The Ages of Early-Type Stars: Str\" Omgren Photometric Methods
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Binocular Universe: You're My Hero! December 2010
Binocular Universe: You're My Hero! December 2010 Phil Harrington on't you just love a happy ending? I know I do. Picture this. Princess Andromeda, a helpless damsel in distress, chained to a rock as a ferocious D sea monster loomed nearby. Just when all appeared lost, our hero -- Perseus! -- plunges out of the sky, kills the monster, and sweeps up our maiden in his arms. Together, they fly off into the sunset on his winged horse to live happily ever after. Such is the stuff of myths and legends. That story, the legend of Perseus and Andromeda, was recounted in last month's column when we visited some binocular targets within the constellation Cassiopeia. In mythology, Queen Cassiopeia was Andromeda's mother, and the cause for her peril in the first place. Left: Autumn star map from Star Watch by Phil Harrington Above: Finder chart for this month's Binocular Universe. Chart adapted from Touring the Universe through Binoculars Atlas (TUBA), www.philharrington.net/tuba.htm This month, we return to the scene of the rescue, to our hero, Perseus. He stands in our sky to the east of Cassiopeia and Andromeda, should the Queen's bragging get her daughter into hot water again. The constellation's brightest star, Mirfak (Alpha [α] Persei), lies about two-thirds of the way along a line that stretches from Pegasus to the bright star Capella in Auriga. Shining at magnitude +1.8, Mirfak is classified as a class F5 white supergiant. It radiates some 5,000 times the energy of our Sun and has a diameter 62 times larger. -
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. -
Proper Motion Surveys of the Young Open Clusters Alpha Persei and the Pleiades
A&A 416, 125–136 (2004) Astronomy DOI: 10.1051/0004-6361:20034238 & c ESO 2004 Astrophysics Proper motion surveys of the young open clusters Alpha Persei and the Pleiades N. R. Deacon and N. C. Hambly Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK Received 28 August 2003 / Accepted 28 October 2003 Abstract. In this paper we present surveys of two open clusters using photometry and accurate astrometry from the SuperCOSMOS microdensitometer. These use plates taken by the Palomar Oschin Schmidt Telescope giving a wide field (5◦ from the cluster centre in both cases), accurate positions and a long time baseline for the proper motions. Distribution functions are fitted to proper motion vector point diagrams yielding formal membership probabilities. Luminosity and mass functions are then produced along with a catalogue of high probability members. Background star contamination limited the depth of the study of Alpha Per to R = 18. Due to this the mass function found for this cluster could only be fitted with a power ξ = −α α = . +0.14 law ( (m) m ) with 0 86−0.19. However with the better seperation of the Pleiades’ cluster proper motion from the field population results were obtained down to R = 21. As the mass function produced for this cluster extends to lower masses it is possible to see the gradient becoming increasingly shallow. This mass function is well fitted by a log normal distribution. Key words. astrometry – stars: low mass, brown dwarfs – Galaxy: open clusters and associations: individual: Alpha Per, Pleiades 1. Introduction Most recently Barrado y Navascu´es et al. -
