AEA Astronomy Club
Newsletter September
2021
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. 15
Useful
Links p. 17
About the Club p.
18
Club News &
Calendar.
Club Calendar
Club Meeting Schedule:
--
2 Sept Club Mtg -- Great Courses video via Teams
7 Oct Club Mtg -- Great Courses video via Teams
AEA Astronomy Club meetings are now on 1st Thursdays at 11:30 am. For 2020: Jan. & Feb. in A1/1735, March 5 in A1/2906 and for the rest of 2020 (April to Dec.) virtual meetings on Teams.
Club News:
The assembly of the Hubble Optics Dobs reportedly went well, but still needs collimation & encoder installation.
Club observing night on the Mt. Wilson 100” Oct. 30. The lucky 20 going be sure to make your payment.
Contact Jason Fields if interested in joining him for an observing
night with his 20” Dobs.
We need volunteers to help with:
·
Assembling
our new 16-inch Hubble Optics Dobs
·
Installing
our new software on our tablet & laptop
·
Populating
our club Sharepoint site with material & links to the club’s Aerowiki
& Aerolink materials – Kaly Rangarajan has volunteered to help with this
·
Arranging
future club programs
·
Managing
club equipment & library (Kelly Gov volunteered to help with the library)
Astronomy Video(s)
& Picture(s) of the Month
(generally from
Astronomy Picture of the Day, APOD: http://apod.nasa.gov/apod/archivepix.html)
VIDEO:
Solar System Ball Drop https://apod.nasa.gov/apod/ap210825.html
Video Credit & Copyright: James O'Donoghue (JAXA) & Rami Mandow (Space Australia); Text: James O'Donoghue
Explanation: Does a ball drop faster on Earth, Jupiter, or Uranus? The featured
animation shows a ball dropping from one kilometer high toward the surfaces
of famous
solar system bodies, assuming no air
resistance. The force of gravity depends
on the mass of the attracting
object, with higher masses pulling down with greater
forces. But gravitational
force also depends on distance from the center
of gravity, with shorter distances causing the ball to drop faster.
Combining both mass and distance, it might be surprising to see that Uranus pulls
the ball down slightly slower than Earth,
despite containing over 14 times more mass. This happens because Uranus has
a much lower density, which puts its cloud tops further away from its center
of mass. Although the falling ball always
speeds up, if you were on the ball you would not feel this acceleration because
you would be in free-fall.
Of the three planets mentioned, the
video demonstrates a ball drops even faster on Jupiter than
either Earth and Uranus.
AUDIO/IMAGE: The
Hubble Ultra Deep Field in Light and Sound
https://apod.nasa.gov/apod/ap210802.html
Image Credit: NASA, ESA, Hubble; Sonification: G. Salvesen (UCSB); Data: M.
Rafelski et al.
Explanation: Have you heard about the Hubble Ultra-Deep Field? Either way, you've likely not heard about it like this -- please run your cursor over the featured image and listen! The Hubble Ultra-Deep Field (HUDF) was created in 2003-2004 with the Hubble Space Telescope staring for a long time toward near-empty space so that distant, faint galaxies would become visible. One of the most famous images in astronomy, the HUDF is featured here in a vibrant way -- with sonified distances. Pointing to a galaxy will play a note that indicates its approximate redshift. Because redshifts shift light toward the red end of the spectrum of light, they are depicted here by a shift of tone toward the low end of the spectrum of sound. The further the galaxy, the greater its cosmological redshift (even if it appears blue), and the lower the tone that will be played. The average galaxy in the HUDF is about 10.6 billion light years away and sounds like an F#. What's the most distant galaxy you can find?
Rings Around the Ring Nebula
Image Credit: Hubble, Large Binocular Telescope, Subaru Telescope; Composition
& Copyright: Robert
Gendler
Explanation: The Ring
Nebula (M57), is more complicated than it appears through a small
telescope. The easily visible central ring is
about one light-year across,
but this
remarkably deep exposure - a collaborative effort combining
data from three different large telescopes - explores the
looping filaments of glowing gas extending much farther from the nebula's
central star. This composite
image includes red light emitted by hydrogen as well as visible
and infrared
light. The Ring Nebula is an elongated planetary
nebula, a type of nebula created when a Sun-like
star evolves to throw
off its outer atmosphere to become a white
dwarf star. The Ring Nebula is
about 2,500 light-years away toward the musical constellation Lyra.
