THE GALACTIC GAZETTE The Astronomical Society of Southern New England Next Meeting
Transcription
THE GALACTIC GAZETTE The Astronomical Society of Southern New England Next Meeting
ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 THE GALACTIC GAZETTE THE NEWSLETTER OF The Astronomical Society of Southern New England “To Educate and Inspire” http://assne.org Next Meeting Club Officers for 2014-2016 Bruce DiDucca Tom Hannigan George Huftalen Spence Blakely October 11, 2014 7 p.m Carpenter Museum 4 Locust Ave. Rehoboth, Mass. Doors open at 6 p.m. President Vice President Treasurer Secretary This month’s feature Rehoboth Skies 2014 and Alan Hirshfeld presents: From Backyard to Mountaintop: The Three Lives of History's Best Worst Telescope Letters to ASSNE To submit your comments or questions of general interest about ASSNE or to learn more about our public outreach programs, please send an email to ASSNE Secretary. Please direct personal club-related business or concerns to the appropriate club officer. News & Announcements Content may be edited for clarity. New book by Alan Hirshfeld Alan will give a presentation at the meeting, based on his his new book Starlight Detectives: How Astronomers, Inventors, and Eccentrics Discovered the Modern Universe. The book will be available, for $20, with profits going page 1 of 17 to the UMass Dartmouth Observatory. About the book A wondrous tale of cosmic exploration and the colorful characters who ushered astronomy into the modern age ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 In 1929, Edwin Hubble announced the greatest discovery in the history of astronomy since Galileo first turned a telescope to the heavens. The galaxies, previously believed to float serenely in the void, are in fact hurtling apart at an incredible speed: the universe is expanding. This stunning discovery was the culmination of a decades-long arc of scientific and technical advancement. In its shadow lies an untold, yet equally fascinating, backstory whose cast of characters illuminates the gritty, hard-won nature of scientific progress. The path to a broader mode of cosmic observation was blazed by a cadre of nineteenth-century amateur astronomers and inventors, galvanized by the advent of photography, spectral analysis, and innovative technology to create the entirely new field of astrophysics. From William Bond, who turned his home into a functional observatory, to John and Henry Draper, a father and son team who were trailblazers of astrophotography and spectroscopy, to geniuses of invention such as Léon Foucault, and George Hale, who founded the Mount Wilson Observatory, Hirshfeld reveals the incredible stories—and the ambitious dreamers—behind the birth of modern astronomy. Praise for Starlight Detectives “Starlight Detectives is just the sort of richly veined book I love to read—full of scientific history and discoveries, peopled by real heroes and rogues, and told with absolute authority. Alan Hirshfeld’s wide, deep knowledge of astronomy arises not only from the most careful scholarship, but also from the years he’s spent at the telescope, posing his own questions to the stars.”—DAVA SOBEL, author of Longitude and A More Perfect Heaven “Beautifully written, Starlight Detectives reminds us how the wonders of the modern universe would never have been possible without the ingenious advances made by pioneering scientists in the nineteenth century. They were the ones who first learned how to read the messages hidden within a star’s radiations. With his poetic eye on the nighttime sky, Alan Hirshfeld engagingly shows how science arrived, step by step, at its revolutionary discovery that we live in but one galaxy amid multitudes flying outward in an expanding universe. A must-read for astronomy and history of science aficionados alike.”—MARCIA BARTUSIAK, author of The Day We Found the Universe and Archives of the Universe “A delightful, detailed chronicle of great men (and a rare woman) whose fas- page 2 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! cination with the night sky and the technology necessary to study it led to today’s dramatic discoveries.”—Kirkus Reviews (Starred review) "Hirshfeld tells this climactic discovery of the expanding universe with great verve and sweep, as befits a story whose scope, characters and import leave most fiction behind."—Wall Street Journal "Hirshfeld sums it up: The classical astronomer's question, Where is a star? evolved into the astrophysicist's more profound inquiry, What is a star?"— Boston Globe “A masterful balance of science, history and rich narrative.”—Discover magazine (“Top 5 Summer Read”) “From 1850 to 1930, a handful of technological adepts transformed astronomy. That race to see deep space is told with palpable relish by physicist Alan Hirshfeld.”—Nature “A well-written and enjoyable title for astronomers—professional and amateur alike—as well as science history fans.”—Library Journal “Far from a dry scientific text, the book contains prose that is light even when didactic, engaging in its personification of these unjustly forgotten astronomers as determined, obsessed, stalwart, and sometimes just plain strange. Every researcher presented in this book is as lively in the text as if they were still personally scouring the heavens.”