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
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. -
Keck Spectra of Brown Dwarf Candidates and a Precise
TABLE 1 Summary of Optical Imaging for Alpha Persei Telescope Area Covered Limiting Magnitude (sq.degrees) (R/I) CWRU Schmidt 3.2 21.5/20.5 MHO 1.2m 1.1 22.0/20.7 KPNO 0.9m 0.5 21.5/20.5 KPNO 4.0m 1.3 22.4/21.0 KPNO 4.0m a (2.5) ≈ 24/≈ 23 aBouvier et al. (1999) TABLE 2 Photometry of Alpha Persei Stars Star α(J2000) δ(J2000) Ic R − Ic K Ic − K AP300 3 17 27.6 49 36 53.0 17.85 2.18 14.62 3.23 AP301 3 18 09.2 49 25 19.0 17.75 2.22 14.14 3.61 AP302 3 19 08.4 48 43 48.5 17.63 2.08 ······ AP303 3 19 10.9 48 42 20.0 16.98 1.88 ······ AP304 3 19 13.2 48 31 55.0 18.83 2.40 ······ AP305 3 19 21.7 49 23 32.0 18.48 2.34 ······ AP306 3 19 41.8 50 30 42.0 18.40 2.34 14.9 3.5 AP307 3 20 20.9 48 01 05.0 17.08 2.01 ······ AP308 3 20 59.7 48 18 37.0 16.71 1.89 ······ AP309 3 22 40.6 48 00 36.0 16.57 1.88 ······ AP275 a 3 23 03.3 48 53 07.0 17.25 2.20 ······ AP310 3 23 04.7 48 16 13.0 17.80 2.33 14.55 3.25 AP311 3 23 08.4 48 04 52.5 17.70 2.12 14.30 3.40 AP312 3 23 14.8 48 11 56.0 18.60 2.41 15.21 3.39 AP313 3 24 08.1 48 48 30.0 17.55 2.13 ······ AP314 3 25 19.6 49 17 58.0 18.20 2.26 15.15 3.05 AP315 3 26 34.5 49 07 46.0 18.20 2.34 14.80 3.40 arXiv:astro-ph/9909207v2 15 Sep 1999 AP316 3 27 01.3 49 14 40.0 17.75 2.18 14.48 3.27 AP317 3 28 06.0 48 45 13.5 17.85 2.29 15.0 2.85 AP318 3 30 42.5 48 21 27.0 17.45 2.16 14.10 3.35 AP319 3 31 03.2 49 02 58.0 16.89 1.95 ······ AP320 3 31 25.3 49 02 52.0 16.79 1.90 ······ AP321 3 32 18.7 49 32 18.0 17.75 2.20 ······ AP322 3 33 08.3 49 37 56.5 17.60 2.14 14.57 3.03 AP323 3 33 20.7 48 45 51.0 17.50 2.13 14.33 3.17 AP324 3 33 48.2 48 52 30.5 18.10 2.36 14.68 3.42 AP325 3 35 47.2 49 17 43.0 17.65 2.30 14.14 3.51 AP326 3 38 55.2 48 57 31.0 18.70 2.40 15.09 3.61 aAP275 is from Prosser (1994). -
December 2019 BRAS Newsletter
A Monthly Meeting December 11th at 7PM at HRPO (Monthly meetings are on 2nd Mondays, Highland Road Park Observatory). Annual Christmas Potluck, and election of officers. What's In This Issue? President’s Message Secretary's Summary Outreach Report Asteroid and Comet News Light Pollution Committee Report Globe at Night Member’s Corner – The Green Odyssey Messages from the HRPO Friday Night Lecture Series Science Academy Solar Viewing Stem Expansion Transit of Murcury Edge of Night Natural Sky Conference Observing Notes: Perseus – Rescuer Of Andromeda, or the Hero & Mythology Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 25 December 2019 President’s Message I would like to thank everyone for having me as your president for the last two years . I hope you have enjoyed the past two year as much as I did. We had our first Members Only Observing Night (MOON) at HRPO on Sunday, 29 November,. New officers nominated for next year: Scott Cadwallader for President, Coy Wagoner for Vice- President, Thomas Halligan for Secretary, and Trey Anding for Treasurer. Of course, the nominations are still open. If you wish to be an officer or know of a fellow member who would make a good officer contact John Nagle, Merrill Hess, or Craig Brenden. We will hold our annual Baton Rouge “Gastronomical” Society Christmas holiday feast potluck and officer elections on Monday, December 9th at 7PM at HRPO. I look forward to seeing you all there. ALCon 2022 Bid Preparation and Planning Committee: We’ll meet again on December 14 at 3:00.pm at Coffee Call, 3132 College Dr F, Baton Rouge, LA 70808, UPCOMING BRAS MEETINGS: Light Pollution Committee - HRPO, Wednesday December 4th, 6:15 P.M. -