Fire in Space
Image Credit: NASA
Explanation: What does fire look like in space? In the gravity on Earth,
heated air rises and expands, causing flames to be teardrop
shaped. In the microgravity of
the air-filled International
Space Station (ISS),
however, flames
are spheres. Fire is the rapid acquisition of oxygen, and space flames meet
new oxygen molecules
when they float by randomly from all directions -- creating the enveloping
sphere. In the featured
image taken in the ISS's
Combustion Integration Rack, a spherical
flame envelopes clusters of hot glowing soot.
Without oxygen, say in the vacuum of
empty space, a fire would
go out immediately. The many chemical reactions involved with fire are
complex, and testing
them in microgravity is helping
humanity not only to better understand fire -- but how to put
out fire,
too.
Jezero Crater: Raised Ridges in 3D
Image Credit: NASA, JPL-Caltech, Ingenuity
Explanation: Get out your red-blue glasses and hover
over the surface of Mars. Taken on July 24, the 3D color view is
from the Mars Ingenuity Helicopter's 10th flight
above the Red Planet. Two images from Ingenuity's color camera, both
captured at an altitude of 12 meters (40 feet), but a few meters apart to
provide a stereo perspective, were used to construct the color anaglyph.
Ingenuity's stereo images were made at the request of the Mars Perseverance rover
science team. The team is considering
a visit to these raised ridges on the floor of Jezero Crater
during Perseverance's first science campaign.
Tycho and Clavius
Image Credit & Copyright: Eduardo Schaberger
Poupeau
Explanation: South
is up in this detailed telescopic view across the Moon's rugged
southern highlands. Captured on July 20, the lunar landscape features the
Moon's young and old, the large craters Tycho and Clavius. About 100 million
years young, Tycho
is the sharp-walled 85 kilometer diameter crater near center,
its 2 kilometer tall central peak in bright sunlight and dark shadow.
Debris ejected during the impact that created Tycho still make it the stand
out lunar crater when the Moon is near full,
producing a highly visible radiating system of light streaks, bright rays that
extend across much of the lunar near side. In fact, some of the material
collected at the Apollo 17 landing site, about 2,000 kilometers away, likely
originated from
the Tycho impact. One of the oldest and largest craters on the
Moon's near side, 225 kilometer diameter Clavius
is due south (above) of Tycho. Clavius crater's own
ray system resulting from its original impact event would have faded long ago.
The old crater's worn walls and smooth floor are now overlayed by smaller
craters from impacts that occurred after Clavius was formed. Observations by
the Stratospheric Observatory for Infrared Astronomy (SOFIA) published in 2020
found water
at Clavius. Of course both young Tycho and old Clavius craters are
lunar locations in the science fiction epic 2001:
A Space Odyssey.
EHT Resolves Central Jet from Black Hole in Cen A
Image Credit: Radboud University; CSIRO/ATNF/I.Feain et al.,
R.Morganti et al., N.Junkes et al.; ESO/WFI; MPIfR/ESO/APEX/A. Weiss et al.;
NASA/CXC/CfA/R. Kraft et al.; TANAMI/C. Mueller et al.; EHT/M. Janssen et al.
Explanation: How do supermassive black holes create powerful jets? To
help find out, the Event
Horizon Telescope (EHT) imaged the center of the nearby active
galaxy Centaurus
A. The cascade of featured
inset images shows Cen A from it largest, taking up more sky than
many moons, to its now finest, taking up only as much sky as an golf
ball on the moon. The new image shows what may look like two jets --
but is actually two sides of a single jet.