— Foreword Reviews "Hirshfeld chronicles the radical changes in our conception of the cosmos that have accompanied the advent of ! ! ! ! October 2014 modern astronomy over the past century and a half. Recommended."—Scientific American “Tales of pioneering skywatchers and their discoveries in the 19th century show how modern astronomy was born.”—Science News “Alan Hirshfeld’s wonderful Starlight Detectives is a tour-de-force synthesis of the historic and scientific factors relating 19th century photography, astronomy, and spectroscopy. … Hirshfeld’s writing style brings the 19th century back to life and provides a rich tapestry of astronomical history. ”—American Journal of Physics “Writing this book would ideally require an author with an extensive knowledge of astronomy, including astronomical instruments, a deep understanding of the ways of thought of astronomers, a broad range of historical knowledge, and an exceptional skill at making astronomical ideas clear and engaging. Alan Hirshfeld possesses all of these skills. His Starlight Detectives is remarkable.”—MICHAEL C. CROWE, author of The Extraterrestrial Life Debate, 1750–1900 “Hirshfeld documents how the practice of astronomy changed between 1840 and 1940 thanks to innovative pioneers whose efforts made it possible to capture and preserve otherwise faint and fleeting images, and to decipher the cryptographic messages found in the light of celestial bodies. His riveting narrative brings to life their challenges, failures, and successes. It will captivate all who have observed the night sky.”— BARBARA J. BECKER, author of Unravel- page 3 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! ling Starlight: William and Margaret Huggins and the Rise of the New Astronomy “A thrilling historical account of the rise of astrophysics, the early years of astronomical photography and spectroscopy, and the innovations that transformed the astronomical telescope in the nineteenth century. Alan Hirshfeld’s thoroughly researched narrative is accessible, entertaining, and scholarly, and includes many pioneers who have been overlooked until now. I greatly admire this outstanding contribution to the history of astronomy.”—SIMON MITTON, co-author of Heart of Darkness: Unraveling the Mysteries of the Invisible Universe and author of Fred Hoyle: A Life in Science About the Author Alan Hirshfeld, Professor of Physics at the University of Massachusetts Dartmouth and an Associate of the Harvard College Observatory, is the author of Parallax: The Race to Measure the Cosmos, The Electric Life of Michael Faraday, and Eureka Man: The Life and Legacy of Archimedes. He is a regular book reviewer for the Wall Street Journal and has contributed to Sky & Telescope, the American Journal of Physics, BBC History Magazine, and American Scientist. He has made radio and television appearances on NPR, PBS, and C-SPAN and lectures nationwide about science history and discovery. New Members ASSNE welcomes returning members Alan Harris & family. page 4 of 17 ! ! ! October 2014 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 Calendar of Events Your support at these events is greatly appreciated. Even if you don’t own a scope, you are always welcome to drop by to lend a hand and show your enthusiasm. You may be surprised at how much fun you can have. ASSNE thanks Rebekah Bartlett for the Club Event Listings. ASSNE events Other events Club Event Listings TBA ASSNE Members’ Advice and Help Galileo's Gabfest Observing Reports and Astro Images Observing is often more enjoyable if it is a shared experience. Everyone benefits from the exchange of knowledge, tips, and camaraderie. Several ASSNE members observe regularly and send out emailed invitations to those requesting them. If you would like to receive such invitations from someone living near you, please contact a club officer. Visitors to this site who just want to see what it’s all about should also contact an officer. Informal Observing Sessions Current Observing Reports The Imager's Studio page 5 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 For Sale and Wanted ASSNE Trading Post Club Loaner Telescopes The following telescopes and accessories are available to qualifying members for one-month loans. If you are interested, contact Bruce DiDucca beforehand, so he can arrange to have the one you want at the meeting. For more information about an item or to check availability, go to Loaner Equipment. ASSNE thanks the generous donors. ✯ Meade 8-inch LX-200 GPS Schmidt-Cassegrain (donated by Frank Gosland) ✯ Meade 80 mm, f/5, refractor ✯ Edmund Astroscan rich-field reflector. ✯ Coronado PST solar telescope ✯ Meade Digi Eyepiece (donated by Paul Faria) ✯ Astrovid Stellacam (donated by Wayne Prado) ✯ Laser collimator (donated by Ed Couture) Astro Links For Kids: Why did it take so long to discover Uranus? Gravitational wave discovery gives way to Milky Way dust Greg Stone’s Prime Time for October page 6 