Hubble Spots a Curious Spiral 15 November 2019, by Isabelle Yan

Total Page：16

File Type：pdf, Size：1020Kb

Image: Hubble spots a curious spiral 15 November 2019, by Isabelle Yan thought to funnel and transport material through the galactic core, possibly fueling and igniting various processes such as star formation. Provided by NASA's Goddard Space Flight Center Credit: ESA/Hubble & NASA, A. Seth et al The universe is simply so vast that it can be difficult to maintain a sense of scale. Many galaxies we see through telescopes such as the NASA/ESA Hubble Space Telescope, the source of this beautiful image, look relatively similar: spiraling arms, a glowing center, and a mixture of bright specks of star formation and dark ripples of cosmic dust weaving throughout. This galaxy, a spiral galaxy named NGC 772, is no exception. It actually has much in common with our home galaxy, the Milky Way. Each boasts a few satellite galaxies, small galaxies that closely orbit and are gravitationally bound to their parent galaxies. One of NGC 772's spiral arms has been distorted and disrupted by one of these satellites (NGC 770—not visible in the image here), leaving it elongated and asymmetrical. However, the two are also different in a few key ways. For one, NGC 772 is both a peculiar and an unbarred spiral galaxy; respectively, this means that it is somewhat odd in size, shape or composition, and that it lacks a central feature known as a bar, which we see in many galaxies throughout the cosmos—including the Milky Way. These bars are built of gas and stars, and are 1 / 2 APA citation: Image: Hubble spots a curious spiral (2019, November 15) retrieved 24 September 2021 from https://phys.org/news/2019-11-image-hubble-curious-spiral.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. 2 / 2 Powered by TCPDF (www.tcpdf.org).

Copy Link

Recommended publications

CO Multi-Line Imaging of Nearby Galaxies (COMING) IV. Overview Of
Publ. Astron. Soc. Japan (2018) 00(0), 1–33 1 doi: 10.1093/pasj/xxx000 CO Multi-line Imaging of Nearby Galaxies (COMING) IV. Overview of the Project Kazuo SORAI1, 2, 3, 4, 5, Nario KUNO4, 5, Kazuyuki MURAOKA6, Yusuke MIYAMOTO7, 8, Hiroyuki KANEKO7, Hiroyuki NAKANISHI9 , Naomasa NAKAI4, 5, 10, Kazuki YANAGITANI6 , Takahiro TANAKA4, Yuya SATO4, Dragan SALAK10, Michiko UMEI2 , Kana MOROKUMA-MATSUI7, 8, 11, 12, Naoko MATSUMOTO13, 14, Saeko UENO9, Hsi-An PAN15, Yuto NOMA10, Tsutomu, T. TAKEUCHI16 , Moe YODA16, Mayu KURODA6, Atsushi YASUDA4 , Yoshiyuki YAJIMA2 , Nagisa OI17, Shugo SHIBATA2, Masumichi SETA10, Yoshimasa WATANABE4, 5, 18, Shoichiro KITA4, Ryusei KOMATSUZAKI4 , Ayumi KAJIKAWA2, 3, Yu YASHIMA2, 3, Suchetha COORAY16 , Hiroyuki BAJI6 , Yoko SEGAWA2 , Takami TASHIRO2 , Miho TAKEDA6, Nozomi KISHIDA2 , Takuya HATAKEYAMA4 , Yuto TOMIYASU4 and Chey SAITA9 1Department of Physics, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 2Department of Cosmosciences, Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 3Department of Physics, School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 4Division of Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan 5Tomonaga Center for the History of the Universe (TCHoU), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan 6Department of Physical Science, Osaka Prefecture University, Gakuen 1-1,
[Show full text]
Stellar Tidal Streams As Cosmological Diagnostics: Comparing Data and Simulations at Low Galactic Scales
RUPRECHT-KARLS-UNIVERSITÄT HEIDELBERG DOCTORAL THESIS Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Author: Referees: Gustavo MORALES Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL Astronomisches Rechen-Institut Heidelberg Graduate School of Fundamental Physics Department of Physics and Astronomy 14th May, 2018 ii DISSERTATION submitted to the Combined Faculties of the Natural Sciences and Mathematics of the Ruperto-Carola-University of Heidelberg, Germany for the degree of DOCTOR OF NATURAL SCIENCES Put forward by GUSTAVO MORALES born in Copiapo ORAL EXAMINATION ON JULY 26, 2018 iii Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Referees: Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL iv NOTE: Some parts of the written contents of this thesis have been adapted from a paper submitted as a co-authored scientiﬁc publication to the Astronomy & Astrophysics Journal: Morales et al. (2018). v NOTE: Some parts of this thesis have been adapted from a paper accepted for publi- cation in the Astronomy & Astrophysics Journal: Morales, G. et al. (2018). “Systematic search for tidal features around nearby galaxies: I. Enhanced SDSS imaging of the Local Volume". arXiv:1804.03330. DOI: 10.1051/0004-6361/201732271 vii Abstract In hierarchical models of galaxy formation, stellar tidal streams are expected around most galaxies. Although these features may provide useful diagnostics of the LCDM model, their observational properties remain poorly constrained. Statistical analysis of the counts and properties of such features is of interest for a direct comparison against results from numeri- cal simulations. In this work, we aim to study systematically the frequency of occurrence and other observational properties of tidal features around nearby galaxies.
