2018 March

AEA Astronomy Club Newsletter  March 2018

Contents

AEA Astronomy Club News & Calendar p.1
Video(s) & Picture(s) of the Month p. 2
Astronomy News p. 8
General Calendar p. 12

    Colloquia, lectures, mtgs. p. 12
    Observing p. 14

Useful Links p. 16
About the Club p. 17

Club News & Calendar.

Club Calendar

Club Meeting Schedule:

1 March	AEA Astronomy Club Meeting	Online Carnegie Lecture?	(A1/2906)
5 April	AEA Astronomy Club Meeting	Quarterly Pizza Party & Jay Landis Presentation	(A1/1735)

AEA Astronomy Club meetings are now on 1^st  Thursdays at 11:45 am.  For 2018:  Jan. 4 in A1/1029 A/B, Feb. 1 & March 1 in A1/2906 and for the rest of 2018 (April-Dec), the meeting room is A1/1735. 

We have reserved the night of Sat. Sept. 8 on the Mt. Wilson 100-inch telescope.  We do have a full manifest already – carry-overs from the 2017 night cancelled due to bad weather.  But if interested, we can still put you on the waiting list in case of cancellations, which typically do occur.

We have a speaker for June 7 from JPL – Rob Zellem, doing research on exoplanetary atmospheres.

“Exoplanets: Finding Life in the Galaxy”

Rob was born just outside the Philadelphia city limits but grew up in Hendersonville, TN. He went to Villanova University where he graduated with his Bachelor of Science in Astronomy and Astrophysics, minoring in Physics, Mathematics, and Classics, and getting an Honors Concentration. His love of travel and learning about other cultures brought him to University College London in England where he got his MSc in Space Science. He then moved out west to Tucson, AZ, where he received his PhD in Planetary Sciences from the Lunar and Planetary Laboratory at the University of Arizona. He is currently a scientist at NASA’s Jet Propulsion Laboratory supporting ground- and space-based instruments that will measure the atmospheres of extrasolar planets.

Club News:  

We need volunteers to help with: 

·         Populating our club Sharepoint site with material & links to the club’s Aerowiki & Aerolink materials

·         Arranging future club programs

·         Managing club equipment

Astronomy Video(s) & Picture(s) of the Month

(from Astronomy Picture of the Day, APOD: http://apod.nasa.gov/apod/archivepix.html

VIDEO:  Galaxy Formation in a Magnetic

Universe                                                                                                                                   https://apod.nasa.gov/apod/ap180219.html
Video Credit: IllustrisTNG Project; Visualization: Mark Vogelsberger (MIT) et al.
Music: Gymnopedie 3 (Composer: Erik Satie, Musician: Wahneta Meixsell)

Explanation: How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? To understand details better, astrophysicists upgraded the famous Illustris Simulation into IllustrisTNG -- now the most sophisticated computer model of how galaxies evolved in our universe. Specifically, this featured video tracks magnetic fields from the early universe (redshift 5) until today (redshift 0). Here blue represents relatively weak magnetic fields, while white depicts strong. These B fields are closely matched withgalaxies and galaxy clusters. As the simulation begins, a virtual camera circles the virtual IllustrisTNG universe showing a young region -- 30-million light years across -- to be quite filamentary. Gravity causes galaxies to form and merge as the universe expands and evolves. At the end, the simulated IllustrisTNG universe is a good statistical match to our present real universe, although some interesting differences arise -- for example a discrepancy involving the power in radio waves emitted by rapidly moving charged particles.

LL Ori and the Orion Nebula 
Image Credit: NASA, ESA, and The Hubble Heritage Team

Explanation: Stars can make waves in the Orion Nebula's sea of gas and dust. This esthetic close-up of cosmic clouds and stellar winds features LL Orionis, interacting with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged Sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed. The small, arcing, graceful structure just above and left of center is LL Ori's cosmic bow shock, measuring about half a light-year across. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the upper left corner of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. This beautiful painting-like photograph is part of a large mosaic view of the complex stellar nursery in Orion, filled with a myriad of fluid shapes associated withstar formation.

Enceladus in Silhouette 
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: One of our Solar System's most tantalizing worlds, Enceladus is backlit by the Sun in this Cassini spacecraft image from November 1, 2009. The dramatic illumination reveals the plumes that continuously spew into space from the south pole of Saturn's 500 kilometer diameter moon. Discovered by Cassini in 2005, the icy plumes are likely connected to an ocean beneath the ice shell of Enceladus. They supply material directly to Saturn's outer, tenuous E ring and make the surface of Enceladus as reflective as snow. Across the scene, Saturn's icy rings scatter sunlight toward Cassini's cameras. Beyond the rings, the night side of 80 kilometer diameter moon Pandora is faintly lit by Saturnlight.

