DOCSLIB.ORG

Name Type M Size Con G1

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Name Type m Size Con G1 - Mayall II GCL 13.7 2000 And + NGC 910 - Abell 347 Gal 12.2 2:00 × 2:00 And + NGC 6749 GCL 12.4 6:30 Aql + NGC 6751 PN 11.9 2100 Aql + Palomar 11 GCL 9.8 100 Aql + NGC 1985 BNL 12.7b 1:20 × 1:20 Aur { NGC 1569 Gal 11.3 2:90 × 1:50 Cam + IC 391 Gal 12.7 1:10 × 1:00 Cam { NGC 2336 Gal 10.7 7:10 × 3:90 Cam ? NGC 2366 Gal 11.0 8:10 × 3:30 Cam + NGC 2715 Gal 11.3 4:90 × 1:70 Cam { Abell 2 PN 14.5 3300 Cas { NGC 609 OCL 11.0 30 Cas + Abell 82 PN 12.7 9400 Cas { Abell 84 PN 13 14700 Cas { NGC 2276 Gal 11.8 2:60 × 2:50 Cep + NGC 7076 - Abell 75 PN 14.5 6700 Cep + IC 1454 - Abell 81 PN 14.4 3400 Cep + UGC 11465 Gal 12.8 1:30 × 1:30 Cyg + Abell 72 PN 12.7 13400 Del { Abell 39 PN 12.9 17000 Her { Minkowski 64 PN 13.3 1800 Lyr + Pegasus Dwarf Gal 12 4:60 × 3:00 Peg { Jones 1 PN 12.1 33000 Peg + Abell 4 PN 14.8 2200 Per { Name Type m Size Con IC 348 OCL 7.3 70 Per + NGC 660 Gal 11.4 8:30 × 3:20 Psc + NGC 3065 Gal 11.9 2:00 × 1:00 UMa { G1 - Mayall II And Globular Cluster α = 00h 32m 46:54s, δ = 39◦ 340 40:400 Magnitude: 13.7 Size: 2000 In galaxy M31. Probably nucleus of dwarf galaxy. Notes: ED100+, ED130+ Digital Sky Survey FOV: 2◦ Box FOV: 180 Mag cut: 11.7 M31 G1 stars from catalog Tycho2 G1 - Mayall II page 3 NGC 910 - Abell 347 And Galaxy α = 02h 25m 26:9s, δ = 41◦ 490 2700 Magnitude: 12.2 Size: 2:00 × 2:00 SB: 13.3 PA: 90◦ Type: E Notes: AS80+, C63-, Cas150+ Digital Sky Survey FOV: 1:5◦ Box FOV: 150 Mag cut: 11.7 891 914 906 898 911 910 stars from catalog Tycho2 NGC 910 - Abell 347 page 4 NGC 6749 Aql Globular Cluster α = 19h 05m 15:6s, δ = 01◦ 540 0200 Magnitude: 12.4 Size: 6:30 Notes: AS110-, Cas150+ Digital Sky Survey FOV: 1:5◦ Box FOV: 200 Mag cut: 11.5 6749 TT stars from catalog Tycho2 NGC 6749 page 5 NGC 6751 Aql Planetary Nebula α = 19h 05m 55:5s, δ = −05◦ 590 3200 Magnitude: 11.9 Size: 2100 Type: 3 Notes: AS110-, Cas150+ Digital Sky Survey FOV: 2:5◦ Box FOV: 150 Mag cut: 11.2 12 6751 stars from catalog Tycho2 NGC 6751 page 6 Palomar 11 Aql Globular Cluster α = 19h 45m 14:4s, δ = −08◦ 000 2600 Magnitude: 9.8 Size: 100 Notes: AS110-, Cas150+, N250- Digital Sky Survey FOV: 2◦ Box FOV: 200 Mag cut: 11.5 Pal11 stars from catalog Tycho2 Palomar 11 page 7 NGC 1985 Aur Bright Nebula α = 05h 37m 47:8s, δ = +31◦ 590 2000 Magnitude: 12.7b Size: 1:20 × 1:20 Type: Reflection Notes: ATC82- Digital Sky Survey FOV: 2:4◦ Box FOV: 150 Mag cut: 11.5 χ 1985 Berk71 stars from catalog Tycho2 NGC 1985 page 8 NGC 1569 Cam Galaxy α = 04h 30m 49:2s, δ = +64◦ 500 5100 Magnitude: 11.3 Size: 2:90 × 1:50 SB: 13.2 PA: 120◦ Type: Irr III Notes: AS80+, C63- Digital Sky Survey FOV: 2:5◦ Box FOV: 150 Mag cut: 11.5 1569 stars from catalog Tycho2 NGC 1569 page 9 IC 391 Cam Galaxy α = 04h 57m 21:1s, δ = +78◦ 110 2900 Magnitude: 12.7 Size: 1:10 × 1:00 Type: SAB(s)cd pec? Notes: AS110- Digital Sky Survey FOV: 1:6◦ Box FOV: 150 Mag cut: 12 I391 stars from catalog Tycho2 IC 391 page 10 NGC 2336 Cam Galaxy α = 07h 27m 04:1s, δ = +80◦ 100 4100 Magnitude: 10.7 Size: 7:10 × 3:90 SB: 14.2 PA: 175◦ Type: SBc Notes: ED130? Digital Sky Survey FOV: 2◦ Box FOV: 200 Mag cut: 11.5 IC467 Galaxy Mag.: 12.0 Size: 3:50 × 3:50 2336 I467 stars from catalog Tycho2 NGC 2336 page 11 NGC 2366 Cam Galaxy α = 07h 28m 54:7s, δ = +69◦ 120 5700 Magnitude: 11.0 Size: 8:10 × 3:30 SB: 14.4 PA: 25◦ Type: IB(s)m IV-V Member of M81 group. Strong starforming regions, the brightest HII region was seen by WH and marked as NGC 2366. Detached rea- gion west is separate galaxy NGC 2363. Notes: AS110+,ED100- Digital Sky Survey FOV: 2◦ Box FOV: 200 Mag cut: 11.5 2366 stars from catalog Tycho2 NGC 2366 page 12 NGC 2715 Cam Galaxy α = 09h 08m 06:5s, δ = +78◦ 050 0600 Magnitude: 11.3 Size: 4:90 × 1:70 SB: 13.4 PA: 22◦ Type: Irr III Notes: AS80-, ED130- Digital Sky Survey FOV: 2◦ Box FOV: 200 Mag cut: 12.0 NGC2655 Galaxy Mag.: 10.1 Size: 4:90 × 4:10 2655 SB: 13.2 2715 FL PA: 90◦ stars from catalog Tycho2 NGC 2715 page 13 Abell 2 Cas Planetary Nebula α = 00h 45m 36s, δ = +57◦ 570 2400 Magnitude: 14.5 Size: 3300 Digital Sky Survey FOV: 1◦ Box FOV: 120 Mag cut: 11.7 A2 η stars from catalog Tycho2 Abell 2 page 14 NGC 609 Cas Open Cluster α = 01h 36m 23:7s, δ = 64◦ 320 1200 Magnitude: 11.0 Size: 30 Type: II 3 r Notes: C63?, AS80-, Cas150+ Digital Sky Survey FOV: 2◦ Box FOV: 150 Mag cut: 10.5 NGC 637 Open Cluster Mag.: 8.2 Size: 3:50 609 637 stars from catalog Tycho2 NGC 609 page 15 Abell 82 Cas Planetary Nebula α = 23h 45m 47:8s, δ = +57◦ 030 5900 Magnitude: 12.7 Size: 9400 Digital Sky Survey FOV: 2:5◦ Box FOV: 120 Mag cut: 11.5 Berk 102 Open Cluster ρ Size: 50 A82 Be102 stars from catalog Tycho2 Abell 82 page 16 Abell 84 Cas Planetary Nebula α = 23h 47m 44:3s, δ = +51◦ 230 5600 Magnitude: 13 Size: 14700 Digital Sky Survey FOV: 3◦ Box FOV: 240 Mag cut: 11.2 A84 18 stars from catalog Tycho2 Abell 84 page 17 NGC 2276 Cep Galaxy α = 07h 27m 14:4s, δ = +85◦ 450 1600 Magnitude: 11.8 Size: 2:60 × 2:50 SB: 13.8 PA: 20◦ Type: Sc I Pair with NGC 2300 Notes: AS80+, ED130- Digital Sky Survey FOV: 2◦ Box FOV: 200 Mag cut: 11.5 