AEA Astronomy Club Newsletter October 2020
Contents
AEA Astronomy Club News & Calendar p.1
Video(s) & Picture(s) of the Month p. 2
Astronomy News p. 11
General Calendar p. 13
Colloquia, lectures, mtgs. p. 13
Observing p. 16
Useful
Links p. 17
About the Club p.
18
Club News &
Calendar.
Club Calendar
Club Meeting Schedule:
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AEA Astronomy Club Meeting |
TBD -- Great Courses video |
Teams
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5 Nov |
AEA Astronomy Club Meeting |
TBD -- Great Courses video |
(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:
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: GW
Orionis: A Star System with Tilted Rings https://apod.nasa.gov/apod/ap200929.html
Animation Illustration Credit: ESO, U. Exeter, S.
Kraus et
al., L.
Calçada
Explanation: Triple star system GW Orionis appears to demonstrate that
planets can form and orbit in multiple planes. In contrast, all the planets and
moons in our
Solar System orbit in nearly the same plane.
The picturesque
system has three prominent stars, a warped disk, and inner
tilted rings of gas and grit. The featured animation characterizes
the GW
Ori system from observations with the European Southern Observatory's VLT and ALMA telescopes
in Chile.
The first
part of the illustrative video shows a grand vista of the
entire system from a distant orbit, while the second sequence takes
you inside the tilted rings
to resolve the three central co-orbiting stars.
Computer simulations
indicate that multiple stars in systems like GW Ori could warp and break-up disks
into unaligned, exoplanet-forming
rings.
VIDEO: Salt Water
Remnants on Ceres https://apod.nasa.gov/apod/ap200901.html
Video Credit: Dawn Mission, NASA, JPL-Caltech, UCLA, MPS/DLR/IDA
Explanation: Does Ceres have underground pockets of water? Ceres,
the largest asteroid in the asteroid
belt, was thought to be composed of rock and ice. At the same time, Ceres was known to
have unusual bright spots on its surface. These bright spots were clearly
imaged during Dawn's exciting approach in
2015. Analyses of Dawn images and spectra indicated that the bright spots arise
from the residue of highly-reflective salt water that used to exist on Ceres'
surface but evaporated. Recent
analysis indicates that some of this water may have originated from
deep inside the dwarf planet, indicating Ceres to be a kindred spirit with
several Solar System
moons, also thought to harbor deep water pockets. The featured video shows
in false-color pink the bright evaporated brine named Cerealia Facula in Occator Crater. In
2018, the mission-successful
but fuel-depleted Dawn spacecraft
was placed in a distant parking orbit, keeping it away from the Ceres'
surface for at least 20 years to avoid interfering with any life
that might there exist.
VIDEO: A Thousand
Meteors https://apod.nasa.gov/apod/ap200912.html
Video Credit & Copyright: Greg Priestley
Explanation: Over a thousand meteors flash through the night in
this intriguing timelapse
video. Starting in April 2019 the individual video frames were
selected from 372 relatively clear nights of imaging from an automated
wide-field observatory in rural New South Wales Australia. Arranged by local
sidereal time, a timekeeping system that uses the positions of stars
to measure Earth's rotation, the frames follow the full annual progression of
constellations through the wide field of view seen from 33 degrees south
latitude. They capture a diverse
array of meteors including sporadic
meteors, bright fireballs, and shower meteors (plus a lightning
sprite), during the period. All frames were processed consistently
and so show real variations in the local sky conditions.
Filaments of the Cygnus Loop
Image Credit: ESA/Hubble & NASA, W.
Blair; Acknowledgement: Leo Shatz
Explanation: What lies at the edge of an expanding supernova? Subtle and
delicate in appearance, these ribbons of shocked interstellar gas are part of a
blast wave at the expanding edge of a violent stellar explosion that
would have been easily visible to humans during the late
stone age, about 20,000 years ago. The featured image was
recorded by the Hubble
Space Telescope and is a closeup of the outer edge of a
supernova remnant known as the Cygnus Loop or Veil Nebula.
The filamentary shock front is moving
toward the top of the frame at about 170 kilometers per second,
while glowing in light emitted by atoms of excited hydrogen gas.
The distances to stars thought to be interacting with the Cygnus Loop have
recently been found by the Gaia mission to be about 2400 light years distant.
The whole Cygnus
Loop spans six full Moons across
the sky, corresponding to about 130 light years,
and parts can be seen with a small telescope toward the constellation of
the Swan (Cygnus).