Sky at Night 55 Moore Marathon - Observing Guide
The Sky at Night 55 Moore Marathon - Observing Guide... Thanks for taking part in the Sky at Night’s Moore Marathon - our 55th anniversary challenge. This guide has been designed to help you fi nd the 55 selected objects in the marathon. We would like you to tell us which of our 55 selected objects you’ve managed to fi nd. If you’ve managed to grab any images of them, then you can share them via our Flickr group at... www.fl ickr.com/groups/bbcskyatnight Remember too that you can keep up with the programme itself at... www.bbc.co.uk/skyatnight The guide has been written for the month of April, when British Summer Time is in force. When we talk about time in the marathon, we mean British Summer Time (BST) - that’s the same time as shown on your clock or watch. BST comes into force during 2012 on March 25th. On this day the clocks go forward by one hour. Please remember that for programme inclusion, we need your completed QUICK or DETAILED forms back by April 24th. Object No. Guide Page Object No. Guide Page Object No. Guide Page 1 2 21 4 41 4 2 2 22 11 42 4 3 2 23 15 43 2 4 2 24 15 44 8 5 4 25 4 45 9 6 4 26 11 46 9 7 8 27 14 47 9 8 8 28 14 48 9 9 8 29 14 49 4 10 4 30 9 50 2 11 4 31 15 51 4 12 9 32 11 52 15 13 10 33 4 53 15 14 10 34 13 54 13 15 10 35 2 55 11 16 10 36 4 17 13 37 2 18 11 38 4 19 14 39 4 20 13 40 11 Page 1 1 The Moon Rating - Easy Best seen with - Naked Eye Visibility - 1-9 April before midnight, 10-17 early hours, 22-30 early evening (programme deadline 24th April) The fi rst object is our very own Moon. -
Algol As Horus in the Cairo Calendar: the Possible Means and the Motives of the Observations
Open Astron. 2018; 27: 232–263 Research Article Sebastian Porceddu*, Lauri Jetsu, Tapio Markkanen, Joonas Lyytinen, Perttu Kajatkari, Jyri Lehtinen, and Jaana Toivari-Viitala Algol as Horus in the Cairo Calendar: the possible means and the motives of the observations https://doi.org/10.1515/astro-2018-0033 Received Feb 15, 2018; accepted May 04, 2018 Abstract: An ancient Egyptian Calendar of Lucky and Unlucky Days, the Cairo Calendar (CC), assigns luck with the period of 2.850 days. Previous astronomical, astrophysical and statistical analyses of CC support the idea that this was the period of the eclipsing binary Algol three millennia ago. However, next to nothing is known about who recorded Algol’s period into CC and especially how. Here, we show that the ancient Egyptian scribes had the possible means and the motives for such astronomical observations. Their principles of describing celestial phenomena as activity of gods reveal why Algol received the title of Horus Keywords: Algol, Horus, ancient Egyptian Astronomy, variable stars, the Cairo Calendar, hemerologies 1 Introduction ies (Porceddu et al., 2008; Jetsu et al., 2013; Jetsu and Porceddu, 2015), we use only the best preserved continuous calendar which is found on pages recto III-XXX and verso The ancient Egyptian texts known as the Calendars of I-IX of papyrus Cairo 86637.The other texts and fragments Lucky and Unlucky Days, or hemerologies, are literary contained in the same papyrus are ignored from this analy- works that assign prognoses to each day of the Egyp- sis because the connection of these fragments to the main tian year (Wells, 2001a, p117-118), (Leitz, 1994, p1-2) (Bacs, calendar is not apparent and we do not know what year 1990, p41-45) (Troy, 1989, p127-147) and (Helck et al., 1975– they describe, so combining any data points from these 1992, p156). -
