April First Light Newsletter
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April First Light Newsletter April 2014 Issue 118 AlachuaAstronomyClub.org North Central Florida's Amateur Astronomy Club April 15, 2014 Total Lunar Eclipse Serving Alachua County since 1987 Member Member M. L. McGaughran obtained this nice image of the Astronomical NASA April 15 total lunar eclipse using a Canon EOS 7D League Night Sky Network and 400 mm lens. The star "h Vir" V mag = 5.21 is visible in the upper left of the photograph. (click photograph to enlarge) Other AAC members who photographed the eclipse include Howard Cohen, Howard Eskildsen, Andy Howell, and Don Loftus. The Power of the Sun's Engines April Space Place article by Dr. Ethan Siegel Here on Earth, the sun provides us with the vast majority of our energy, striking the top of the atmosphere with up to 1,000 Watts of power per square meter, albeit highly dependent on the sunlight's angle-of-incidence. But remember that the sun is a whopping 150 million kilometers away, and sends an equal amount of radiation in all directions; the Earth-facing direction is nothing special. Even considering sunspots, solar flares, and long-and-short term variations in solar irradiance, the sun's energy output is always constant to about one-part-in-1,000. All told, our parent star consistently outputs an estimated 4 × 1026 Watts of power; one second of the sun's emissions could power all the world's energy needs for over 700,000 years. That's a literally astronomical amount of energy, and it comes about thanks to the hugeness of the sun. With a radius of 700,000 kilometers, it would take 109 Earths, lined up from end-to-end, just to go across the diameter of the sun once. Unlike our Earth, however, the sun is made up of around 70% hydrogen by mass, and it's the individual protons - or the nuclei of hydrogen atoms - that fuse together, eventually becoming helium-4 and releasing a tremendous amount of energy. All told, for every four protons that wind up becoming helium-4, a tiny bit of mass - just 0.7% of the original amount - gets converted into energy by E=mc2, and that's where the sun's power originates. You'd be correct in thinking that fusing ~4 × 1038 protons-per-second gives off a tremendous amount of energy, but remember that nuclear fusion occurs in a huge region of the sun: about the innermost quarter (in radius) is where 99% of it is actively taking place. So there might be 4 × 1026 Watts of power put out, but that's spread out over 2.2 × 1025 cubic meters, meaning the sun's energy output per-unit-volume is just 18 W / m3. Compare this to the average human being, whose basal metabolic rate is equivalent to around 100 Watts, yet takes up just 0.06 cubic meters of space. In other words, you emit 100 times as much energy-per-unit-volume as the sun! It's only because the sun is so large and massive that its power is so great. It's this slow process, releasing huge amounts of energy per reaction over an incredibly large volume, that has powered life on our world throughout its entire history. It may not appear so impressive if you look at just a tiny region, but - at least for our sun - that huge size really adds up! Composite of 25 sun images, showing solar activity over a 365 day period. NASA Solar Dynamics Observatory / Atmospheric Imaging Assembly S. Wiessinger; post-processing by E. Siegel Check out these “10 Need-to-Know Things About the Sun”: http://solarsystem.nasa.gov/ planets/profile.cfm? Kids can learn more about an intriguing solar mystery at NASA's Space Place: http://spaceplace.nasa.gov/sun-corona Schools Outreach & Star Parties Mike Toomey Ivo Rabell On April 3rd, the school The March 29th outreach cadre entertained Rosemary Hill over 150 visitors to Williston Observatory star party Elementary School, Levy was cancelled due to County. Chuck Broward, Lisa clouds but keep looking Eager, Alexandrea Matthews, out for future star parties at this Patrick McSween, Ivo Rabell and I site. Until then, here is a history of attended on behalf of the club. Before RHO: sundown, we enjoyed a beautiful crescent moon. Eventually, Jupiter appeared, and Rosemary Hill Observatory is an finally, after patiently waiting out a few astronomical observatory located clouds, we presented many other near Bronson, Florida, 24 miles showcase objects such as the Great Orion southwest of Gainesville, Florida. Nebula. The observatory is owned and operated by the University Of Florida. Established in 1967, the observatory sits on 80 acres which were donated by Mrs. Marie Hergert. The observatory was named after the rosemary plant which