Enceladus in Infrared
Image Credit: VIMS
Team, SSI, U. Arizona, U. Nantes, CNRS, ESA, NASA
Explanation: One of our Solar System's most tantalizing worlds,
icy Saturnian moon Enceladus appears in these detailed hemisphere views from
the Cassini spacecraft. In false color, the
five panels present 13 years of infrared image data from
Cassini's Visual and Infrared Mapping Spectrometer and Imaging Science
Subsystem. Fresh
ice is colored red, and the most dramatic features look like long
gashes in the 500
kilometer diameter moon's south polar region. They correspond
to the location of tiger
stripes, surface fractures that likely connect to an ocean beneath the
Enceladus ice shell. The fractures are the source of the moon's icy plumes that
continuously spew
into space. The plumes were discovered by by Cassini in 2005. Now,
reddish hues in the northern half of the leading hemisphere view also indicate
a recent resurfacing of other regions of the geologically active moon, a world
that may hold conditions suitable for life.
ISS Transits Mars
Image Credit & Copyright: Tom Glenn
Explanation: Yes, but have you ever seen the space station do this? If
you know when and where to
look, watching the bright International
Space Station (ISS) drift across your night sky is a fascinating sight --
but not very unusual. Images of the ISS crossing in front of the
half-degree Moon or Sun do
exist, but are somewhat rare as they take planning, timing, and patience to
acquire. Catching the ISS crossing in front of minuscule Mars,
though, is on another level. Using online
software, the featured photographer learned that the unusual transit
would be visible only momentarily along a very narrow stretch of nearby land
spanning just 90 meters. Within this stretch, the equivalent ground
velocity of the passing ISS image would be a quick 7.4
kilometers per second. However, with a standard camera, a small
telescope, an exact location to set up his equipment, an exact direction to
point the telescope, and sub-millisecond timing -- he created a video from which the
featured 0.00035 second exposure was extracted. In the resulting image
capture, details on both Mars and the ISS are visible
simultaneously. The featured
image was acquired last Monday at 05:15:47 local time from just
northeast of San
Diego, California, USA.
Although typically much smaller, angularly, than the ISS, Mars is
approaching its maximum angular size in the next
few weeks, because the blue
planet (Earth) is set to pass
its closest to the red
planet (Mars) in their respective orbits around the Sun.
Orion in Depth
Illustration Credit & Copyright: Ronald
Davison
Explanation: Orion
is a familiar constellation. The apparent positions of its
stars in two dimensions create a well-known pattern on
the bowl of planet Earth's night sky. Orion may not look quite
so familiar in this 3D view though. The
illustration reconstructs the relative positions of Orion's
bright stars, including data from the Hipparcus catalog of parallax distances.
The most distant star shown is Alnilam. The middle one in the projected line of
three that make up Orion's belt when viewed from planet Earth, Alnilam is
nearly 2,000 light-years away, almost 3 times as far as fellow belt stars Alnitak
and Mintaka. Though Rigel and Betelgeuse apparently shine brighter in planet
Earth's sky, that makes more distant Alnilam intrinsically (in absolute
magnitude) the brightest of the familiar stars in Orion. In the Hipparcus
catalog, errors in measured parallaxes for Orion's stars can translate in to
distance errors of a 100 light-years or
so.
Biomarker Phosphine Discovered in the Atmosphere of Venus
Image Credit: ISAS, JAXA, Akatsuki; Processing: Meli
thev
Explanation: Could there be life floating in the atmosphere of Venus?
Although Earth's
planetary neighbor has a surface considered too extreme for any
known lifeform, Venus' upper atmosphere may be sufficiently mild for tiny
airborne microbes.
This usually disfavored prospect took an unexpected
upturn yesterday with the announcement of the discovery
of Venusian phosphine. The chemical phosphine (PH3)
is a considered a biomarker because
it seems so hard to create from routine chemical processes thought to occur on
or around a rocky
world such as Venus --
but it is known to be created by microbial life on Earth.
The featured
image of Venus and its thick clouds was taken in two bands
of ultraviolet
light by the Venus-orbing Akatsuki,
a Japanese
robotic satellite that has been orbiting the cloud-shrouded world since 2015.
The phosphine finding,
if confirmed, may set off renewed interest in searching for other indications
of life floating high in the atmosphere of our
Solar System's second planet out from the Sun.
