First Light Newsletter

October, 2014 Issue 123

AlachuaAstronomyClub.org

Astronomical League's pin for Constellation HunterProgram for Northern Skies.

Astronomical League's pin for the Double StarProgram.

North Central Florida's

Amateur Astronomy Club

Serving Alachua County since 1987

Member Member

Astronomical League

MemberNASA Night Sky Network

Twinkle, twinkle, variable starBy Dr. Ethan Siegel

Article from Space Place

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 growinto 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 theirbrightness’s vary by factors of thousands or more over the course of a single year! In fact, the first periodicor 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 ofstars burn through their fuel in a very consistent fashion, but in the case of pulsating variable stars theouter layers of stellar atmospheres vary. Initially heating up and expanding, they overshoot equilibrium,reach a maximum size, cool, then often forming neutral molecules that behave as light-blocking dust, withthe dust then falling back to the star, ionizing and starting the whole process over again. This temporarilyneutral dust absorbs the visible light from the star and re-emits it, but as infrared radiation, which isinvisible to our eyes. In the case of Mira (and many red giants), it's Titanium Monoxide (TiO) that causes itto dim so severely, from a maximum magnitude of +2 or +3 (clearly visible to the naked eye) to a minimumof +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 ispresently at magnitude +7 and headed towards its minimum, but will reach its maximum brightness againin 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! Lookfor it in your skies all winter long, and contribute your results to the American Association of Variable StarObservers (aavso.org) 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/

(click to enlarge)

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 thedistortions revealing the presence of a binary companion (lower left); public domain image of Orion, thePleiades and Mira (near maximum brightness) by Brocken Inaglory of Wikimedia Commons under CC-BY-SA-3.0 (lower right).

SchoolsMike Toomey

Outreach & Star PartiesIvo Rabell

Mike

Upcoming Events

Ivo

Rosemary Hill

For full details of events, please visit our website'sevents calendar.

October Public Meeting

Tuesday, Oct. 14, 2014, 7-9 p.m.Kika Silva Pla Planetarium

3000 NW 83rd StreetBuilding X-129

Gainesville, FL 32606

Join us for an exciting and interesting evening atthe Kika Silva Pla Planetarium (Santa Fe College)!Our speaker is Rich Russin, Alachua AstronomyClub. James Albury, planetarium director and co-host of the weekly TV show "Stargazers" is ourhost.

Welcome to new and renewing members duringthe past 30 days:

Robin CastellanosHoang HguyenWilliam RitzCheryl and John Troupe

Saturday, October 25, 20146:45 - 11 p.m.

4551 NE 110th Avenue, Bronson, FL

Rosemary Hill Observatory is a very dark site SWof Bronson, FL about 45 minutes from Gainesville,FL. Date of Star Party will be October 25th.Sunsets at 6:49 pm. Arrival should be between5:00 pm and 6:00 pm.

Starry Night at Florida Museum of NaturalHistory

Let's not forget major event of the year "StarryNight" at Florida Museum of Natural History onFriday, November, 14th. Museum is expectingaround 2000 visitors. Must set up telescopesbefore 5:00 pm. We need as many volunteers aspossible, with or without telescope.

Cheers,Ivo Rabell

PresidentAndy Howell

First Light Newsletter EditorLaura Wright

Alachua Astronomy Club membershave done a great job volunteeringfor Officer & Coordinator positionsduring 2015. Every officer andcoordinator is a leader. They makeit possible for the Club to do its workof promoting enjoyment and

awareness of astronomy by members and non-members alike.

Currently, the following positions seek nominationsfor the upcoming year 2015:

Vice PresidentTreasurer

WebmasterPrograms

If you have an interest in any of these openpositions, please let us know at volunteer@alachuaastronomyclub.org.

The OurVolts web site records that Club volunteers

The Alachua Astronomy Club is amember of the Astronomical Leagueand their logo is displayed near thetop of our newsletter. I went to theirwebsite to find out how they can helpus to be better observers.

"The Astronomical League provides many differentobserving programs which are designed to providea direction for your observations and to provide agoal." The programs are designed to be anindividual effort.

The League's "programs offer a certificate basedupon achieving certain observing goals andcompletion is recognized with a beautiful awardpin. You are required to observe a specific numberof objects from a list or of a specific type (meteors,comets, etc.) with a specific type of instrument(eyes, binoculars, telescope)."

"Each program is designed not only to show you avariety of objects in the sky and to learn somescience related to those objects, but to alsofamiliarize you with your telescope and how to use

have contributed 322 hours to the Club during thepast 10 months. This is an amazing number ofhours. It shows the dedication, spirit, and passionof our volunteers in contributing to the Club andcommunity!

Because Alachua Astronomy Club is a 501(c)(3)non-profit organization, it is important to keep trackof volunteer hours, if only to keep the IRS happy!The Club has exceptional members whogenerously share their time and passion forastronomy. Thank you!

In closing, get your orders for the 2015 Observers'Handbook to Howard Cohen. This handbook listskey celestial events during 2015 and contains awealth of other information. At the special price of$23.95 to AAC members (full retail $38.75), it's abargain!