Astronomy Magazine 2012 Index Subject Index
Astronomy Magazine 2012 Index Subject Index A AAR (Adirondack Astronomy Retreat), 2:60 AAS (American Astronomical Society), 5:17 Abell 21 (Medusa Nebula; Sharpless 2-274; PK 205+14), 10:62 Abell 33 (planetary nebula), 10:23 Abell 61 (planetary nebula), 8:72 Abell 81 (IC 1454) (planetary nebula), 12:54 Abell 222 (galaxy cluster), 11:18 Abell 223 (galaxy cluster), 11:18 Abell 520 (galaxy cluster), 10:52 ACT-CL J0102-4915 (El Gordo) (galaxy cluster), 10:33 Adirondack Astronomy Retreat (AAR), 2:60 AF (Astronomy Foundation), 1:14 AKARI infrared observatory, 3:17 The Albuquerque Astronomical Society (TAAS), 6:21 Algol (Beta Persei) (variable star), 11:14 ALMA (Atacama Large Millimeter/submillimeter Array), 2:13, 5:22 Alpha Aquilae (Altair) (star), 8:58–59 Alpha Centauri (star system), possibility of manned travel to, 7:22–27 Alpha Cygni (Deneb) (star), 8:58–59 Alpha Lyrae (Vega) (star), 8:58–59 Alpha Virginis (Spica) (star), 12:71 Altair (Alpha Aquilae) (star), 8:58–59 amateur astronomy clubs, 1:14 websites to create observing charts, 3:61–63 American Astronomical Society (AAS), 5:17 Andromeda Galaxy (M31) aging Sun-like stars in, 5:22 black hole in, 6:17 close pass by Triangulum Galaxy, 10:15 collision with Milky Way, 5:47 dwarf galaxies orbiting, 3:20 Antennae (NGC 4038 and NGC 4039) (colliding galaxies), 10:46 antihydrogen, 7:18 antimatter, energy produced when matter collides with, 3:51 Apollo missions, images taken of landing sites, 1:19 Aristarchus Crater (feature on Moon), 10:60–61 Armstrong, Neil, 12:18 arsenic, found in old star, 9:15 -
December 2020
the vol. 47 no. 12 Skyscraper December 2020 AMATEUR ASTRONOMICAL SOCIETY OF RHODE ISLAND 47 PEEPTOAD ROAD NORTH SCITUATE, RHODE ISLAND 02857 WWW.THESKYSCRAPERS.ORG In This Issue: A Guide to Collecting Meteorites 2 New Problems for Radio A Presentation by Gregory Shanos Astronomy: The Rise of Starlink and the Loss of Arecibo Saturday, December 5, 7:0opm EST via Zoom 3 The Geminid Meteor Shower Contact Steve Hubbard ([email protected]) for and the Great Conjunction of Zoom Meeting link and information. Jupiter & Saturn 5 Planetary Nebula in Perseus: Greg Shanos is a pharmacist by profes- Messier 76 sion and amateur astronomer by passion. It all began with the apparition of Halley’s Upcoming 6 NASA Night Sky Notes: Visitors Comet in 1985-1986 when Greg became a Presentations to Both Jupiter and Saturn member of Skyscrapers and subscribed to Sky & Telescope/Astronomy magazines. Saturday, January 2 7 The Sun, Moon & There he found an ad for Robert Haag Me- Mike Wenz: A Behind The Planets in December teorites. After receiving the catalog, Greg Scenes Look At The Hubble purchased three iron meteorites, and Telescope 8 Star Party Update from that point on his passion for these 9 Astrophoto Gallery extraterrestrial gems was ignited. Over Saturday, February 6 thirty years later, Greg continues to col- John Briggs: A Walking Tour 14 Starry Scoop lect, lecture, and educate about the won- of Optical History - Artifacts ders of these rocks from space. Greg has and Anecdotes from the also published over 35 review articles in Astronomical Lyceum Meteorite & Meteorite-Times magazines regarding organic compounds in meteor- Saturday, March 6 Seagrave Observatory is ites. -