NGC2300 Galaxy Mag.: 11.1 Size: 2:80 × 2:00 SB: 12.9 2276 PA: 90◦ 2300 I469 stars from catalog Tycho2 NGC 2276 page 18 NGC 7076 - Abell 75 Cep Planetary Nebula α = 21h 26m 23:6s, δ = +62◦ 530 3300 Magnitude: 14.5 Size: 6700 Notes: AS110-, Cas150+ Digital Sky Survey FOV: 2◦ Box FOV: 180 Mag cut: 12.2 7076 α stars from catalog Tycho2 NGC 7076 - Abell 75 page 19 IC 1454 - Abell 81 Cep Planetary Nebula α = 22h 42m 25s, δ = +80◦ 260 3200 Magnitude: 14.4 Size: 3400 Notes: ED130?, Cas150+ Digital Sky Survey FOV: 3:5◦ Box FOV: 150 Mag cut: 11.0 A81 ρ 28 stars from catalog Tycho2 IC 1454 - Abell 81 page 20 UGC 11465 Cyg Galaxy α = 19h 41m 42:3s, δ = 50◦ 370 5600 Magnitude: 12.8 Size: 1:30 × 1:30 SB: 13.0 PA: 90◦ Type: S(B)0 Notes: AS110-, Cas150+ Digital Sky Survey FOV: 1◦ Box FOV: 150 Mag cut: 11.5 U11465 3C402 16 stars from catalog Tycho2 UGC 11465 page 21 Abell 72 Del Planetary Nebula α = 20h 50m 02s, δ = +13◦ 330 2800 Magnitude: 12.7 Size: 13400 Notes: Cas150- Digital Sky Survey FOV: 3◦ Box FOV: 120 Mag cut: 11.2 17 A72 15 16 stars from catalog Tycho2 Abell 72 page 22 Abell 39 Her Planetary Nebula α = 16h 27m 33:6s, δ = +27◦ 540 3400 Magnitude: 12.9 Size: 17000 Digital Sky Survey FOV: 5◦ Box FOV: 300 Mag cut: 11.2 υ A39 19 stars from catalog Tycho2 Abell 39 page 23 Minkowski 64 Lyr Planetary Nebula α = 18h 50m 02s, δ = +35◦ 140 3500 Magnitude: 13.3 Size: 1800 Notes: ATC82-, Cas150+ Digital Sky Survey FOV: 4◦ 0 δ Box FOV: 15 Steph1 1 δ Mag cut: 10.8 2 Mi64 β stars from catalog Tycho2 Minkowski 64 page 24 Pegasus Dwarf Peg Galaxy α = 23h 28m 36s, δ = 14◦ 500 3800 Magnitude: 12 Size: 4:60 × 3:00 SB: 13.0 PA: 120◦ Type: Ir+O Baral Digital Sky Survey FOV: 5◦ Box FOV: 600 Mag cut: 11 NGC7711 7703 Galaxy 7691 Mag.: 12.1 Size: 2:60 × 1:30 7711 7653 ◦ PA: 95 U12613 7649 NGC7653 Galaxy 7659 Mag.: 12.7 Size: 1:60 × 1:50 PA: 90◦ 70 stars from catalog Tycho2 Pegasus Dwarf page 25 Jones 1 Peg Planetary Nebula α = 23h 35m 53:3s, δ = +30◦ 280 0600 Magnitude: 12.1 Size: 33000 Type: 3b Notes: ATC82-, Ba95+, Cas150+ Digital Sky Survey FOV: 2◦ Box FOV: 200 72 Mag cut: 11.7 U12713 Jones1 U12667 stars from catalog Tycho2 Jones 1 page 26 Abell 4 Per Planetary Nebula α = 02h 45m 23:7s, δ = +42◦ 330 0500 Magnitude: 14.8 Size: 2200 Digital Sky Survey FOV: 2◦ Box FOV: 120 Mag cut: 11.7 M34 A4 stars from catalog Tycho2 Abell 4 page 27 IC 348 Per Open Cluster α = 03h 44m 34s, δ = 32◦ 090 4800 Magnitude: 7.3 Size: 70 Type: IV 3 p n Br? Σ439 (9.3+10.3, 24"), with neb, 2 My old.
Recommended publications
  • The HERACLES View of the H -To-HI Ratio in Galaxies

