THE OBSERVER’S HANDBOOK FOR 1955 PUBLISHED BY The Royal Astronomical Society of Canada C. A. C H A N T, E d ito r RUTH J. NORTHCOTT, A s s is t a n t E d ito r DAVID DUNLAP OBSERVATORY FORTY-SEVENTH YEAR OF PUBLICATION P r i c e 50 C e n t s TORONTO 13 Ross S t r e e t Printed for th e Society By the University of Toronto Press THE ROYAL ASTRONOMICAL SOCIETY OF CANADA The Society was incorporated in 1890 as The Astronomical and Physical Society of Toronto, assuming its present name in 1903. For many years the Toronto organization existed alone, but now the Society is national in extent, having active Centres in Montreal and Quebec, P.Q.; Ottawa, Toronto, Hamilton, London, and Windsor, Ontario; Winnipeg, Man.; Saskatoon, Sask.; Edmonton, Alta.; Vancouver and Victoria, B.C. As well as nearly 1000 members of these Canadian Centres, there are nearly 400 members not attached to any Centre, mostly resident in other nations, while some 200 additional institutions or persons are on the regular mailing list of our publications. The Society publishes a bi-monthly J o u r n a l and a yearly O b s e r v e r ’s H a n d b o o k . Single copies of the J o u r n a l are 50 cents, and of the H a n d b o o k , 50 cents. Membership is open to anyone interested in astronomy. Annual dues, $3.00; life membership, $40.00. Publications are sent free to all members or may be subscribed for separately. Applications for membership or publications may be made to the National Secretary, 13 Ross St., Toronto 2B. CALENDAR 1955 Jan. Feb. Mar. April S MTW TFS s MTW TFS SM T WTFSSM T W TFS 1 1 2 3 4 5 1 2 3 4 5 1 2 2 3 .. 5 6 7 8 6 7 8 9 10 11 12 6 7 8 9 10 11 12 3 .4 5 6 7 8 9 9 10 11 12 13 14 15 13 14 15 16 17 18 19 13 14 15 16 17 18 19 10 11 12 13 14 15 16 16 17 18 19 20 21 22 20 21 22 23 24 25 26 20 21 22 23 24 25 26 17 18 19 20 21 22 23 23 24 25 26 27 28 29 27 28 27 28 29 30 31 24 25 26 27 28 29 30 30 31 May June July Aug. s M TWTFS s MTWTFS s MT W T F SS M TW T FS 1 2 3 4 5 6 7 1 234 12 123456 8 9 10 11 12 13 14 5 6 7 8 9 10 11 3 . 4 5 6 7 8 9 7 8 9 10 11 12 13 15 16 17 18 19 20 21 12 13 14 15 16 17 18 10 11 12 13 14 15 16 14 15 16 17 18 19 20 22 23 24 25 26 27 28 19 20 21 22 23 24 25 17 18 19 20 21 22 23 21 22 23 24 25 26 27 29 30 31 26 27 28 29 30 24 25 26 27 28 29 30 28 29 30 31 31 Sept. O c t Nov. Dec. SM TW TFS s MT W TFS SMTWTFS s MTWT FS 1 2 3 1 1 2 3 4 5 1 2 3 4 . 5 6 7 8 9 10 2 3 4 5 6 *7 8 6 7 8 9 10 11 12 4 . 5 6 7 8 9 10 11 12 13 14 15 16 17 9 10 11 12 13 14 15 13 14 15 16 17 18 19 11 12 13 14 15 16 17 18 19 20 21 22 23 24 16 17 18 19 20 21 22 20 21 22 23 24 25 26 18 19 20 21 22 23 24 25 26 27 28 29 30 23 24 25 26 27 28 29 27 28 29 30 25 26 27 28 29 30 31 30 31 BUILD YOUR OWN TELESCOPE! Kits for Building your own Telescope. Accessories—Rack & Pinions, Eyepieces, Prisms, Prism Holders, Cells, Lenses, and Tubing. Finished Parabolic and Spherical Mirrors also Mirrors Ground to order. Complete Aluminizing Facilities. FREE CATALOG — INSTRUCTIONS 10 CENTS GARTH OPTICAL CO. G.P.O. BOX 954, NEW YORK 1, N.Y. THE OBSERVER’S HANDBOOK FOR 1955 PUBLISHED BY The Royal Astronomical Society of Canada C. A. CHANT, E ditor RUTH J. NORTHCOTT, A s s is t a n t E ditor DAVID DUNLAP OBSERVATORY FORTY-SEVENTH YEAR OF PUBLICATION P rice 50 C e n t s TORONTO 13 Ross S t r e e t Printed for the Society By the University of Toronto Press CONTENTS PAGE C a l e n d a r ...................................................................................Cover p. ii Preface 3 Anniversaries and F e s t iv a ls ......................................................................3 Symbols and A bbreviations......................................................................4 The Constellations......................................................................................... 5 Miscellaneous Astronomical D a t a ............................................................6 Ephemeris of the Su n ............................................................................... 7 Solar and Sidereal Time ------- - 8 Julian Day C a l e n d a r ............................................................................... 9 Map of Standard Time Z o n e s......................................................................9 Times of Sunrise and S u n s e t ....................................................................10 Times of Beginning and Ending of Twilight 17 Times of Moonrise and M o o n s e t .......................................................... 