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 Twinkle, twinkle, variable star by Dr. Ethan Siegel As bright and steady as they appear, the stars in our sky won't shine forever. The steady brilliance of these sources of light is powered by a tumultuous interior, where nuclear processes fuse light elements and isotopes into heavier ones. Because the heavier nuclei up to iron (Fe), have a greater binding energies-per-nucleon, each reaction results in a slight reduction of the star's mass, converting it into energy via Einstein's famous equation relating changes in mass and energy output, E = mc2. Over timescales of tens of thousands of years, that energy migrates to the star's photosphere, where it's emitted out into the universe as starlight. Images credit: NASA's Galaxy Evolution Explorer (GALEX) spacecraft, of Mira and its tail in UV light (top); Margarita Karovska (Harvard-Smithsonian CfA) / NASA's Hubble Space Telescope image of Mira, with the distortions revealing the presence of a binary companion (lower left); public domain image of Orion, the Pleiades and Mira (near maximum brightness) by Brocken Inaglory of Wikimedia Commons under CC-BY-SA-3.0 (lower right). There's only a finite amount of fuel in there, and when stars run out, the interior contracts and heats up, often enabling heavier elements to burn at even higher temperatures, and causing sun-like stars to grow into red giants. Even though the cores of both hydrogen-burning and helium-burning stars have consistent, steady energy outputs, our sun's overall brightness varies by just ~0.1%, while red giants can have their brightness’s vary by factors of thousands or more over the course of a single year! In fact, the first periodic or pulsating variable star ever discovered—Mira (omicron Ceti)—behaves exactly in this way. There are many types of variable stars, including Cepheids, RR Lyrae, cataclysmic variables and more, but it's the Mira-type variables that give us a glimpse into our Sun's likely future. In general, the cores of stars burn through their fuel in a very consistent fashion, but in the case of pulsating variable stars the outer layers of stellar atmospheres vary. Initially heating up and expanding, they overshoot equilibrium, reach a page 7 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! maximum size, cool, then often forming neutral molecules that behave as lightblocking dust, with the dust then falling back to the star, ionizing and starting the whole process over again. This temporarily neutral dust absorbs the visible light from the star and re-emits it, but as infrared radiation, which is invisible to our eyes. In the case of Mira (and many red giants), it's Titanium Monoxide (TiO) that causes it to dim so severely, from a maximum magnitude of +2 or +3 (clearly visible to the naked eye) to a minimum of +9 or +10, requiring a telescope (and an experienced observer) to find! Visible in the constellation of Cetus during the fall-and-winter from the Northern Hemisphere, Mira is presently at magnitude +7 and headed towards its minimum, but will reach its maximum brightness again in May of next year and every 332 days thereafter. Shockingly, Mira contains a huge, 13 light-year-long tail -- visible only in the UV -- that it leaves as it rockets through the interstellar medium at 130 km/sec! Look for it in your skies all winter long, and contribute your results to the AAVSO (American Association of Variable Star Observers) International Database to help study its long-term behavior! Check out some cool images and simulated animations of Mira here: http://www.nasa.gov/mission_pages/galex/ 20070815/v.html Kids can learn all about Mira at NASA’s Space Place: http://spaceplace.nasa.gov/mira/en/ page 8 of 17 ! ! ! October 2014 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 AAVSO Writers’ Bureau Welcome to the AAVSO Writers’ Bureau Blog. Here we have collected, from our talented and gracious partners, some of the finest content available on the Internet each month. These writers have given explicit permission for these articles to be reprinted on other websites and newsletters. Dating a Star ... a Few Hundred Thousand, in Fact by Phil Plait, Bad Astronomy Globular clusters are too cool. For one thing, they’re gorgeous. I have proof! That is IC 4499, a tight ball of tens or hundreds of thousands of stars located roughly 60,000 light years away. This image was taken by Hubble, and besides being spectacular, it also was used to nail down the age of the cluster, which until recently has been a bit controversial. This is another reason globulars are cool. The trick to getting the age for a cluster is that stars age at different rates. More massive stars burn through their nuclear fuel faster, so they run out before their smaller, more miserly brethren. When that happens the core of the star contracts and heats up, and the outer layers respond by inflating hugely, like a hot air balloon. The heat from the interior gets spread out through the much Getting the age of the cluster is possible because globulars have a very helpful characteristic: The stars are all the same