Car Orbiting Earth 
Credit: SpaceX

Explanation: Last week, a car orbited the Earth. The car, created by humans and robots on the Earth, was launched by the SpaceX Company to demonstrate the ability of its Falcon Heavy Rocket to place spacecraft out in the Solar System. Purposely fashioned to be whimsical, theiconic car was thought a better demonstration object than concrete blocks. A mannequin clad in a spacesuit -- dubbed the Starman -- sits in the driver's seat. The featured image is a frame from a video taken by one of three cameras mounted on the car. These cameras, connected to the car's battery, are now out of power. The car, attached to a second stage booster, soon left Earth orbit and will orbit the Sun between Earth and the asteroid belt indefinitely -- perhaps until billions of years from now when our Sun expands into a Red Giant. If ever recovered,what's left of the car may become a unique window into technologies developed on Earth in the 20th and early 21st centuries.

Total Solar Lunar Eclipse 
Composite Image Credit & Copyright: Wang Letian, Zhang Jiajie

Explanation: This digitally processed and composited picture creatively compares two famous eclipses in one; the total lunar eclipse (left) of January 31, and the total solar eclipse of August 21, 2017. The Moon appears near mid-totality in both the back-to-back total eclipses. In the lunar eclipse, its surface remains faintly illuminated in Earth's dark reddened shadow. But in the solar eclipse the Moon is in silhouette against the Sun's bright disk, where the otherwise dark lunar surface is just visible due to earthshine. Also seen in the lunar-aligned image pair are faint stars in the night sky surrounding the eclipsed Moon. Stunning details of prominences and coronal streamers surround the eclipsed Sun. The total phase of the Great American Eclipse of August 21 lasted about 2 minutes or less for locations along the Moon's shadow path. From planet Earth's night side, totality for the Super Blue Blood Moon of January 31 lasted well over an hour.

Venus and the Triply Ultraviolet Sun 
Image Credit: NASA/SDO & the AIA, EVE, and HMI teams; Digital Composition: Peter L. Dove

Explanation: An unusual type of solar eclipse occurred in 2012. Usually it is the Earth's Moon that eclipses the Sun. That year, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun. Eventually the alignment became perfect and the phase of Venus dropped to zero. The dark spot of Venus crossed our parent star. The situation could technically be labeled a Venusian annular eclipse with an extraordinarily large ring of fire.Pictured here during the occultation, the Sun was imaged in three colors of ultraviolet light by the Earth-orbiting Solar Dynamics Observatory, with the dark region toward the right corresponding to a coronal hole. Hours later, as Venus continued in its orbit, a slight crescent phaseappeared again. The next Venusian transit across the Sun will occur in 2117.

Astronomy News:

(from https://www.sciencedaily.com ) 

Improved Hubble Yardstick Gives Fresh Evidence for New Physics in the Universe

·         Press Release - Source: NASA

·         Posted February 22, 2018 5:45 PM

·  

This illustration shows three steps astronomers used to measure the universe's expansion rate (Hubble constant) to an unprecedented accuracy, reducing the total uncertainty to 2.3 percent. The measurements streamline and strengthen the construction of the cosmic distance ladder, which is used to measure accurate distances to galaxies near to and far from Earth. The latest Hubble study extends the number of Cepheid variable stars analyzed to distances of up to 10 times farther across our galaxy than previous Hubble results.

Astronomers have used NASA's Hubble Space Telescope to make the most precise measurements of the expansion rate of the universe since it was first calculated nearly a century ago.

Intriguingly, the results are forcing astronomers to consider that they may be seeing evidence of something unexpected at work in the universe.

That's because the latest Hubble finding confirms a nagging discrepancy showing the universe to be expanding faster now than was expected from its trajectory seen shortly after the big bang. Researchers suggest that there may be new physics to explain the inconsistency.

"The community is really grappling with understanding the meaning of this discrepancy," said lead researcher and Nobel Laureate Adam Riess of the Space Telescope Science Institute (STScI) and Johns Hopkins University, both in Baltimore, Maryland.

Riess's team, which includes Stefano Casertano, also of STScI and Johns Hopkins, has been using Hubble over the past six years to refine the measurements of the distances to galaxies, using their stars as milepost markers. Those measurements are used to calculate how fast the universe expands with time, a value known as the Hubble constant. The team's new study extends the number of stars analyzed to distances up to 10 times farther into space than previous Hubble results.