1958Apj. . .128 . .185C TWO-DIMENSIONAL SPECTRAL CLASSIFICATION by NARROW-BAND PHOTOMETRY for B STARS in CLUSTERS and ASSOCIATIO
.185C . .128 TWO-DIMENSIONAL SPECTRAL CLASSIFICATION BY NARROW-BAND . PHOTOMETRY FOR B STARS IN CLUSTERS AND ASSOCIATIONS* David L. Crawford 1958ApJ. Yerkes and McDonald Observatories Received May 6, 1958 ABSTRACT Photoelectric observations of the intensity of the Hß line have been made with the 36-inch reflector of the McDonald Observatory for B stars with available MK spectral types and for B stars in several clusters and associations. The various filter systems used are discussed, and the measures are transformed to a standard system. The color index (U—B) of the U, B, V system, when corrected for interstellar reddening, is used with the Hß intensities to define a two-dimensional spectral classification system Evolutionary effects on this classification system are discussed, and relative ages for the Scorpio-Cen- taurus cluster, the Orion association, the f Persei association, the a Persei cluster, and. the field stars are estimated. Mean absolute magnitudes are computed for the B8 V and B9 V stars in the Scorpio- Centaurus cluster, and a comparison with the a Persei cluster yields a minimum distance modulus for it of 6 4 mag I. INTRODUCTION Most of the current investigations on luminosity determinations for B stars have used either visual two-dimensional spectral classification, such as the MK system, or photographic determinations of hydrogen-line intensities, together with some type of estimates for spectral type. These methods have given fundamental results in galactic structure and other fields of astronomy. However, the success of narrow-band photome- try for the F stars by B. Strömgren suggests that such methods would be quite useful for the B stars as well. -
Transits of Mercury, 1605–2999 CE
Appendix A Transits of Mercury, 1605–2999 CE Date (TT) Int. Offset Date (TT) Int. Offset Date (TT) Int. Offset 1605 Nov 01.84 7.0 −0.884 2065 Nov 11.84 3.5 +0.187 2542 May 17.36 9.5 −0.716 1615 May 03.42 9.5 +0.493 2078 Nov 14.57 13.0 +0.695 2545 Nov 18.57 3.5 +0.331 1618 Nov 04.57 3.5 −0.364 2085 Nov 07.57 7.0 −0.742 2558 Nov 21.31 13.0 +0.841 1628 May 05.73 9.5 −0.601 2095 May 08.88 9.5 +0.326 2565 Nov 14.31 7.0 −0.599 1631 Nov 07.31 3.5 +0.150 2098 Nov 10.31 3.5 −0.222 2575 May 15.34 9.5 +0.157 1644 Nov 09.04 13.0 +0.661 2108 May 12.18 9.5 −0.763 2578 Nov 17.04 3.5 −0.078 1651 Nov 03.04 7.0 −0.774 2111 Nov 14.04 3.5 +0.292 2588 May 17.64 9.5 −0.932 1661 May 03.70 9.5 +0.277 2124 Nov 15.77 13.0 +0.803 2591 Nov 19.77 3.5 +0.438 1664 Nov 04.77 3.5 −0.258 2131 Nov 09.77 7.0 −0.634 2604 Nov 22.51 13.0 +0.947 1674 May 07.01 9.5 −0.816 2141 May 10.16 9.5 +0.114 2608 May 13.34 3.5 +1.010 1677 Nov 07.51 3.5 +0.256 2144 Nov 11.50 3.5 −0.116 2611 Nov 16.50 3.5 −0.490 1690 Nov 10.24 13.0 +0.765 2154 May 13.46 9.5 −0.979 2621 May 16.62 9.5 −0.055 1697 Nov 03.24 7.0 −0.668 2157 Nov 14.24 3.5 +0.399 2624 Nov 18.24 3.5 +0.030 1707 May 05.98 9.5 +0.067 2170 Nov 16.97 13.0 +0.907 2637 Nov 20.97 13.0 +0.543 1710 Nov 06.97 3.5 −0.150 2174 May 08.15 3.5 +0.972 2644 Nov 13.96 7.0 −0.906 1723 Nov 09.71 13.0 +0.361 2177 Nov 09.97 3.5 −0.526 2654 May 14.61 9.5 +0.805 1736 Nov 11.44 13.0 +0.869 2187 May 11.44 9.5 −0.101 2657 Nov 16.70 3.5 −0.381 1740 May 02.96 3.5 +0.934 2190 Nov 12.70 3.5 −0.009 2667 May 17.89 9.5 −0.265 1743 Nov 05.44 3.5 −0.560 2203 Nov