distance away. That means if a star is brighter than another in the cluster, it really is more luminous. That makes comparing the stars directly to each other easier. At first it was assumed that all globulars are very old—as old as the Milky Way itself, 12 billion years or so—and that all the stars in each were born at the same time. But it gets a bit more complicated. Some, it turns out, clearly have stars that are old, mixed in with ones that are younger. The thinking is that these clusters are more massive, could draw in more gas over time, and then could have a second bout of star formation after the initial one. Photo by ESA/Hubble&NASA page 9 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 larger surface area, so weirdly the star gets much brighter but also much cooler. We call it a red giant (or a red supergiant if the star is particular massive). That’s the key. If you measure the stars’ colors, the ones that have run through their fuel and turned (or are currently turning) into red giants become very obvious. Theoretical models are pretty good at showing just how old the stars are that are right at that point in their lives, so that in turn must be the age of the cluster. Detail in the cluster (taken from the right side of the image above). Note how many faint stars can be seen ... and far more distant background galaxies can be seen right through the cluster! Photo by ESA/Hubble&NASA IC 4499 has always been a problem here. It has an intermediate mass between the lower-mass globulars that have a single population of stars and those heavier ones with two stellar populations. Knowing its age would be very helpful to nail down the difference between the two. Different studies have come up with different ages for it, with pretty large uncertainties, too. mediate cases, too, if we’re ever to have a fully filled-in picture of what’s really going on in the Universe. IC 4499 is another piece of that puzzle for which we’ve managed to find its place. The good news is that the Hubble observations easily cover the stars that are starting to turn in IC 4499, and the telescope’s ability to accurately resolve all the stars really nails down the age: IC 4499 is 12.0 ± 0.75 billion years. It’s old. This helps. Astronomers like to study extremes, since that tells us what physics is doing at the edge of what it can do. But we also need to figure out interpage 10 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 AstroShorts The University of California High-Performance AstroComputing Center (UC-HIPACC), based at the University of California, Santa Cruz, is a consortium of nine University of California campuses and three Department of Energy laboratories (Lawrence Berkeley Laboratory, Lawrence Livermore Laboratory, and Los Alamos National Laboratory). UC-HiPACC fosters collaborations among researchers at the various sites by offering travel and other grants, co-sponsoring conferences, and drawing attention to the world-class resources for computational astronomy within the University of California system. More information appears at http://hipacc.ucsc.edu . Separated at Birth: Finding our Sun’s Long-Lost Siblings? Stars are born in groups or clusters when a cold giant molecular cloud collapses under its own gravitational force. If many stars form all at once—that is, if star formation efficiency is high—they will stay together as a gravitationally bound open cluster (like the Pleiades) or a globular cluster (like M13 in Hercules). For more than a decade, it has been known that any two stars that are members of the same gravitationally bound star cluster always show the same pattern of chemical abundances. Stars are made mostly of hydrogen and helium, but they also contain traces of other elements: carbon, oxygen, iron, and even more exotic substances. By carefully measuring the wavelengths (colors) of light coming from a star, astronomers can determine how abundant each trace element is. “The pattern of abundances is like a DNA fingerprint, where all the members of a family share a com- Two 11-second movies at http://hipacc.ucsc.edu/PressRelease/sibling-stars_vid eos.html shows face-on and head-on views of a computational simulation of a collision of two converging streams of interstellar gas, leading to collapse and formation of a star cluster at the center. The simulation reveals that the gas streams are thoroughly homogenized well before stars begin forming. Credit: Mark Krumholz/ University of California, Santa Cruz page 11 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! mon set of genes,” said Mark Krumholz, associate professor at University of California, Santa Cruz. The pattern of abundances, set at birth, is consistent regardless of an individual star’s spectral type. But most stellar families don’t stay together: stars don’t form fast enough for them to remain gravitationally bound, and so groups of stars drift apart, eventually even ending up on opposite sides of a galaxy. That is likely what happened with our Sun. Thus, astronomers have long wondered whether it might be possible to tell if two stars now on opposite sides of the galaxy