But Riess's value reinforces the disparity with the expected value derived from observations of the early universe's expansion, 378,000 years after the big bang -- the violent event that created the universe roughly 13.8 billion years ago. Those measurements were made by the European Space Agency's Planck satellite, which maps the cosmic microwave background, a relic of the big bang. The difference between the two values is about 9 percent. The new Hubble measurements help reduce the chance that the discrepancy in the values is a coincidence to 1 in 5,000.

Planck's result predicted that the Hubble constant value should now be 67 kilometers per second per megaparsec (3.3 million light-years), and could be no higher than 69 kilometers per second per megaparsec. This means that for every 3.3 million light-years farther away a galaxy is from us, it is moving 67 kilometers per second faster. But Riess's team measured a value of 73 kilometers per second per megaparsec, indicating galaxies are moving at a faster rate than implied by observations of the early universe.

The Hubble data are so precise that astronomers cannot dismiss the gap between the two results as errors in any single measurement or method. "Both results have been tested multiple ways, so barring a series of unrelated mistakes," Riess explained, "it is increasingly likely that this is not a bug but a feature of the universe."

Explaining a Vexing Discrepancy

Riess outlined a few possible explanations for the mismatch, all related to the 95 percent of the universe that is shrouded in darkness. One possibility is that dark energy, already known to be accelerating the cosmos, may be shoving galaxies away from each other with even greater -- or growing -- strength. This means that the acceleration itself might not have a constant value in the universe but changes over time in the universe. Riess shared a Nobel Prize for the 1998 discovery of the accelerating universe.

Another idea is that the universe contains a new subatomic particle that travels close to the speed of light. Such speedy particles are collectively called "dark radiation" and include previously-known particles like neutrinos, which are created in nuclear reactions and radioactive decays. Unlike a normal neutrino, which interacts by a subatomic force, this new particle would be affected only by gravity and is dubbed a "sterile neutrino."

Yet another attractive possibility is that dark matter (an invisible form of matter not made up of protons, neutrons, and electrons) interacts more strongly with normal matter or radiation than previously assumed.

Any of these scenarios would change the contents of the early universe, leading to inconsistencies in theoretical models. These inconsistencies would result in an incorrect value for the Hubble constant, inferred from observations of the young cosmos. This value would then be at odds with the number derived from the Hubble observations.

Riess and his colleagues don't have any answers yet to this vexing problem, but his team will continue to work on fine-tuning the universe's expansion rate. So far, Riess's team, called the Supernova H0 for the Equation of State (SH0ES), has decreased the uncertainty to 2.3 percent. Before Hubble was launched in 1990, estimates of the Hubble constant varied by a factor of two. One of Hubble's key goals was to help astronomers reduce the value of this uncertainty to within an error of only 10 percent. Since 2005, the group has been on a quest to refine the accuracy of the Hubble constant to a precision that allows for a better understanding of the universe's behavior.

Building a Strong Distance Ladder

The team has been successful in refining the Hubble constant value by streamlining and strengthening the construction of the cosmic distance ladder, which the astronomers use to measure accurate distances to galaxies near to and far from Earth. The researchers have compared those distances with the expansion of space as measured by the stretching of light from receding galaxies. They then have used the apparent outward velocity of galaxies at each distance to calculate the Hubble constant.

But the Hubble constant's value is only as precise as the accuracy of the measurements. Astronomers cannot use a tape measure to gauge the distances between galaxies. Instead, they have selected special classes of stars and supernovae as cosmic yardsticks or milepost markers to precisely measure galactic distances.

Among the most reliable for shorter distances are Cepheid variables, pulsating stars that brighten and dim at rates that correspond to their intrinsic brightness. Their distances, therefore, can be inferred by comparing their intrinsic brightness with their apparent brightness as seen from Earth.

Astronomer Henrietta Leavitt was the first to recognize the utility of Cepheid variables to gauge distances in 1913. But the first step is to measure the distances to Cepheids independent of their brightness, using a basic tool of geometry called parallax. Parallax is the apparent shift of an object's position due to a change in an observer's point of view. This technique was invented by the ancient Greeks who used it to measure the distance from Earth to the Moon.

The latest Hubble result is based on measurements of the parallax of eight newly analyzed Cepheids in our Milky Way galaxy. These stars are about 10 times farther away than any studied previously, residing between 6,000 light-years and 12,000 light-years from Earth, making them more challenging to measure. They pulsate at longer intervals, just like the Cepheids observed by Hubble in distant galaxies containing another reliable yardstick, exploding stars called Type Ia supernovae. This type of supernova flares with uniform brightness and is brilliant enough to be seen from relatively farther away. Previous Hubble observations studied 10 faster-blinking Cepheids located 300 light-years to 1,600 light-years from Earth.