    The HERACLES View of the H -To-HI Ratio in Galaxies

    The HERACLES View of the H2-to-HI Ratio in Galaxies Adam Leroy (NRAO, Hubble Fellow) Fabian Walter, Frank Bigiel, the HERACLES and THINGS teams The Saturday Morning Summary • Star formation rate vs. gas relation on ~kpc scales breaks apart into: A relatively universal CO-SFR relation in nearby disks Systematic environmental scalings in the CO-to-HI ratio • The CO-to-HI ratio is a strong function of radius, total gas, and stellar surface density correlated with ISM properties: dust-to-gas ratio, pressure harder to link to dynamics: gravitational instability, arms • Interpretation: the CO-to-HI ratio traces the efficiency of GMC formation Density and dust can explain much of the observed behavior heracles Fabian Walter Erik Rosolowsky MPIA UBC Frank Bigiel Eva Schinnerer UC Berkeley THINGS plus… MPIA Elias Brinks Antonio Usero Gaelle Dumas U Hertfordshire OAN, Madrid MPIA Erwin de Blok Andreas Schruba Helmut Wiesemeyer U Cape Town IRAM … MPIA Rob Kennicutt Axel Weiss Karl Schuster Cambridge MPIfR IRAM Barry Madore Carsten Kramer Karin Sandstrom Carnegie IRAM MPIA Michele Thornley Daniela Calzetti Kelly Foyle Bucknell UMass MPIA Collaborators The HERA CO-Line Extragalactic Survey First maps Leroy et al. (2009) • IRAM 30m Large Program to map CO J = 2→1 line • Instrument: HERA receiver array operating at 230 GHz • 47 galaxies: dwarfs to starbursts and massive spirals -2 • Very wide-field (~ r25) and sensitive (σ ~ 1-2 Msun pc ) NGS The HI Nearby Galaxy Survey HI Walter et al. (2008), AJ Special Issue (2008) • VLA HI maps of 34 galaxies:
  • Big Halpha Kinematical Sample of Barred Spiral Galaxies - I

    Big Halpha Kinematical Sample of Barred Spiral Galaxies - I

    BhaBAR: Big Halpha kinematical sample of BARred spiral galaxies - I. Fabry-Perot Observations of 21 galaxies O. Hernandez, C. Carignan, P. Amram, L. Chemin, O. Daigle To cite this version: O. Hernandez, C. Carignan, P. Amram, L. Chemin, O. Daigle. BhaBAR: Big Halpha kinematical sample of BARred spiral galaxies - I. Fabry-Perot Observations of 21 galaxies. Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P - Oxford Open Option A, 2005, 360 Issue 4, pp.1201. 10.1111/j.1365-2966.2005.09125.x. hal-00014446 HAL Id: hal-00014446 https://hal.archives-ouvertes.fr/hal-00014446 Submitted on 26 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Mon. Not. R. Astron. Soc. 360, 1201–1230 (2005) doi:10.1111/j.1365-2966.2005.09125.x BHαBAR: big Hα kinematical sample of barred spiral galaxies – I. Fabry–Perot observations of 21 galaxies O. Hernandez,1,2 † C. Carignan,1 P. Amram,2 L. Chemin1 and O. Daigle1 1Observatoire du mont Megantic,´ LAE, Universitede´ Montreal,´ CP 6128 succ. centre ville, Montreal,´ Quebec,´ Canada H3C 3J7 2Observatoire Astronomique de Marseille Provence et LAM, 2 pl.
  • Magnificent Spiral Galaxy Is Being Stretched by Passing Neighbor 27 May 2021, by Ray Villard

    Magnificent Spiral Galaxy Is Being Stretched by Passing Neighbor 27 May 2021, by Ray Villard