were born billions of years ago from the same cloud. In fact, they wondered, might it be possible to find our own Sun’s long-lost siblings? Why such family resemblance? Just one big problem: “Although we see that member stars of a long-lived star cluster today are chemically identical, we had no good reason to think that this would also be true of stars that were born together but then dispersed immediately,” explained Krumholz. After all, in a cloud where stars formed rapidly over a light-year apart, might the cloud not have had enough time to homogenize thoroughly, and form stars at the same time but not uniform in chemical composition? “We didn’t really know why stars are chemically homogeneous,” he said. “Without a solid understanding of the physical mechanism that produces uniformity, everything was at best a speculation.” ! ! ! ! October 2014 So Krumholz and his graduate student Yi Feng ran a fluid dynamics simulation on UCSC’s Hyades supercomputer. They simulated two streams of interstellar gas converging to form a cloud that, over a few million years, collapses under its own gravity to make a cluster of stars. In the simulation, they added red tracer dye to one stream and blue tracer dye to the other. Fast, early mixing “We found that, as the streams came together, they became extremely turbulent, very effectively mixing the red and blue tracer dyes,” Krumholz recounted. By the time the cloud started to collapse and form stars, everything was purple—and the resulting stars were purple as well. “This was a surprise,” Krumholz exclaimed. “I thought we’d get some blue stars and some red stars, instead of getting all purple stars. I didn’t expect the turbulence to be as violent as it was, and so I didn’t expect the mixing to be so rapid or efficient.” In other runs of the simulation, Krumholz and Feng observed that even clouds that do not turn much of their gas into stars—as the Sun’s parent cloud probably didn’t—still produce stars with nearly-identical abundances. Their findings have given the “chemical tagging” method a boost. “We’ve provided the missing physical explanation of how and why chemical mixing works, and shown convincingly that the chemical mixing process is very general and rapid even in an environment which did not yield a star cluster, like the one in which the Sun must have formed,” page 12 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! said Krumholz. “This is good news for prospects for finding the Sun’s long-lost siblings.” –Trudy E. Bell, M.A. Further reading: The paper “Early turbulent mixing as the origin of chemical homogeneity in open star clusters” is published in the August 31 online issue of Nature. A UC-HiPACC press release is at http://hipacc.ucsc.edu/PressRelease/sibling -stars.html and a UCSC press release is at http://news.ucsc.edu/2014/08/star-formati on.html. page 13 of 17 ! ! ! October 2014 page 14 of 17 Moon at perigee (closest to Earth) at 10h UT (362,476 km; angular size 33.0'). Full Moon at 10:50 UT. Total Eclipse of the Moon begins at 9:15 UT and ends at 12:34 UT. Mid-eclipse at 10:56 UT. Partial phases begin at 8:16 UT and end at 13:34 UT. The Moon will appear red-orange in color during totality (the Earth’s shadow). Visible from North America, Asia, Australia and much of the Pacific. 6 8 8 IC • Star Charts & Astro Posters • Telescopes & Binoculars All sales support the production and free distribution of The Evening Sky Map. • Star Atlases & Planispheres • Books for Sky Watchers PT I ND OR ke dey TH e sta ES r KY s. MA PT OF na NG w Hamal US I fe UL AB US S GRU PISC A U S T R II S NUS 3 RI 729 UA SU S Enif 7009 DELPHINUS CAPRICORNUS M2 M15 M2 7 AQ Alt SA A GIT L UI air TA R M1 1 IUS 2 NA S RO LI CO TRA S AU M1 6 5 T Te a h e po t M2 M2 M1 7 S EN ) P A R UD SE CA ( M2 1 M2 0 M ar s Symbols Galaxy Double Star W S Variable Star M6 ir e (d T Diffuse Nebula ud S I M7 o A Cl N r O a Planetary Nebula St IZ OR us -H gn Open Star Cluster Cy TO e N O Th Globular Star Cluster RI Z HO M8 Alnair MAY FREELY DISTRIBUTE PRINTED HANDOUTS. FULL DETAILS AT http://Skymaps.com/terms.html Star Magnitudes M F RO SKY us, T le . he D ia ng GH T r I SOUTH T -1 0 1 2 3 4 N HT S r ol p h i n , is a umme TAR T IRE r th e S s m all a t t r a c t i PATT E EN ve constellation nea E RN I Copyright © 2000–2014 Kym Thalassoudis. All Rights Reserved. WS TH O H N THE S S P A KY. INSTRUCTIONS: THE SKY M * TERMS OF USE: FREE FOR NON-COMMERCIAL EDUCATIONAL USE. ASTRONOMY EDUCATION GROUPS p hin RIG Del aut AQ A le SAVE ON RECOMMENDED PRODUCTS • http://Skymaps.com/store BY SC t EG 7 SKY MAP DRAWN FOR A LATITUDE OF 40° NORTH AND IS SUITABLE FOR LATITUDES UP TO 15° NORTH OR SOUTH OF THIS (Add 1 Hour For Daylight Saving) ! More sky events and links at http://Skymaps.com/skycalendar/ All times in Universal Time (UT). (USA Eastern Summer Time = UT – 4 hours.) IN ns E 3 31 First Quarter Moon at 2:48 UT. EG 25 28 Moon near Mars (56° from Sun, evening sky) at 12h UT. Mag. +0.9. a hd Dip S M33 ai PISCES nt le Fom alh rc P M5 M92 SKY MAP SHOWS HOW THE NIGHT SKY LOOKS EARLY OCT 8 PM LATE OCT 7 PM ! 25 Moon near Saturn (21° from Sun, evening sky) at 16h UT. Mag. +0.6. 