Scanning the Stars

To measure parallax with Hubble, the team had to gauge the apparent tiny wobble of the Cepheids due to Earth's motion around the Sun. These wobbles are the size of just 1/100 of a single pixel on the telescope's camera, which is roughly the apparent size of a grain of sand seen 100 miles away.

Therefore, to ensure the accuracy of the measurements, the astronomers developed a clever method that was not envisioned when Hubble was launched. The researchers invented a scanning technique in which the telescope measured a star's position a thousand times a minute every six months for four years.

The team calibrated the true brightness of the eight slowly pulsating stars and cross-correlated them with their more distant blinking cousins to tighten the inaccuracies in their distance ladder. The researchers then compared the brightness of the Cepheids and supernovae in those galaxies with better confidence, so they could more accurately measure the stars' true brightness, and therefore calculate distances to hundreds of supernovae in far-flung galaxies with more precision.

Another advantage to this study is that the team used the same instrument, Hubble's Wide Field Camera 3, to calibrate the luminosities of both the nearby Cepheids and those in other galaxies, eliminating the systematic errors that are almost unavoidably introduced by comparing those measurements from different telescopes.

"Ordinarily, if every six months you try to measure the change in position of one star relative to another at these distances, you are limited by your ability to figure out exactly where the star is," Casertano explained. Using the new technique, Hubble slowly slews across a stellar target, and captures the image as a streak of light. "This method allows for repeated opportunities to measure the extremely tiny displacements due to parallax," Riess added. "You're measuring the separation between two stars, not just in one place on the camera, but over and over thousands of times, reducing the errors in measurement."

The team's goal is to further reduce the uncertainty by using data from Hubble and the European Space Agency's Gaia space observatory, which will measure the positions and distances of stars with unprecedented precision. "This precision is what it will take to diagnose the cause of this discrepancy," Casertano said.

The team's results have been accepted for publication by The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

 General Calendar:

Colloquia, Lectures, Seminars, Meetings, Open Houses & Tours:

Colloquia:  Carnegie (Tues. 4pm), UCLA, Caltech (Wed. 4pm), IPAC (Wed. 12:15pm) & other Pasadena (daily 12-4pm):  http://obs.carnegiescience.edu/seminars/ 

Carnegie astronomy lectures – only 4 per year in the Spring www.obs.carnegiescience.edu.  Visit www.huntington.org for directions.  For more information about the Carnegie Observatories or this lecture series, please contact Reed Haynie.  . Click here for more information.

1 March			AEA Astronomy Club Meeting	Online Carnegie Lecture?	(A1/2906)
	2 March ?	Friday Night 7:30PM SBAS  Monthly General Meeting in the Planetarium at El Camino College (16007 Crenshaw Bl. In Torrance) Topic: ?  [their web site and newsletter are down]
	March 25
		UCLA Meteorite Gallery -- Location: UCLA Campus DR. AMY MAINZER NEAR-EARTH ASTEROIDS AND COMETS: CHARACTERIZING POPULATIONS WITH LARGE-AREA SURVEYS Location: Geology 3656 Time: 2:30PM Asteroid and comets have impacted Earth over millions of years; the key question is how often this occurs on shorter timescales. Recent work has focused on surveys of large regions of space to maximize their discovery rates and to characterize their physical properties. Dr. Amy Mainzer from the Jet Propulsion Laboratory is a UCLA Alumna who has been heavily involved in the use of data form the WISE infrared satellite to discover new asteroids and comets. She is also the host of a science TV show for children, "Ready Jet Go".

12 March

LAAS General Mtg. 7:30pm Griffith Observatory

 

The von Kármán Lecture Series: 2018

Planning Cassini’s Grand Finale: A Retrospective

March 22 & 23

Mission planning is a core strength of JPL engineering, along with deep space communications and navigation. This month’s talk, by Cassini mission planner Erick Sturm, will provide a look back at the various scenarios and contingency plans the Cassini team made as they steered the spacecraft into unexplored space during its 2017 Grand Finale. Sturm will discuss how the possible scenarios -- some of which could have been mission-ending -- compared to the mission as it was actually flown, along with some science highlights from the finale.

Speaker:
Erick Sturm - JPL Systems Engineer - Mission Planning lead for the Cassini Mission.