    Magnificent spiral galaxy is being stretched by passing neighbor 27 May 2021, by Ray Villard animals—the gingham dog and calico cat—who got into a spat and ate each other. It's not so dramatic in this case. The galaxies are only getting a little chewed up because of their close proximity. The magnificent spiral galaxy NGC 2276 looks a bit lopsided in this Hubble Space Telescope snapshot. A bright hub of older yellowish stars normally lies directly in the center of most spiral galaxies. But the bulge in NGC 2276 looks offset to the upper left. What's going on? In reality, a neighboring galaxy to the right of NGC 2276 (NGC 2300, not seen here) is gravitationally tugging on its disk of blue stars, pulling the stars on one side of the galaxy outward to distort the galaxy's normal fried-egg appearance. This sort of "tug of war" between galaxies that pass close enough to feel each other's gravitational pull is not uncommon in the universe. But, like Credit: NASA, ESA, STScI, Paul Sell (University of snowflakes, no two close encounters look exactly Florida) alike. In addition, newborn and short-lived massive stars form a bright, blue arm along the upper left edge of The myriad spiral galaxies in our universe almost NGC 2276. They trace out a lane of intense star all look like fried eggs. A central bulge of aging formation. This may have been triggered by a prior stars is like the egg yolk, surrounded by a disk of collision with a dwarf galaxy.
  • Luminous Blue Variables

    Luminous Blue Variables

    Review Luminous Blue Variables Kerstin Weis 1* and Dominik J. Bomans 1,2,3 1 Astronomical Institute, Faculty for Physics and Astronomy, Ruhr University Bochum, 44801 Bochum, Germany 2 Department Plasmas with Complex Interactions, Ruhr University Bochum, 44801 Bochum, Germany 3 Ruhr Astroparticle and Plasma Physics (RAPP) Center, 44801 Bochum, Germany Received: 29 October 2019; Accepted: 18 February 2020; Published: 29 February 2020 Abstract: Luminous Blue Variables are massive evolved stars, here we introduce this outstanding class of objects. Described are the specific characteristics, the evolutionary state and what they are connected to other phases and types of massive stars. Our current knowledge of LBVs is limited by the fact that in comparison to other stellar classes and phases only a few “true” LBVs are known. This results from the lack of a unique, fast and always reliable identification scheme for LBVs. It literally takes time to get a true classification of a LBV. In addition the short duration of the LBV phase makes it even harder to catch and identify a star as LBV. We summarize here what is known so far, give an overview of the LBV population and the list of LBV host galaxies. LBV are clearly an important and still not fully understood phase in the live of (very) massive stars, especially due to the large and time variable mass loss during the LBV phase. We like to emphasize again the problem how to clearly identify LBV and that there are more than just one type of LBVs: The giant eruption LBVs or h Car analogs and the S Dor cycle LBVs.
  • 1. Introduction

    1. Introduction

    THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 122:109È150, 1999 May ( 1999. The American Astronomical Society. All rights reserved. Printed in U.S.A. GALAXY STRUCTURAL PARAMETERS: STAR FORMATION RATE AND EVOLUTION WITH REDSHIFT M. TAKAMIYA1,2 Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637; and Gemini 8 m Telescopes Project, 670 North Aohoku Place, Hilo, HI 96720 Received 1998 August 4; accepted 1998 December 21 ABSTRACT The evolution of the structure of galaxies as a function of redshift is investigated using two param- eters: the metric radius of the galaxy(Rg) and the power at high spatial frequencies in the disk of the galaxy (s). A direct comparison is made between nearby (z D 0) and distant(0.2 [ z [ 1) galaxies by following a Ðxed range in rest frame wavelengths. The data of the nearby galaxies comprise 136 broad- band images at D4500A observed with the 0.9 m telescope at Kitt Peak National Observatory (23 galaxies) and selected from the catalog of digital images of Frei et al. (113 galaxies). The high-redshift sample comprises 94 galaxies selected from the Hubble Deep Field (HDF) observations with the Hubble Space Telescope using the Wide Field Planetary Camera 2 in four broad bands that range between D3000 and D9000A (Williams et al.). The radius is measured from the intensity proÐle of the galaxy using the formulation of Petrosian, and it is argued to be a metric radius that should not depend very strongly on the angular resolution and limiting surface brightness level of the imaging data. It is found that the metric radii of nearby and distant galaxies are comparable to each other.
  • Photo-Ionization Models of NGC 2363 and Their Implications