[Show full text]
Experiencing Hubble
PRESCOTT ASTRONOMY CLUB PRESENTS EXPERIENCING HUBBLE John Carter August 7, 2019 GET OUT LOOK UP • When Galaxies Collide https://www.youtube.com/watch?v=HP3x7TgvgR8 • How Hubble Images Get Color https://www.youtube.com/watch? time_continue=3&v=WSG0MnmUsEY Experiencing Hubble Sagittarius Star Cloud 1. 12,000 stars 2. ½ percent of full Moon area. 3. Not one star in the image can be seen by the naked eye. 4. Color of star reﬂects its surface temperature. Eagle Nebula. M 16 1. Messier 16 is a conspicuous region of active star formation, appearing in the constellation Serpens Cauda. This giant cloud of interstellar gas and dust is commonly known as the Eagle Nebula, and has already created a cluster of young stars. The nebula is also referred to the Star Queen Nebula and as IC 4703; the cluster is NGC 6611. With an overall visual magnitude of 6.4, and an apparent diameter of 7', the Eagle Nebula's star cluster is best seen with low power telescopes. The brightest star in the cluster has an apparent magnitude of +8.24, easily visible with good binoculars. A 4" scope reveals about 20 stars in an uneven background of fainter stars and nebulosity; three nebulous concentrations can be glimpsed under good conditions. Under very good conditions, suggestions of dark obscuring matter can be seen to the north of the cluster. In an 8" telescope at low power, M 16 is an impressive object. The nebula extends much farther out, to a diameter of over 30'. It is ﬁlled with dark regions and globules, including a peculiar dark column and a luminous rim around the cluster.
[Show full text]
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.
[Show full text]
Zerohack Zer0pwn Youranonnews Yevgeniy Anikin Yes Men
Zerohack Zer0Pwn YourAnonNews Yevgeniy Anikin Yes Men YamaTough Xtreme x-Leader xenu xen0nymous www.oem.com.mx www.nytimes.com/pages/world/asia/index.html www.informador.com.mx www.futuregov.asia www.cronica.com.mx www.asiapacificsecuritymagazine.com Worm Wolfy Withdrawal* WillyFoReal Wikileaks IRC 88.80.16.13/9999 IRC Channel WikiLeaks WiiSpellWhy whitekidney Wells Fargo weed WallRoad w0rmware Vulnerability Vladislav Khorokhorin Visa Inc. Virus Virgin Islands "Viewpointe Archive Services, LLC" Versability Verizon Venezuela Vegas Vatican City USB US Trust US Bankcorp Uruguay Uran0n unusedcrayon United Kingdom UnicormCr3w unfittoprint unelected.org UndisclosedAnon Ukraine UGNazi ua_musti_1905 U.S. Bankcorp TYLER Turkey trosec113 Trojan Horse Trojan Trivette TriCk Tribalzer0 Transnistria transaction Traitor traffic court Tradecraft Trade Secrets "Total System Services, Inc." Topiary Top Secret Tom Stracener TibitXimer Thumb Drive Thomson Reuters TheWikiBoat thepeoplescause the_infecti0n The Unknowns The UnderTaker The Syrian electronic army The Jokerhack Thailand ThaCosmo th3j35t3r testeux1 TEST Telecomix TehWongZ Teddy Bigglesworth TeaMp0isoN TeamHav0k Team Ghost Shell Team Digi7al tdl4 taxes TARP tango down Tampa Tammy Shapiro Taiwan Tabu T0x1c t0wN T.A.R.P. Syrian Electronic Army syndiv Symantec Corporation Switzerland Swingers Club SWIFT Sweden Swan SwaggSec Swagg Security "SunGard Data Systems, Inc." Stuxnet Stringer Streamroller Stole* Sterlok SteelAnne st0rm SQLi Spyware Spying Spydevilz Spy Camera Sposed Spook Spoofing Splendide