This newly
discovered jet-edge brightening does not solve the jet-creation mystery,
but does imply that the particle outflow is confined by a strong pressure --
possibly involving a magnetic
field. The
EHT is a coordination of radio telescopes from around the
Earth -- from the Caltech
Submillimeter Observatory in Hawaii USA,
to ALMA in Chile,
to NOEMA in France,
and more.
The EHT will continue to observe massive, nearby black holes and
their energetic surroundings.
Astronomy
News:
From
ScienceNews.org
NASA
readies James Webb space telescope for December launch
NASA plans to launch the James Webb Space Telescope into orbit
Dec. 18, 2021, to serve as the premier deep space observatory for the next
decade.
The agency set the new target launch date in coordination with
Arianespace after Webb recently and successfully completed its rigorous testing
regimen – a major turning point for the mission. The new date also follows
Arianespace successfully launching an Ariane 5 rocket in late July and
scheduling a launch that will precede Webb. The July launch was the first for
an Ariane 5 since August 2020.
Webb, an international program led by NASA with its partners ESA
(European Space Agency) and the Canadian Space Agency, will launch on an Ariane
5 from Europe's Spaceport in French Guiana on the northeastern coast of South
America. ESA is providing the Ariane 5.
The highly complex space telescope is currently resting in its
final stow configuration at Northrop Grumman's facilities in Redondo Beach,
California.
"Webb is an exemplary mission that signifies the epitome of
perseverance," said Gregory L. Robinson, Webb's program director at NASA
Headquarters in Washington. "I am inspired by our dedicated team and our
global partnerships that have made this incredible endeavor possible. Together,
we've overcome technical obstacles along the way as well as challenges during
the coronavirus pandemic. I also am grateful for the steadfast support of
Congress. Now that we have an observatory and a rocket ready for launch, I am
looking forward to the big day and the amazing science to come."
The Webb team is preparing for shipment operations, during which
the observatory will undergo final closeout procedures and packing for its
journey to the launch site. The major elements of the Ariane 5 rocket that will
carry Webb into space have safely arrived in Kourou, French Guiana, from
Europe.
The Webb telescope's revolutionary technology will explore every
phase of cosmic history – from within our solar system to the most distant
observable galaxies in the early universe, and everything in between. Webb will
reveal new and unexpected discoveries, and help humankind understand the
origins of the universe and our place in it.
Explore further
Webb completes testing and prepares
for trip to Europe's Spaceport
More information: Mission
information: www.webb.nasa.gov
Provided by NASA's Goddard Space Flight Center
Gases
in Milky Way are not homogeneously mixed, contrary to previous models
In order to better understand the history and evolution of the
Milky Way, astronomers are studying the composition of the gases and metals
that make up an important part of our galaxy. Three main elements stand out:
the initial gas coming from outside our galaxy, the gas between the stars
inside our galaxy—enriched with chemical elements –, and the dust created by
the condensation of the metals present in this gas.
Until now, theoretical models assumed that these three elements
were homogeneously mixed throughout the Milky Way and reached a level of
chemical enrichment similar to the sun's atmosphere, called the solar
metallicity. Today, a team of astronomers from the University of Geneva (UNIGE)
demonstrates that these gases are not mixed as much as previously thought,
which has a strong impact on the current understanding of the evolution of galaxies.
As a result, simulations of the Milky Way's evolution will have to be modified.
These results can be read in the journal Nature.
Galaxies are made up of a collection of stars and
are formed by the condensation of the gas of the intergalactic medium composed
of mostly hydrogen and a bit of helium. This gas does not contain metals unlike
the gas in galaxies—in astronomy, all chemical elements heavier than helium are
collectively called metals, although they are atoms in gaseous form.
"Galaxies are fueled by 'virgin' gas that falls in from the
outside, which rejuvenates them and allows new stars to form," explains Annalisa
De Cia, a professor in the Department of Astronomy at the UNIGE Faculty of
Science and first author of the study. At the same time, stars burn the
hydrogen that constitutes them throughout their life and form other elements
through nucleosynthesis. When a star that has reached the end of its life
explodes, it expels the metals it has produced, such as iron, zinc, carbon and
silicon, feeding these elements into the gas of the galaxy. These atoms can
then condense into dust, especially in the colder, denser parts of the galaxy.