25 Venus at superior conjunction with the Sun at 7h UT. Passes into the evening sky (not visible). S 23 Partial Eclipse of the Sun at 21:46 UT. Visible from Canada and the United States. Begins at 19:37, ends at 23:52 UT. Ci G re a of P t S q u a r ega sus e M13 OCTOBER 2014 ! 23 New Moon at 21:55 UT. Start of lunation 1136. 21 Orionid meteor shower peaks. Arises from the debris field of Comet Halley. Active from October 2 to November 7. Produces very fast (66 km/sec), generally faint meteors (20 per hour). Radiant located near Orion’s club asterism. Favorable viewing conditions this year but rates are expected to be low. 18 Moon at apogee (farthest from Earth) at 6h UT (distance 404,897 km; angular size 29.5'). 18 Moon near Jupiter (66° from Sun, morning sky) at 1h UT. Mag. –2.0. 17 Moon near Beehive Cluster (76° from Sun, morning sky) at 2h UT. 16 Mercury at inferior conjunction with the Sun at 21h UT. Not visible. Passes into the morning sky. 15 Last Quarter Moon at 19:12 UT. 12 Moon near Aldebaran (morning sky) at 10h UT. 11 Moon near the Pleiades (morning sky) at 15h UT. First Quarter Moon at 19:32 UT. 1 CORONA BOREALIS Get Sky Calendar on Twitter http://twitter.com/skymaps W HERCULES NORTHERN HEMISPHERE S Sky Calendar – October 2014 W K M ES CI N TI CANA E V a Gemm FREE* EACH MONTH FOR YOU TO EXPLORE, LEARN & ENJOY THE NIGHT SKY .S W CO c OÖ f t B l SERPENS a AP y a b (CAPUT) th OB P wi EA o v e n AL ) R M3 io i TI S ON s a l a t LES E t el CE b rig n s N. C ht RT rus co O A ctu p r I a A N rt i ng ORIZ D o ind AT ft H h E g w TH E e S M A lon i N l IS k D y is a T W M5 IM C LE ay on, E b CIR S. T a nd D rag ER H t h E a WEST , The tm O UT CE a N y Dr a c o T b TH E e ER O v isi ble f A ND F T HE rom a small city. I T H) MA P I D ( ZE N S THE PA RT OF THE SKY DIRECTLY OVERHEA The Evening Sky Map S. Albir eo AP n mi Eta R 9 39 Cr RA LY PT 33 I ECL 61 66 ARIE ang ki S ! Nu n Alg ol 5 S ANDROMEDA 466 le ub er Do lust C M31 ri r T IC A me OP EI 3 P US IO Sum CH S LI YM 9 EU DA ero SS ! HI U ! M2 M3 PH AR EU CA Deneb CE OP RS CYGNUS NCP Polaris PE TE AR a ST Veg H ! M12 O RT AC NO DR E URSA MINOR co It .B a. CE ed FA m Ple ro YOU CE d w i a de h NT An AT s CETUS ER o k i nd TH (J U ll ed sa N th e ST asu CTIO g e AS E p et P R I n i ri f y YO D Mira E UA ing t ar s TH RE m on of s AS DOI st e r e up SAME NG M e du mad E NOW m EAST s H s i a r T . ) SO e a st e P IS THE The Great Square of Pegasus is a larg E MA C OM P OF TH ASS DI OTTOM RECTION TH AT APPEARS ALONG THE B kh TH EL IT S ee S” M ND Gr RI CA al LA Thu ban Th ic PO M & izar Alc or OU O M5 1 Di e B C M9 lla pp ig N or C 4 pe M82 er W E Ca ar N o il ai M81 GA rl y th J RI my AR E CT pr o m e AU P S th AR i n e t s Y MA n E en t L h SK O re s e C a A NX d r e p THE Y T . L ED UR us S RN A BE rs e MA TU T Pe J WE O R ”) . E io n N R TH ll a t T HE st e “NO Z c on ENI LE T he T MP H Use A EXA N t NORTH h D e OR T B i H g E E (F D ip p e r (o S t ar . HOR IR C L r Plough) to find Polaris, the North I Z ON ON C . CO M HORIZ PASS DI RECTIONS ARE INDICATED ALONG THE “T ! M10 ASSNE Vol. 20, No. 10! October 2014 Brightest star in Aquila. Name means "the flying eagle". Dist=16.7 ly. The 6th brightest star. Appears yellowish in color. Spectroscopic binary. Dist=42 ly. Orange, giant K star. Name means "bear watcher". Dist=36.7 ly. Cepheid prototype. Mag varies between 3.5 & 4.4 over 5.366 days. Mag 6 companion. Brightest star in Cygnus. One of the greatest known supergiants. Dist=1,400±200 ly. Semi-regular variable. Magnitude varies between 3.1 & 3.9 over 90 days. Mag 5.4 companion. The 5th brightest star in the sky. A blue-white star. Dist=25.0 ly. Famous eclipsing binary star. Magnitude varies between 2.1 & 3.4 over 2.867 days. Brightest star in Piscis Austrinus. In Arabic the "fish's mouth". Dist=25 ly. The Seven Sisters. Spectacular cluster. Many more stars visible in binoculars. Dist=380 ly. The North Pole Star. A telescope reveals an unrelated mag 8 companion star. Dist=433 ly. And Aqr Aql Cep Cyg Cyg Dra Her Her Lyr Lyr Oph Oph Oph Oph Peg Per Sgr Sgr Sgr UMa Vul The Andromeda Galaxy. Most distant object visible to naked eye. Dist=2.93 million ly. Resembles a fuzzy star in binoculars. Bright Cepheid variable. Mag varies between 3.6 & 4.5 over 7.166 days. Dist=1,200 ly. Herschel's Garnet Star. One of the reddest stars. Mag 3.4 to 5.1 over 730 days. Long period pulsating red giant. Magnitude varies between 3.3 & 14.2 over 407 days. May be visible to the naked eye under good conditions. Dist=900 ly. Wide pair of white stars. One of the finest binocular pairs in the sky. Dist=100 ly. Best globular in northern skies. Discovered by Halley in 1714. Dist=23,000 ly. Fainter and smaller than M13. Use a telescope to resolve its stars. Famous Double Double. Binoculars show a double star. High power reveals each a double. Semi-regular variable. Magnitude varies between 3.9 & 5.0 over 46.0 days. Close to the brighter M10. Dist=18,000 ly. 3 degrees from the fainter M12. Both may be glimpsed in binoculars. Dist=14,000 ly. Large, scattered open cluster. Visible with binoculars. Scattered