[Show full text]
Modelling Gaseous and Stellar Kinematics in the Disc ? , Galaxies NGC 772, NGC 3898, and NGC 7782 †
Mon. Not. R. Astron. Soc. 000, 000 000 (2000) View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Modelling gaseous and stellar kinematics in the disc ? ; galaxies NGC 772, NGC 3898, and NGC 7782 † E. Pignatelli1 , E.M. Corsini2, J.C. Vega Beltrán3, C. Scarlata4, A. Pizzella2, J.G. Funes, S.J 1SISSA, via Beirut 2-4,‡ I-34013 Trieste, Italy 2Osservatorio Astrofisico di Asiago, Dipartimento di Astronomia, Università di Padova, via dell’Osservatorio 8, I-36012 Asiago, Italy 3Instituto Astrof´ısico de Canarias, Calle Via Lactea s/n, E-38200 La Laguna, Spain 4Dipartimento di Astronomia, Università di Padova, vicolo dell’Osservatorio 5, I-35122 Padova, Italy 5Vatican Observatory, University of Arizona, Tucson, AZ 85721, USA 6Institut für Astronomie, Universität Wien, Türkenschanzstraße 17, A-1180 Wien, Austria Received..................; accepted................... ABSTRACT We present V band surface photometry and major-axis kinematics of stars and ionized gas of three early-type− spiral galaxies, namely NGC 772, NGC 3898 and NGC 7782. For each galaxy we present a self-consistent Jeans model for the stellar kinematics, adopting the light distribution of bulge and disc derived by means of a two-dimensional parametric photometric decomposition. This allowed us to investigate the presence of non-circular gas motions, and derive the mass distribution of luminous and dark matter in these objects. NGC 772 and NGC 7782 have apparently normal kinematics with the ionized gas trac- ing the gravitational equilibrium circular speed. This is not true in the innermost region ( r 800) of NGC 3898 where the ionized gas is rotating more slowly than the circular velocity| | predicted by dynamical modelling.
[Show full text]
Distant Arm - NGC772
29 September 2016, Zeiss Cas 150/2250 Distant Arm - NGC772 Telescope: Zeiss Cassegrain 150/2250 Eyepieces: ATC53P - ATC Plossl, f=53mm, (42×, 530) ATC20K - ATC Kellner, f=20mm, (113×, 220) A-16 - Zeiss Abbe Ortho, f=16mm, (141×, 200) O-12.5 - CZJ Ortho, f=12.5mm, (180×, 140) Time: 2016/09/29 19:30-21:40UT Location: R´ıˇcanyˇ Weather: Clear sky with slight haze and decaying small thin clouds. Mount: Zeiss 1b Accessories: Baader/Zeiss T2 prism This was my typical backyard session. I could go out only for a short time after I put all three kids in to their beds. The night was still warm. Normally, I would try to take an advantage of it and go to some darker place. As I was alone with the kids for the whole week I was bound to stay in our backyard. During last couple of years, I have learnt to live with this handicap. There is always something interesting to look at, even with small refractors. Recently, I was explor- ing the capability of my largest telescope, 150mm Cassegrain. For this night, the main targets were two galaxies, NGC 660 and NGC 772, which I had troubles to locate two days before in 80mm refractor. I was curios how much of help the larger telescope would be. I did not jump to these two galaxies im- mediately. They were still low in the slight haze enhanced by the street lamps. I started a little bit higher in Andromeda with beau- tiful edge-on galaxy NGC 891 (V=10.0, 13:50 ×2:50, PA22◦).