"Initially, when the Milky Way was formed, more than 10 billion years ago,
it had no metals. Then the stars gradually enriched the environment with the
metals they produced," continues the researcher. When the amount of metals
in this gas reaches the level that is present in the sun, astronomers speak of
solar metallicity.
A not so homogeneous environment
The environment that makes up the Milky Way thus brings together
the metals produced by the stars, the dust particles that have formed from
these metals, but also gases from outside the galaxy that regularly enter it.
"Until now, theoretical models considered that these three elements were
homogeneously mixed and reached the solar composition everywhere in our galaxy,
with a slight increase in metallicity in the center, where the stars are more
numerous," explains Patrick Petitjean, a researcher at the Institut
d'Astrophysique de Paris, Sorbonne University. "We wanted to observe this
in detail using an Ultraviolet spectrograph on the Hubble Space
Telescope."
Spectroscopy allows the light from stars to be separated in its
individual colors or frequencies, a bit like a with prism or in a rainbow. In
this decomposed light, astronomers are particularly interested in absorption
lines: "When we observe a star, the metals that make up the gas between
the star and ourselves absorb a very small part of the light in a
characteristic way, at a specific frequency, which allows us not only to
identify their presence, but also to say which metal it
is, and how abundant it is," he continues.
A new method developed to observe the total metallicity
For 25 hours, the team of scientists observed the atmosphere of
25 stars using Hubble and the Very Large Telescope (VLT) in Chile. The problem?
The dust cannot be counted with these spectrographs, even though it contains
metals. Annalisa De Cia's team has therefore developed a new observational
technique. "It involves taking into account the total composition of the
gas and dust by simultaneously observing several elements such as iron, zinc,
titanium, silicon and oxygen," explains the Geneva researcher. "Then
we can trace the quantity of metals present in the dust and add it to that
already quantified by the previous observations to get the total."
Thanks to this dual observation technique, the astronomers have
found that not only is the Milky Way's environment not homogeneous, but that
some of the areas studied reach only 10% of the solar metallicity. "This
discovery plays a key role in the design of theoretical models on the formation and
evolution of galaxies," says Jens-Kristian Krogager, researcher at the
UNIGE's Department of Astronomy. "From now on, we will have to refine the
simulations by increasing the resolution, so that we can include these changes
in metallicity at different locations in the Milky Way."
These results have a strong impact on our understanding of the
evolution of galaxies and of our own
in particular. Indeed, metals play a fundamental role in the formation of
stars, cosmic dust, molecules and planets. And we now know that new stars and
planets could be formed today from gases with very different compositions.
Explore further
Cosmic galaxy assembly and the
evolution of metals
More information: Large metallicity
variations in the Galactic interstellar medium, Nature (2021). DOI: 10.1038/s41586-021-03780-0 , www.nature.com/articles/s41586-021-03780-0
Journal information: Nature
Provided by University of Geneva
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 Zoom Digital Series
Zoom Webinar Platform
July Night Sky Network
Clubs & Events
https://nightsky.jpl.nasa.gov/clubs-and-events.cfm
2 Sept AEA Astronomy Club Mtg. Great Courses video by Teams
1Sept
16 The von Kármán Lecture Series: 2021
Credit: NASA/JPL-Caltech
Instrumental: Engineers Who Make Science Possible
September 16
Time: 7 p.m. PDT (10 p.m. EDT; 0300 UTC)
Pollution creates particulate matter (tiny floating particles) and
aerosols that can be harmful to our health. With missions like the Multi-Angle
Imager for Aerosols (MAIA), public health officials can start to map this
particulate matter around the world, understand its effect on diseases, and
know where the most risk is. In this month’s talk, we'll chat with the
instrument operations systems engineer for MAIA and discuss how vital positions
like hers are for mission success and for making sure important data gets back
to us on Earth.