    Photo-Ionization Models of NGC 2363 and Their Implications

    Wolf-Rayet Phenomena in Massive Stars and Starburst Galaxies Proceedings IAU Symposium No. 193, @1999 IAU K.A. van der Hucht, G. Koenigsberger f3 P.R.J. Eenens, eds. Photo-ionization models of NGC 2363 and their implications Valentina Luridiana and Manuel Peimbert Instituto de Astronomic, UNAM, Mexico Claus Leitherer Space Telescope Science Institute, Baltimore, MD, USA. Abstract. We compute photo-ionization models for the giant extragalactic H II region NGC 2363, and compare them with optical observational data. We focus on the following observational constraints: F(Hj3), Ni; EW(Hj3), and the ratios of I(A 5007), I(A 4363), I(A 3727), I(A 6300), I(A 6720) and I(A 4686) rel- ative to I(Hj3). We discuss the variations of the emission spectra obtained with different input parameters. We show that low metallicity models (Z == 0.10 Zev) cannot reproduce the observed features of the spectrum, and that the disagree- ment can be satisfactorily overcome by allowing for spatial temperature fluctu- ations in the nebula. Accordingly, we show that the metallicity of NGC 2363 has most probably been underestimated, and that a value of Z ~ 0.25 Zev is in better agreement with the observational data than the usually adopted value Z ~ 0.10 Zev. We also derive values for the slope and the high mass end of the IMF, as well as the age of the stellar cluster. 1. Introduction NGC 2363 is a very luminous giant H II region, located in the south-west end of the irregular galaxy NGC 2366. It is one of the brightest extragalactic H II re- 6 gions known, with an estimated mass of about 2.2 x 10 M0 (Carigi & Peimbert 1999).
  • The Most Massive Star Cluster in the Local Group

    The Most Massive Star Cluster in the Local Group

    This is a repository copy of A 'super' star cluster grown old: the most massive star cluster in the Local Group. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/144713/ Version: Published Version Article: Ma, J., De Grijs, R., Yang, Y. et al. (5 more authors) (2006) A 'super' star cluster grown old: the most massive star cluster in the Local Group. Monthly Notices of the Royal Astronomical Society , 368 (3). pp. 1443-1450. ISSN 0035-8711 https://doi.org/10.1111/j.1365-2966.2006.10231.x This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2006 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Mon. Not. R. Astron. Soc. 368, 1443–1450 (2006) doi:10.1111/j.1365-2966.2006.10231.x A ‘super’ star cluster grown old: the most massive star cluster in the Local Group J.
  • Planetary Nebulae

    Planetary Nebulae

    Planetary Nebulae A planetary nebula is a kind of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from old red giant stars late in their lives. The term "planetary nebula" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years. The mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energizes the shell of nebulous gas around the central star, appearing as a bright colored planetary nebula at several discrete visible wavelengths. Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances. In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies.
  • Guide Du Ciel Profond

    Guide Du Ciel Profond

    Guide du ciel profond Olivier PETIT 8 mai 2004 2 Introduction hjjdfhgf ghjfghfd fg hdfjgdf gfdhfdk dfkgfd fghfkg fdkg fhdkg fkg kfghfhk Table des mati`eres I Objets par constellation 21 1 Androm`ede (And) Andromeda 23 1.1 Messier 31 (La grande Galaxie d'Androm`ede) . 25 1.2 Messier 32 . 27 1.3 Messier 110 . 29 1.4 NGC 404 . 31 1.5 NGC 752 . 33 1.6 NGC 891 . 35 1.7 NGC 7640 . 37 1.8 NGC 7662 (La boule de neige bleue) . 39 2 La Machine pneumatique (Ant) Antlia 41 2.1 NGC 2997 . 43 3 le Verseau (Aqr) Aquarius 45 3.1 Messier 2 . 47 3.2 Messier 72 . 49 3.3 Messier 73 . 51 3.4 NGC 7009 (La n¶ebuleuse Saturne) . 53 3.5 NGC 7293 (La n¶ebuleuse de l'h¶elice) . 56 3.6 NGC 7492 . 58 3.7 NGC 7606 . 60 3.8 Cederblad 211 (N¶ebuleuse de R Aquarii) . 62 4 l'Aigle (Aql) Aquila 63 4.1 NGC 6709 . 65 4.2 NGC 6741 . 67 4.3 NGC 6751 (La n¶ebuleuse de l’œil flou) . 69 4.4 NGC 6760 . 71 4.5 NGC 6781 (Le nid de l'Aigle ) . 73 TABLE DES MATIERES` 5 4.6 NGC 6790 . 75 4.7 NGC 6804 . 77 4.8 Barnard 142-143 (La tani`ere noire) . 79 5 le B¶elier (Ari) Aries 81 5.1 NGC 772 . 83 6 le Cocher (Aur) Auriga 85 6.1 Messier 36 . 87 6.2 Messier 37 . 89 6.3 Messier 38 .
  • Astronomy Magazine Special Issue