has grown around the two domes. Rosemary plant is a woody perennial herb with fragrant evergreen needle-like leaves. The name derives from Latin meaning "dew of the sea". The observatory's two domes are 75 feet above sea level. It also has dormitories for observing runs. The largest dome has a 30 inch Cassegrain reflector telescope built by Tinsley Laboratories and commissioned in 1968. The telescope can be used as an F/4 Newtonian focus or F/16 Cassegrain Paula, Christopher, Frank, and Kylie hold some free focus. The instrument is equipped astronomy reading materials handed out by with a photometric CCD camera, Alexandrea Matthews. filter wheels, and standard Credit: Lisa Statham Posteraro photometric filter. It is occasionally used for instruction, but is primarily used for monitoring active galaxies, performing photometry of transiting exoplanets, and other research purposes. Hopefully next time we will have clear skies! KidsFest - Upcoming Event Fun 4 Gators and A Child's Academy are hosting "KidFest" behind Corda Roy's at the corner of 8th Ave & Newberry Road on Saturday, May 3rd. Visitors will include toddlers, middle Gunnar looks into Mike Toomey's 12½” Newtonian schoolers, and parents. Bring your own kids or grandkids to event. Admission is free! reflecting telescope. Patiently waiting their turn are Jose, Ken, and Taylour. AAC members will bring safe solar telescopes Credit: Lisa Statham Posteraro and show the Sun's prominences, sunspots, and possibly a solar flare. We close out our school year at an Alachua County school on May 8th. (click image to enlarge) Please log onto the website and register for the event location. We have one summer program on the calendar so far – Millhopper Library “Fun Friday”. We will be setting up solar viewing – or we will have an indoor alternative if the weather does not cooperate. The program will run on Friday, June 13 from 2 p.m. until about 3 p.m. We anticipate 50 – 100 guests of all ages. Andy Howell and I would like to remind members that attend any of our outreach events to please log their volunteer time on the OurVolts.com web site. This is not a contest among members. Rather, we really would like to demonstrate how much the club contributes to the community. School outreach volunteers will get a reminder after each event to log in. Once you're registered, it takes only For full details of events, please visit seconds to record your time. our Event Calendar. April & May Meteors Member Profile of the Month Andy Howell Jared Feldman The Lyrids are active I am a second year from April 16 through 25, Aerospace and peaking on April 21/22. Mechanical The radiant is actually in Engineering student at eastern Hercules, but the University of relatively close to the Florida, hence why I bright star Vega. The shower is moved to Gainesville in late 2012. I associated with Comet Thatcher have a strong interest in all things (C/1861 G1). The best time to see related to space and the universe the Lyrids is anytime after midnight, beyond our own planet. This interest with optimal viewing during the hour led me to my current area of study or so before dawn. Lyra will be and work experience with a Launch directly overhead at this time, Services company. I spent last although a meteor could appear in summer working for United Launch any part of the sky. Alliance where I worked on the Subcontract Management and Bright Lyrid (mag -1) seen early Tuesday Procurement Team. I will be morning, April 22 above Gainesville returning this summer to ULA’s factory in Decatur, Alabama working hands-on assembling their rockets. The main reason I joined the club was to learn more about a telescope given to me by my grandfather while I was cleaning his attic a few months ago. He was Woody Allen’s chauffeur for over 15 years and he acquired the telescope from Woody. It is a Questar and seems to be in very good shape. I am looking forward to learning more about the telescope In early May, the eta Aquariids and astronomy in general while also swing into view. This shower is getting to know the club's members active from April 19 - May 26, with better! peak activity predicted on May 5/6. This meteor shower is associated with particles from Comet Halley that are on the outbound portions of their orbits around the sun. The radiant rises at 1:30am local time, and best viewing is the hour before dawn when 10-30 meteors per hour might be visible under good conditions. Meteor observing requires no equipment except your own eyes! It's a great way to get back to basics and enjoy the night sky. Let me know what you see at meteors@alachuaastronomyclub.