Order Form2015 Observers' Handbook

Ordering Deadline: Oct 14

it, night-sky navigation (the ability to find theobjects in the vastness of space) and to learnsome observing techniques that will enhance yourviewing of the objects in the programs."

The Astronomical League has programs ofobservation experience ranging from beginner tointermediate to advanced. Similarly, the equipmentfor observing range from no special equipment orobserving with your eyes, to using binoculars tousing a telescope of differing sizes for advancedobserving.

The Constellation Hunter Program for NorthernSkies provides an "orientation to the sky for noviceastronomers. The program requires no specialequipment other than a planisphere and areference to the brighter objects names."

The Double Star Program introduces observers "to100 of the finest double and multiple stars in theheavens." The objects in this program can be"observed with a 3” refractor using between 75xand 150x." Many of the objects in this programcan be observed under less than optimumconditions.

Visit the Astronomical League’s website for all ofthe observing programs and challenge yourself tolearn more about your hobby and have fun doingit. Any questions please contact me and as thenew ALCOR I will do my best to assist. Thereference to any quoted materials in this article isfrom the League’s website www.astroleague.org.

Best regards,Laura

The Night Sky During October

From the One-Minute AstronomerUsed with permission.

October 2014 welcomes the Hunter Moon, the first full Moon of northern autumn. By chance, this month’sfull Moon passes into eclipse by the Earth for observers in most of North America, eastern Australia, andall of Hawaii and New Zealand. Later in the month, the Orionid meteor shower graces near-perfect sky asthe Earth passes through the debris-strewn path of Comet Halley. And an astonishing encounter: a tiny

comet grazes the planet Mars, an event which will makenews all over the world. Here’s what to see in the night skythis month . . .

1 Oct. First Quarter Moon, 19:33 UT

8 Oct. Full Moon, 10:51 UT. (“Hunter’s Moon”).

8 Oct. A total lunar eclipse is visible in much of NorthAmerica, all of Hawaii and New Zealand, and eastern partsof Australia. In eastern North America, the eclipse peaksnear dawn, but observers in western North America and thePacific see the eclipse in darkness. The partial lunar eclipsebegins at 09:15 UT, the total eclipse begins at 10:25 UT andends at 11:24 UT.

Universal Time. To convert from Universal Time (UT) to Eastern Daylight Time, subtract 4 hours. Thus,the partial lunar eclipse begins early on the morning of 8 Oct at 5:15 EDT, the total eclipse begins at 6:25EDT, and ends at 7:24 EDT.

Gainesville is positioned well to see the first half of the eclipse. Sunrise occurs at 7:27am EDT, andmoonset is 5 minutes later. If weather is clear, early risers will see the eclipsed moon hanging low in thewestern sky.

8 Oct. Look for the planet Uranus just 1º from the eclipsed full Moon (see below). The planet is a littlebrighter than 6th magnitude, so you can easily see it in binoculars.

Uranus is within 1 degree of the eclipsed Moon on October 8, 2014.

15 Oct. Last Quarter Moon, 19:12 UT

18 Oct. Look for Jupiter in the eastern sky before dawn. It’s close to the waning crescent Moon. Jupiter isslowly brightening and getting closer to Earth and will be a fine sight in a telescope in the coming months.

19 Oct. Comet C/2013 A1 Siding Spring passes within 132,000 km of Mars. That’s very, very close.Spacecraft on Mars and in orbit around the Red Planet will attempt to get images of the comet, so look fornews reports of the encounter. The comet is about 10th magnitude as seen from Earth. It will fit in thesame low-power field of view of Mars, which is setting in the southwestern sky at nightfall. At about 18:00UT on the 19th, the comet will appear to pass within 2′ (that’s 1/30th of a degree) from Mars. The planet istoo far away to reveal much detail in a telescope.

The path of Comet C/2013 A1 (Siding Spring) as it passes Mars on October 19, 2014.

21-22 Oct. The Orionid meteor shower peaks in very dark sky just before the new Moon. The Orionidsusually yield about 20-30 meteors per hour, though some years get as many as 50-70 per hour. Thesemeteors trace their paths back to a point in Orion near the border with Gemini. The Orionids occur whenEarth passes through the path of Comet Halley and encounters fine grains of dust ejected by thisvenerable and ancient cosmic snowball.

Approximate location of the radiant of the Orionid meteor shower at 2:00am EDT early onthe morning of Oct 21. Meteors may be seen for several days before and after the peak.

(Image Credit: Meteor Showers Online)

23 Oct. New Moon, 21:57 UT

25 Oct. Look for Saturn fading in the southwestern sky after sunset. Today it’s very close to a waxingcrescent Moon.

31 Oct. First Quarter Moon, 02:48 UT

Copyright © 2014 Alachua Astronomy Club, Inc. All rights reserved. Contact email: FirstLight@alachuaastronomyclub.org

Alachua Astronomy Club, Inc.P.O. Box 141591

Gainesville, FL 32614-1591

Unsubscribe