Location:
Thursday, March 22, 2018, 7pm
The von Kármán Auditorium at JPL
4800 Oak Grove Drive
Pasadena, CA
› Directions

Friday, March 23, 2018, 7pm
The Vosloh Forum at Pasadena City College
1570 East Colorado Blvd.
Pasadena, CA
› Directions

Webcast:
Click here to watch the event live on Ustream

5 April

AEA Astronomy Club Meeting

Quarterly Pizza Party & Jay Landis Presentation

(A1/1735)

Observing:

The following data are from the 2018 Observer’s Handbook, and Sky & Telescope’s 2018 Skygazer’s Almanac & monthly Sky at a Glance.

Current sun & moon rise/set/phase data for L.A.:  http://www.timeanddate.com/astronomy/usa/los-angeles

Sun, Moon & Planets for March:

  

Moon: March 2 Full, March 9 last quarter, March 17 new, March 24 1^st quarter                  

Planets: Venus visible at dusk.  Mars rises early morning, highest at dawn.  Mercury visible at dusk, best evening apparition of the year.  Saturn rises early morning, highest at dawn. Jupiter rises before midnight, visible until sunrise.

Other Events:

5 March Mercury 1.4 deg N. of Venus

11 March Daylight Savings Time begins

7,14,21,28 March

LAAS The Garvey Ranch Observatory is open to the public every Wednesday evening from 7:30 PM to 10 PM. Go into the dome to use the 8 Inch Refractor or observe through one of our telescopes on the lawn. Visit our workshop to learn how you can build your own telescope, grind your own mirror, or sign up for our free seasonal astronomy classes. Call 213-673-7355 for further information. Time: 7:30 PM - 10:00 PM Location: Garvey Ranch Obs. , 781 Orange Ave., Monterey Park, CA 91755

?	SBAS Saturday Night In Town Dark Sky Observing Session at Ridgecrest Middle School– 28915 North Bay Rd. RPV, Weather Permitting: Please contact Greg Benecke to confirm that the gate will be opened! http://www.sbastro.net/

17 March

LAAS Private dark sky  Star Party

?	SBAS out-of-town Dark Sky observing – contact Greg Benecke to coordinate a location. http://www.sbastro.net/.

20 March Vernal Equinox

24 March

LAAS Public  Star Party: Griffith Observatory Grounds 2-10pm

Internet Links:

Telescope, Binocular & Accessory Buying Guides

Sky & Telescope Magazine -- Choosing Your Equipment

Orion Telescopes & Binoculars -- Buying Guides

Telescopes.com -- Telescopes 101

General

Getting Started in Astronomy & Observing

The Astronomical League

 e! Science News Astronomy & Space

NASA Gallery

Astronomical Society of the Pacific (educational, amateur & professional)

Amateur Online Tools, Journals, Vendors, Societies, Databases

The Astronomy White Pages (U.S. & International Amateur Clubs & Societies)

American Astronomical Society (professional)

More...

Regional (Southern California, Washington, D.C. & Colorado)

Southern California & Beyond Amateur Astronomy Organizations, Observatories & Planetaria

Mt. Wilson Observatory description, history, visiting

Los Angeles Astronomical Society (LAAS)

South Bay Astronomical Society (SBAS)

Orange County Astronomers

The Local Group Astronomy Club (Santa Clarita)

Ventura County Astronomical Society

The Astronomical Society of Greenbelt

National Capital Astronomers

Northern Virginia Astronomy Club

Colorado Springs Astronomical Society

Denver Astronomical Society

About the Club

Club Websites:  Internal (Aerospace): https://aeropedia.aero.org/aeropedia/index.php/Astronomy_Club  It is updated to reflect this newsletter, in addition to a listing of past club mtg. presentations, astronomy news, photos & events from prior newsletters, club equipment, membership & constitution.  We have linked some presentation materials from past mtgs.  Our club newsletters are also being posted to an external blog, “An Astronomical View” http://astronomicalview.blogspot.com/. 

 
Membership.  For information, current dues & application, contact Alan Olson, or see the club website (or Aerolink folder) where a form is also available (go to the membership link/folder & look at the bottom).  Benefits will include use of club telescope(s) & library/software, membership in The Astronomical League, discounts on Sky & Telescope magazine and Observer’s Handbook, field trips, great programs, having a say in club activities, acquisitions & elections, etc.

Committee Suggestions & Volunteers.  Feel free to contact:  Mark Clayson, President & Program Committee Chairman (& acting club VP), TBD Activities Committee Chairman (& club Secretary), or Alan Olson, Resource Committee Chairman (over equipment & library, and club Treasurer).

Mark Clayson,
AEA Astronomy Club President