open cluster. Visible with binoculars. Only globular known to contain a planetary nebula (Mag 14, d=1"). Dist=30,000 ly. Double Cluster in Perseus. NGC 869 & 884. Excellent in binoculars. Dist=7,300 ly. Lagoon Nebula. Bright nebula bisected by a dark lane. Dist=5,200 ly. Bright cluster located about 6 deg N of "teapot's" lid. Dist=1,900 ly. A spectacular globular star cluster. Telescope will show stars. Dist=10,000 ly. Good eyesight or binoculars reveals 2 stars. Not a binary. Mizar has a mag 4 companion. Coathanger asterism or "Brocchi's Cluster". Not a true star cluster. Dist=218 to 1,140 ly. page 15 of 17 ! ! The Evening Sky Map (ISSN 1839-7735) Copyright © 2000–2014 Kym Thalassoudis. All Rights Reserved. Attractive double star. Bright orange star with mag 5 blue companion. Sep=9.8". Saturn Nebula. Requires 8-inch telescope to see Saturn-like appendages. Helix Nebula. Spans nearly 1/4 deg. Requires dark sky. Dist=300 ly. Impressive looking double blue-white star. Visible in a small telescope. Sep=7.8". Whirlpool Galaxy. First recognised to have spiral structure. Dist=25 million ly. Yellow star mag 3.4 & orange star mag 7.5. Dist=19 ly. Orbit=480 years. Sep=12". Beautiful double star. Contrasting colours of orange and blue-green. Sep=34.4". Attractive double star. Mags 5.2 & 6.1 orange dwarfs. Dist=11.4 ly. Sep=28.4". Appear yellow & white. Mags 4.3 & 5.2. Dist=100 ly. Struve 2725 double in same field. Eclipsing binary. Mag varies between 3.3 & 4.3 over 12.940 days. Fainter mag 7.2 blue star. Ring Nebula. Magnificent object. Smoke-ring shape. Dist=4,100 ly. Elongated star cluster. Telescope required to show stars. Dist=2,100 ly. Trifid Nebula. A telescope shows 3 dust lanes trisecting nebula. Dist=5,200 ly. A fine and impressive cluster. Dist=4,200 ly. Omega Nebula. Contains the star cluster NGC 6618. Dist=4,900 ly. Wild Duck Cluster. Resembles a globular through binoculars. V-shaped. Dist=5,600 ly. Eagle Nebula. Requires a telescope of large aperture. Dist=8,150 ly. Fine face-on spiral galaxy. Requires a large aperture telescope. Dist=2.3 million ly. Beautiful spiral galaxy visible with binoculars. Easy to see in a telescope. Dumbbell Nebula. Large, twin-lobed shape. Most spectacular planetary. Dist=975 ly. ! And Aqr Aqr Ari CVn Cas Cyg Cyg Del Lyr Lyr Sgr Sgr Sgr Sgr Sct Ser Tri UMa Vul ! Andromedae 7009 7293 Arietis M51 Cassiopeiae Albireo 61 Cygni Delphini Lyrae M57 M23 M20 M21 M17 M11 M16 M33 M81 M27 ! Telescopic Objects M31 M2 Aquilae Cephei Cygni M39 Draconis M13 M92 Lyrae R Lyrae M12 M10 IC 4665 6633 M15 Double Cluster M8 M25 M22 Mizar & Alcor Cr 399 ! Conjunction – An alignment of two celestial bodies such that they present the least angular separation as viewed from Earth. Constellation – A defined area of the sky containing a star pattern. Diffuse Nebula – A cloud of gas illuminated by nearby stars. Double Star – Two stars that appear close to each other in the sky; either linked by gravity so that they orbit each other (binary star) or lying at different distances from Earth (optical double). Apparent separation of stars is given in seconds of arc ("). Ecliptic – The path of the Sun’s center on the celestial sphere as seen from Earth. Elongation – The angular separation of two celestial bodies. For Mercury and Venus the greatest elongation occurs when they are at their most angular distance from the Sun as viewed from Earth. Galaxy – A mass of up to several billion stars held together by gravity. Globular Star Cluster – A ball-shaped group of several thousand old stars. Light Year (ly) – The distance a beam of light travels at 300,000 km/sec in one year. Magnitude – The brightness of a celestial object as it appears in the sky. Open Star Cluster – A group of tens or hundreds of relatively young stars. Opposition – When a celestial body is opposite the Sun in the sky. Planetary Nebula – The remnants of a shell of gas blown off by a star. Universal Time (UT) – A time system used by astronomers. Also known as Greenwich Mean Time. USA Eastern Standard Time (for example, New York) is 5 hours behind UT. Variable Star – A star that changes brightness over a period of time. Aql Aur Boo Cep Cyg Her Lyr Per PsA Tau UMi Easily Seen with Binoculars Altair Capella Arcturus Cephei Deneb Herculis Vega Algol Fomalhaut Pleiades Polaris Easily Seen with the Naked Eye ! Astronomical Glossary When observing the night sky, and in particular deep-sky objects such as star clusters, nebulae, and galaxies, it’s always best to observe from a dark location. Avoid direct light from street lights and other sources. If possible observe from a dark location away from the light pollution that surrounds many of today’s large cities. You will see more stars after your eyes adapt to the darkness—usually about 10 to 20 minutes after you go outside. Also, if you need to use a torch to view the sky map, cover the light bulb with red cellophane. This will preserve your dark vision. Finally, even though the Moon is one of the most stunning objects to view through a telescope, its light is so bright that it brightens the sky and makes many of the fainter objects very