[Show full text]
The Nanograv 11 Yr Data Set: Limits on Supermassive Black Hole Binaries in Galaxies Within 500 Mpc
The Astrophysical Journal, 914:121 (15pp), 2021 June 20 https://doi.org/10.3847/1538-4357/abfcd3 © 2021. The American Astronomical Society. All rights reserved. The NANOGrav 11 yr Data Set: Limits on Supermassive Black Hole Binaries in Galaxies within 500 Mpc Zaven Arzoumanian1, Paul T. Baker2 , Adam Brazier3, Paul R. Brook4,5 , Sarah Burke-Spolaor4,5 , Bence Becsy6 , Maria Charisi7,8,38 , Shami Chatterjee3 , James M. Cordes3 , Neil J. Cornish6 , Froneﬁeld Crawford9 , H. Thankful Cromartie10 , Megan E. DeCesar11 , Paul B. Demorest12 , Timothy Dolch13,14 , Rodney D. Elliott15 , Justin A. Ellis16, Elizabeth C. Ferrara17 , Emmanuel Fonseca18 , Nathan Garver-Daniels4,5 , Peter A. Gentile4,5 , Deborah C. Good19 , Jeffrey S. Hazboun20 , Kristina Islo21, Ross J. Jennings3 , Megan L. Jones21 , Andrew R. Kaiser4,5 , David L. Kaplan21 , Luke Zoltan Kelley22 , Joey Shapiro Key20 , Michael T. Lam23,24 , T. Joseph W. Lazio7,25, Jing Luo26 , Ryan S. Lynch27 , Chung-Pei Ma28 , Dustin R. Madison4,5,39 , Maura A. McLaughlin4,5 , Chiara M. F. Mingarelli29,30 , Cherry Ng31 , David J. Nice11 , Timothy T. Pennucci32,33,40 , Nihan S. Pol4,5,8 , Scott M. Ransom32 , Paul S. Ray34 , Brent J. Shapiro-Albert4,5 , Xavier Siemens21,35 , Joseph Simon7,25 , Renée Spiewak36 , Ingrid H. Stairs19 , Daniel R. Stinebring37 , Kevin Stovall12 , Joseph K. Swiggum11,41 , Stephen R. Taylor8 , Michele Vallisneri7,25 , Sarah J. Vigeland21 , and Caitlin A. Witt4,5 The NANOGrav Collaboration 1 X-Ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771, USA 2 Department of Physics and Astronomy, Widener University, One University Place, Chester, PA 19013, USA 3 Cornell Center for Astrophysics and Planetary Science and Department of Astronomy, Cornell University, Ithaca, NY 14853, USA 4 Department of Physics and Astronomy, West Virginia University, P.O.
[Show full text]
AHSP Telescope Observing Award
AHSP Telescope Observing Award Compiled by Dan L. Ward • To qualify for the TOA pin, you must see 15 of the following 20 telescope targets. Check off each as you spot them. Seen # Object Const. Type* RA Dec Mag Size Nickname 1. M13 Her GC 16 41.7 +36 28 5.9 16' Great Hercules Globular 2. M57 Lyr PN 18 53.6 +33 02 9.7 86"x62" Ring Nebula 3. NGC 6819 Cyg OC 19 41.3 +40 11 7.3 5’ Fox Head Cluster 4. M27 Vul PN 19 59.6 +22 43 8.1 8’x6’ Dumbbell Nebula 5. NGC 7000 Cyg BN 20 58.8 +44 20 - 120'x100' North America Nebula 6. NGC 7009 Aqr PN 21 04.2 -11 22 8.3 28”x23” Saturn Nebula 7. M15 Peg GC 21 30.0 +12 10 7.5 12’ Great Pegasus Cluster 8. M2 Aqr GC 21 33.5 -00 49 6.3 16’ NGC 7089 9. M39 Cyg OC 21 32.2 +48 26 4.6 32' NGC 7092 10. M30 Cap GC 21 40.4 -23 11 8.4 11’x11’ NGC 7099 11. NGC 7331 Peg Gx 22 37.1 +34 25 10.4 11’x4’ Caldwell 30 12. M31 And Gx 00 42.8 +41 16 4.5 178’ Andromeda Galaxy 13. NGC 253 Scl Gx 00 47.5 -25 18 7.1 25’x7’ Sculptor Galaxy 14. NGC 457 Cas OC 01 19.1 +58 20 6.4 13’ Owl Cluster/ET Cluster 15. M74 Psc Gx 01 36.7 +15 47 10.5 10’x9.5’ The Phantom 16.