    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.
  • Arxiv:1704.01678V2 [Astro-Ph.GA] 28 Jul 2017 Been Notoriously Difficult, Resulting Mostly in Upper Lim- Highest Escape Fractions Measured to Date Among Low- Its (E.G

    Arxiv:1704.01678V2 [Astro-Ph.GA] 28 Jul 2017 Been Notoriously Difficult, Resulting Mostly in Upper Lim- Highest Escape Fractions Measured to Date Among Low- Its (E.G

    Submitted: 3 March 2017 Preprint typeset using LATEX style AASTeX6 v. 1.0 MRK 71 / NGC 2366: THE NEAREST GREEN PEA ANALOG Genoveva Micheva1, M. S. Oey1, Anne E. Jaskot2, and Bethan L. James3 (Accepted 24 July 2017) 1University of Michigan, 311 West Hall, 1085 S. University Ave, Ann Arbor, MI 48109-1107, USA 2Department of Astronomy, Smith College, Northampton, MA 01063, USA 3STScI, 3700 San Martin Drive, Baltimore, MD 21218, USA ABSTRACT We present the remarkable discovery that the dwarf irregular galaxy NGC 2366 is an excellent analog of the Green Pea (GP) galaxies, which are characterized by extremely high ionization parameters. The similarities are driven predominantly by the giant H II region Markarian 71 (Mrk 71). We compare the system with GPs in terms of morphology, excitation properties, specific star-formation rate, kinematics, absorption of low-ionization species, reddening, and chemical abundance, and find consistencies throughout. Since extreme GPs are associated with both candidate and confirmed Lyman continuum (LyC) emitters, Mrk 71/NGC 2366 is thus also a good candidate for LyC escape. The spatially resolved data for this object show a superbubble blowout generated by mechanical feedback from one of its two super star clusters (SSCs), Knot B, while the extreme ionization properties are driven by the . 1 Myr-old, enshrouded SSC Knot A, which has ∼ 10 times higher ionizing luminosity. Very massive stars (> 100 M ) may be present in this remarkable object. Ionization-parameter mapping indicates the blowout region is optically thin in the LyC, and the general properties also suggest LyC escape in the line of sight.
  • The Hot, Warm and Cold Gas in Arp 227 - an Evolving Poor Group R

    The Hot, Warm and Cold Gas in Arp 227 - an Evolving Poor Group R

    The hot, warm and cold gas in Arp 227 - an evolving poor group R. Rampazzo, P. Alexander, C. Carignan, M.S. Clemens, H. Cullen, O. Garrido, M. Marcelin, K. Sheth, G. Trinchieri To cite this version: R. Rampazzo, P. Alexander, C. Carignan, M.S. Clemens, H. Cullen, et al.. The hot, warm and cold gas in Arp 227 - an evolving poor group. Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P - Oxford Open Option A, 2006, 368, pp.851. 10.1111/j.1365- 2966.2006.10179.x. hal-00083833 HAL Id: hal-00083833 https://hal.archives-ouvertes.fr/hal-00083833 Submitted on 13 Dec 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Mon. Not. R. Astron. Soc. 368, 851–863 (2006) doi:10.1111/j.1365-2966.2006.10179.x The hot, warm and cold gas in Arp 227 – an evolving poor group R. Rampazzo,1 P. Alexander,2 C. Carignan,3 M. S. Clemens,1 H. Cullen,2 O. Garrido,4 M. Marcelin,5 K. Sheth6 and G. Trinchieri7 1Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy 2Astrophysics Group, Cavendish Laboratories, Cambridge CB3 OH3 3Departement´ de physique, Universite´ de Montreal,´ C.