18 The Planets for 1955 24 Eclipses, 1955 --------- 29 The Sky and Astronomical Phenomena Month by Month - - 30 Phenomena of Jupiter’s S a te llite s ..........................................................54 Lunar Occultations, 1955 56 Ephemeris for the Physical Observation of the Sun 57 Principal Elements of the Solar S y s t e m ................................................ 58 Satellites of the Solar S y stem ....................................................................59 Fields for Bright Variable S t a r s ..........................................................60 Representative Bright Variable Stars - - - - - 61 Double and Multiple Stars, with a short list 62 The Brightest Stars, their magnitudes, types, proper motions, distances and radial velocities..........................................................64 Clusters and Nebulae: Star C lu sters....................................................................................... 72 Galactic N e b u la e ............................................................................. 73 Extra-Galactic N e b u la e ....................................................................74 Four Circular Star M a p s ....................................................................75 TABLES IN RECENT OBSERVER’S HANDBOOKS Distance of the Stars—the Sun’s Neighbours - 1941 Messier’s List of Clusters and N e b u la e ............................................ 1942 Meteorological Data: European and Asiatic - 1942 Canada and United States - 1946 List of Air Navigation S t a r s ................................................................1947 Table of Precession for 50 Y e a r s ......................................................1951 PRINTED IN CANADA PREFACE The H a n d b o o k for 1955 is the 47th issue and its circulation is 5500. The Officers of the Society appreciate the increase in advertisements which will help to meet our mounting expense. In this issue the tables of the principal elements of the solar system have been revised. Four circular star maps 9 inches in diameter at a price of two cents each and a set of four maps plotted on equatorial co-ordinates at a price of twenty cents are obtainable from the Director of University Extension, University of Toronto. Toronto 5. Celestial distances given herein are based on the standard value of 8".80 for the sun’s parallax, not on the more recent value 8".790 determined by Sir Harold Jones; and the calculations for Algol are based on Olin J. Eggen’s epoch 2432520.6303 and period 2.86731525 d., as published in the Astrophysical Journal, 1948. Cordial thanks are tendered to those who assisted in preparing this volume, especially to the staff of the David Dunlap Observatory, and also Miss Olga Mracek, John Crawford, Basil Kerr, Malcolm Lennox, Donald Morton and Ghislain Roy. Our deep indebtedness to the British Nautical Almanac and the American Ephemeris is thankfully acknowledged. C . A . C h a n t David Dunlap Observatory, Richmond Hill, Ont., October 1954. ANNIVERSARIES AND FESTIVALS, 1955 New Y ear’s Day Sat. Jan. 1 Trinity Sunday............................ June 5 E piphany ........................Thu. Jan. 6 Corpus Christi................Thu. June 9 Accession of Queen St. John Baptist (Mid­ Elizabeth (1952). .Sun. Feb. 6 summer Day) Fri. June 24 Septuagesima Sunday Feb. 6 Dominion Day ...............Fri. July 1 Quinquagesima (Shrove Birthday of Queen Mother Sunday) Feb. 20 Elizabeth (1900).... Thu. Aug. 4 Ash Wednesday Feb. 23 Labour D a y .....................Mon. Sept. 5 St. D av id ........................Tue. Mar. 1 Hebrew New Year St. Patrick ......................Thu. Mar. 17 (Rosh Hashanah) ... Sat. Sept. 17 Palm Sunday Apr. 3 St. Michael Good Friday .................. Fri. Apr. 8 (Michaelmas Day) . .Thu. Sept. 29 Easter Sunday Apr. 10 All Saints’ Day ...............Tue. Nov. 1 Birthday of Queen Remembrance Day. .. .Fri. Nov. 11 Elizabeth (1926). .Thu. Apr. 21 First Sunday in Advent.............Nov. 27 St. George.......................Sat. Apr. 23 St. A ndrew ...................... Wed. Nov. 30 Rogation Sunday May 15 Christmas Day ...Sun. Dec. 25 Ascension Day .............. Thu. May 19 Empire Day (Victoria D a y )............................ Tue. May 24 Thanksgiving Day, date Pentecost (Whit Sunday) May 29 set by Proclamation SYMBOLS AND ABBREVIATIONS SIGNS OF THE ZODIAC SUN, MOON AND PLANETS ASPECTS AND ABBREVIATIONS & Conjunction, or having the same Longitude or Right Ascension <P Opposition, or differing 180° in Longitude or Right Ascension □ Quadrature, or differing 90° in Longitude or Right Ascension 9> Ascending Node; U Descending Node. α or A. R ., Right Ascension; δ Declination, h, m, s. Hours, Minutes, Seconds of Time. ° ' Degrees, Minutes, Seconds of Arc.