[Show full text]
Arxiv:2101.02716V1 [Astro-Ph.GA] 7 Jan 2021 Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin-Milwaukee, P.O
Draft version January 11, 2021 Typeset using LATEX twocolumn style in AASTeX63 The NANOGrav 11 yr Data Set: Limits on Supermassive Black Hole Binaries in Galaxies within 500 Mpc Zaven Arzoumanian,1 Paul T. Baker ,2 Adam Brazier,3 Paul R. Brook ,4, 5 Sarah Burke-Spolaor ,4, 5 Bence Becsy,6 Maria Charisix ,7, 8, ∗ Shami Chatterjee ,3 James M. Cordes ,3 Neil J. Cornish ,6 Fronefield Crawford ,9 H. Thankful Cromartie ,10 Megan E. DeCesar ,11 Paul B. Demorest ,12 Timothy Dolch ,13 Rodney D. Elliott,14 Justin A. Ellis,15 Elizabeth C. Ferrara,16 Emmanuel Fonseca ,17 Nathan Garver-Daniels ,4, 5 Peter A. Gentile ,4, 5 Deborah C. Good ,18 Jeffrey S. Hazboun ,19 Kristina Islo,20 Ross J. Jennings ,3 Megan L. Jones ,20 Andrew R. Kaiser ,4, 5 David L. Kaplan ,20 Luke Zoltan Kelley ,21 Joey Shapiro Key ,19 Michael T. Lam ,22, 23 T. Joseph W. Lazio,24, 7 Jing Luo,25 Ryan S. Lynch ,26 Chung-Pei Ma,27 Dustin R. Madison ,4, 5, ∗ Maura A. McLaughlin ,4, 5 Chiara M. F. Mingarelli ,28, 29 Cherry Ng ,30 David J. Nice ,11 Timothy T. Pennucci ,31, 32, ∗ Nihan S. Pol ,4, 8, 5 Scott M. Ransom ,31 Paul S. Ray ,33 Brent J. Shapiro-Albert ,4, 5 Xavier Siemens ,34, 20 Joseph Simon ,24, 7 Renee´ Spiewak ,35 Ingrid H. Stairs ,18 Daniel R. Stinebring ,36 Kevin Stovall ,12 Joseph K. Swiggum ,11, ∗ Stephen R. Taylor ,8 Michele Vallisneri ,24, 7 Sarah J. Vigeland ,20 Caitlin A. Witt ,4, 5 The NANOGrav Collaboration 1X-Ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771, USA 2Department of Physics and Astronomy, Widener University, One University Place, Chester, PA 19013, USA 3Cornell Center for Astrophysics and Planetary Science and Department of Astronomy, Cornell University, Ithaca, NY 14853, USA 4Department of Physics and Astronomy, West Virginia University, P.O.
[Show full text]
Spatial Distributions of Core-Collapse Supernovae in Infrared-Bright Galaxies 3
Mon. Not. R. Astron. Soc. 000, 1–18 (2013) Printed 8 May 2019 (MN LATEX style file v2.2) Spatial distributions of core-collapse supernovae in infrared-bright galaxies T. Kangas1,2⋆, S. Mattila3, E. Kankare3, J. K. Kotilainen3, P. Väisänen4, R. Greimel5 and A. Takalo1 1Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, FI-21500 Piikkiö, Finland 2Nordic Optical Telescope, Apartado 474, E-38700 Santa Cruz de La Palma, Spain 3Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, FI-21500 Piikkiö, Finland 4South African Astronomical Observatory, PO Box 9, 7935 Observatory, Cape Town, South Africa 5Institut für Physik, Universität Graz, Universitätsplatz 5/II, A-8010 Graz, Austria 2013 ABSTRACT We have measured the correlation between the locations of core-collapse supernovae (CCSNe) and host galaxy light in the Hα line, near ultraviolet (NUV), R-band and Ks-band to constrain the progenitors of CCSNe using pixel statistics. Our sample consists of 86 CCSNe in 57 infrared (IR) -bright galaxies, of which many are star- bursts and ten are luminous infrared galaxies (LIRGs). We also analyse the radial distribution of CCSNe in these galaxies, and determine power-law and exponential fits to CCSN surface density profiles. To probe differences between the SN population of these galaxies and normal spiral galaxies, our results were compared to previous similar studies with samples dominated by normal spiral galaxies where possible. We +0.03 obtained a normalised scale length of 0.23−0.02 R25 for the surface density of CCSNe in IR-bright galaxies; less than that derived for CCSNe in a galaxy sample dominated by normal spiral galaxies (0.29 ± 0.01).
[Show full text]
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.
[Show full text]