Speaker(s):
Janelle Wellons, Instrument Operations Systems Engineer, NASA/JPL
Host:
Brian White, Public Services Office, NASA/JPL
Co-Host:
Jocelyn Argueta, Public Outreach Specialist, NASA/JPL
|
Sept 19 |
DR. MELANIE BARBONI; ARIZONA STATE
UNIVERSITY
DISCOVERING LOST LUNAR MAGMAS USING
APOLLO ZIRCONS
Location: https://ucla.zoom.us/meeting/register/tJEqduyupj0vGd3S0_52FsbHTbPjYr0sZQUj
An accessible record of the processes leading to the origin and early
evolution of the Earth-Moon system, and thus of the formation of the rocky
planets of the inner solar system, is best preserved in those precious rocks
brought back from the surface of the Moon half a century ago. Indeed, Lunar
magmatic rocks not only recorded critical information about planetary differentiation,
they also recorded the tempo of meteorite impacts in the early inner solar
system. Lunar zircons found within Apollo samples record over 500 Ma (from
4.4 to 3.9 Ga) of the Moon's magmatic history and are thought to have
crystallized during one of the two situations described above (primary
differentiation of the Moon or in later impact events). However, identifying
which zircon derives from the crystallization of the Lunar Magma Ocean, and
which crystallized in subsequent impact melts is not straight forward. This
is because most lunar rocks record a mixture of these primary and secondary
processes, preserving chemical signatures inherited from early magmatism and
potentially overprinted by secondary impact heating. In this talk, I will
present old and new geochemical tools applied to Lunar zircons that, used
together, have the potential to decipher the complex magmatic history of the
Moon and re-discover lunar magmas that got lost along the tumultuous history
of our shiny neighbor.
|
|||
|
7 Oct |
AEA Astronomy Club Meeting |
TBD -- Great Courses video |
(Teams) |
||
Observing:
The
following data are from the 2021 Observer’s Handbook, and Sky & Telescope’s
2021 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 September:
Moon: Sept 7 new, Sept 13 1st
quarter, Sept 20 Full, Sept 29 last quarter
Planets:
Venus
shines brightly in the west-southwest at dusk. Mars
is too close to the Sun to be viewed all month. Jupiter and Saturn rise
before dusk and transit in the late evening,
Mercury
is lost in the Sun’s glare all month.
Other
Events:
LAAS Event Calendar (incl.
various other virtual events):
https://www.laas.org/laas-bulletin/#calendar
2 Aug Saturn at
opposition
|
Cancelled |
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. Time: 7:30
PM - 10:00 PM Location: Garvey
Ranch Obs. , 781 Orange Ave., Monterey Park, CA 91755 |
|
2 Oct |
SBAS In-town
observing session – In Town Dark Sky Observing Session at Ridgecrest
Middle School– 28915 NortbBay Rd. RPV, Weather Permitting: Please contact Ken
Munson to confirm that the gate will be opened. http://www.sbastro.net/. Only if we get
permission to use the school grounds again and CDC guidelines are reduced |
|
4 Sept |
SBAS
out-of-town Dark Sky observing – contact Ken Munson to coordinate a location.
http://www.sbastro.net/. |
|
4 Sept |
LAAS Private dark
sky Star Party |
14 Sept Mercury greatest elongation E (27deg)
14 Sept Neptune at opposition
22 Sept Autumnal equinox
|
Cancelled |
LAAS Public
Star Party: Griffith Observatory Grounds 2-10pm See http://www.griffithobservatory.org/programs/publictelescopes.html#starparties for more information. |
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
e! Science News Astronomy & Space
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)
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)
The Local Group Astronomy Club
(Santa Clarita)
Ventura County Astronomical
Society
The
Astronomical Society of Greenbelt
Northern
Virginia Astronomy Club
Colorado
Springs 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 Kaly Rengarajan, 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: Jason Fields, President & Program Committee Chairman, Sam
Andrews, VP, Kelly Gov club Secretary (& librarian), or Kaly Rangarajan,
(Treasurer).
Mark Clayson,
AEA Astronomy Club Newsletter Editor
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