose of micrometric mea- I) 1412 were taken with the zo-in Reflector (focal surements, if, application be made and provided that the length = 98.0 ins) and with an exposure of the plate of documents be returned after completion of the measurements. ninety minutes in general. In the preliminary catalogue given below, the numbers 2) 648 with the 5-in Cooke lens (f. 1. = 19.22 ins) of Dr. Dreyer’s New General Catalogue of Nebulae and which was mounted on the tube of the zo-in Reflector; or, Clusters of Stars and of Dr. -
Open Clusters in Gaia
Sede Amministrativa: Università degli Studi di Padova Dipartimento di Fisica e Astronomia “G. Galilei” Corso di Dottorato di Ricerca in Astronomia Ciclo XXX OPEN CLUSTERS IN GAIA ERA Coordinatore: Ch.mo Prof. Giampaolo Piotto Supervisore: Dr.ssa Antonella Vallenari Dottorando: Francesco Pensabene i Abstract Context. Open clusters (OCs) are optimal tracers of the Milky Way disc. They are observed at every distance from the Galactic center and their ages cover the entire lifespan of the disc. The actual OC census contain more than 3000 objects, but suffers of incom- pleteness out of the solar neighborhood and of large inhomogeneity in the parameter deter- minations present in literature. Both these aspects will be improved by the on-going space mission Gaia . In the next years Gaia will produce the most precise three-dimensional map of the Milky Way by surveying other than 1 billion of stars. For those stars Gaia will provide extremely precise measure- ment of proper motions, parallaxes and brightness. Aims. In this framework we plan to take advantage of the first Gaia data release, while preparing for the coming ones, to: i) move the first steps towards building a homogeneous data base of OCs with the high quality Gaia astrometry and photometry; ii) build, improve and test tools for the analysis of large sample of OCs; iii) use the OCs to explore the prop- erties of the disc in the solar neighborhood. Methods and Data. Using ESO archive data, we analyze the photometry and derive physical parameters, comparing data with synthetic populations and luminosity functions, of three clusters namely NGC 2225, NGC 6134 and NGC 2243. -
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). -
A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?
geosciences Review A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What? José A. Caballero Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain; [email protected] Received: 23 August 2018; Accepted: 10 September 2018; Published: 28 September 2018 Abstract: “Free-floating, non-deuterium-burning, substellar objects” are isolated bodies of a few Jupiter masses found in very young open clusters and associations, nearby young moving groups, and in the immediate vicinity of the Sun. They are neither brown dwarfs nor planets. In this paper, their nomenclature, history of discovery, sites of detection, formation mechanisms, and future directions of research are reviewed. Most free-floating, non-deuterium-burning, substellar objects share the same formation mechanism as low-mass stars and brown dwarfs, but there are still a few caveats, such as the value of the opacity mass limit, the minimum mass at which an isolated body can form via turbulent fragmentation from a cloud. The least massive free-floating substellar objects found to date have masses of about 0.004 Msol, but current and future surveys should aim at breaking this record. For that, we may need LSST, Euclid and WFIRST. Keywords: planetary systems; stars: brown dwarfs; stars: low mass; galaxy: solar neighborhood; galaxy: open clusters and associations 1. Introduction I can’t answer why (I’m not a gangstar) But I can tell you how (I’m not a flam star) We were born upside-down (I’m a star’s star) Born the wrong way ’round (I’m not a white star) I’m a blackstar, I’m not a gangstar I’m a blackstar, I’m a blackstar I’m not a pornstar, I’m not a wandering star I’m a blackstar, I’m a blackstar Blackstar, F (2016), David Bowie The tenth star of George van Biesbroeck’s catalogue of high, common, proper motion companions, vB 10, was from the end of the Second World War to the early 1980s, and had an entry on the least massive star known [1–3].