difficult to see. So try to observe the evening sky on moonless nights around either New Moon or Last Quarter. Tips for Observing the Night Sky Listed on this page are several of the brighter, more interesting celestial objects visible in the evening sky this month (refer to the monthly sky map). The objects are grouped into three categories. Those that can be easily seen with the naked eye (that is, without optical aid), those easily seen with binoculars, and those requiring a telescope to be appreciated. Note, all of the objects (except single stars) will appear more impressive when viewed through a telescope or very large binoculars. They are grouped in this way to highlight objects that can be seen using the optical equipment that may be available to the star gazer. About the Celestial Objects ! NORTHERN HEMISPHERE OCTOBER 2014 CELESTIAL OBJECTS ASSNE Vol. 20, No. 10! October 2014 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 MEMBERSHIP APPLICATION for the ASTRONOMICAL SOCIETY OF SOUTHERN NEW ENGLAND, INC. (ASSNE) The Astronomical Society of Southern New England, Inc. is an amateur astronomy club organized as a nonprofit corporation. ASSNE is composed of members who share a common interest in astronomy, science, and space. Since being founded in January, 1995, our mission has been to educate and inspire our members and the general public. We provide schools and other public venues with educational programs that may foster an awareness of astronomy and an appreciation of the night sky. Our annual Rehoboth Skies event, held each October, is a wonderful opportunity to share our knowledge and enthusiasm with the public. We also organize member star parties as well as tours to events and places having relevant astronomical presentations or programs. At our monthly meetings, members may participate in discussions and presentations given by members or by guest speakers, witness demonstrations, and observe the heavens with other members after meetings. ASSNE has a constitution and a set of bylaws, so that all members may become aware of the workings and direction of the club. This club was formed to promote the following goals: • Educate members and the general public in the various aspects of astronomy. • Allow members to come together and share their astronomical interests with others. • Encourage amateur participation in astronomical observing programs and research. • Organize, administer, and fund astronomy educational programs within the community. Our motto: To Educate and Inspire ____________________________________________________________ Membership (be it family or individual) is $20/year. Membership fees shall be pro-rated for new members by quarter, with no fee to be charged for the quarter in which the member/ family joins. (For example, a family joining in April would pay $15 instead of $20. And an individual joining in November would pay $5.) Your dues also entitle you to club discounts on subscriptions to Sky & Telescope Magazine, reduced membership dues for the Astronomical League, and access to the assets of ASSNE, which include books, videos, and free “loaner” telescopes. Be sure to get your S&T discount coupon from George at the next meeting. Our monthly newsletter and other information about us can be found on the Internet at http://www.assne.org. To save costs, the preferred method of communicating with members (apart from our meetings) is through the web using the club bulletin board at http://assne.org/board , or by e-mail (please no broadcast emails or BCC’s). Interested members and nonmembers who do not have Internet access may elect to receive a paper version of our newsletter, which will be prepared and mailed for the cost of doing so. page 16 of 17 ASSNE Vol. 20, No. 10! ! ! ! ! ! ! ! ! October 2014 APPLICATION FOR ASSNE MEMBERSHIP Please complete member info: Date: _____________ Name(s): _______________________________________________ Address: ______________________________________________________ ____________________________________________________________ Telephone: (______) ________________ Email:___________________________ Please check membership type as appropriate: (includes emailed monthly newsletter) ___ Single $20.00/yr ___ Donor $30/yr ___ Family $20.00/yr ___ Supporting $50/yr Optional services: ___ Mail the newsletter to me (Additional $12/year for costs) ___ Add discounted Astronomical League membership ($7.50/yr) $_______ TOTAL AMOUNT PAID ASSNE meets on the 2nd Saturday of every month, but members observe together informally throughout the month whenever the sky is clear. Would you like to receive invitations to observe with those members who regularly issue invitations to observe at their homes? (Even if you don’t make it, you’ll be emailed a copy of the night’s observing log.) ___Yes ___No If paying by check, please make it payable to ASSNE, Inc. And if mailing, please mail to: ASSNE, Inc. c/o George Huftalen 231 Metacom Ave. Warren, RI 02885 Or pay dues by PayPal: Go to www.PayPal.com, and follow the instructions. The address to use for dues or other ASSNE payments is [email protected] page 17 of 17