GW190521: Unexpected Black Holes Collide
Illustration Credit: Raúl Rubio (Virgo Valencia Group, The Virgo Collaboration)
Explanation: How do black holes like this form? The two black holes that
spiraled together to produce the gravitational wave event GW190521 were not only the most
massive black holes ever seen by LIGO and VIRGO so far, their masses -- 66 and
85 solar masses -- were unprecedented and unexpected. Lower mass black holes,
below about 65 solar masses are known to form in supernova explosions.
Conversely, higher mass black holes, above about 135 solar masses, are thought
to be created by very
massive stars imploding after they use up their weight-bearing
nuclear-fusion-producing elements.
How such intermediate
mass black holes came to exist is yet unknown, although one hypothesis
holds that they result from consecutive collisions of stars and black holes in
dense star clusters. Featured
is an illustration of the black holes just before collision, annotated
with arrows indicating their spin axes. In the illustration, the spiral waves
indicate the production of gravitational
radiation, while the surrounding stars highlight the possibility that the merger occurred in
a star cluster.
Seen last year but emanating from an epoch when the universe was only about
half its present age (z ~
0.8), black hole merger GW190521 is
the farthest yet detected, to within measurement errors.
A Falcon 9 Moon
Image Credit & Copyright: Katie Darby
Explanation: Illuminating planet Earth's night, full moons can have many
names. This year the last full moon of northern hemisphere summer was on
September 2, known to some as the Full Corn
Moon. A few days earlier on August 30 this almost full moon rose just
before sunset though, shining through cloudy skies over Cape Canaveral Air
Force Station on Florida's Space Coast. A well-timed
snapshot caught
the glare of rocket engines firing below the lunar disk, a Falcon 9
rocket's first stage successfully returning to Cape
Canaveral's landing zone 1. About 9 minutes earlier, the same SpaceX Falcon 9
rocket had
launched the SAOCOM 1B satellite toward polar orbit. The fourth launch
for this reusable Falcon 9 first stage, it was the first launch to a polar orbit from
Cape Canaveral since 1969.
A Halo for Andromeda
Digital Illustration Credit: NASA, ESA, J. DePasquale and E. Wheatley (STScI) and Z. Levay
Explanation: M31, the Andromeda Galaxy, is the closest large spiral
galaxy to our Milky Way. Some 2.5 million light-years distant it shines in
Earth's night sky as a small, faint, elongated cloud just visible to the
unaided eye. Invisible to the eye though, its enormous halo of hot ionized gas
is represented in purplish hues for this
digital illustration of our neighboring galaxy above rocky terrain. Mapped
by Hubble Space Telescope observations of the absorption of ultraviolet light
against distant quasars, the extent and make-up of Andromeda's gaseous halo has
been recently
determined by the AMIGA project. A reservoir of material for future star
formation, Andromeda's halo of diffuse plasma was measured to extend
around 1.3 million light-years or more from the galaxy. That's about half way
to the Milky Way, likely putting it in contact with the diffuse gaseous halo of
our own galaxy.
Astronomy
News:
A spherical star cluster has surprisingly few heavy elements
https://www.sciencenews.org/article/globular-star-cluster-surprising-few-heavy-elements
Called RBC EXT8,
the cluster challenges some theories of how galaxies form and evolve
HUBBLE/ESA AND NASA, G. PIOTTO
A
strange, newly measured clump of stars orbiting the nearby Andromeda galaxy has
the lowest level of heavy chemical elements ever seen in one of these
mysterious star clusters. Named RBC EXT8, this globular cluster is also surprisingly
massive, challenging theories for how such clusters and some
galaxies form, astronomers report online October 15 in Science.
“It’s
a very unusual object,” says astrophysicist Oleg Gnedin of the University of
Michigan in Ann Arbor, who was not involved in the new discovery.
Globular
clusters are crowded, spherical collections of stars that orbit a galaxy’s
center, though most, including RBC EXT8, live in the galactic outskirts. The
clusters are typically billions of years old, so their stars tend to be
chemically pristine, meaning they formed before the universe had time to create
much of any of the elements heavier than hydrogen or helium, which astronomers
lump together as “metals.”
Previous
observations of these clusters in the Milky Way and other galaxies had
suggested that there’s a limit to how low a globular cluster’s metal content
can be. The most metal-poor clusters were about 300 times less rich in heavy
elements like iron than the sun, but no less.
But
spectra of RBC EXT8, some 2.5 million light-years away, show that the cluster’s
metal content is about 800 times less than the sun’s. The globular cluster that
held the previous record for lowest “metallicity” has three times that amount.
“It
was completely unexpected that we would find a globular cluster that is so
metal poor,” says astronomer Søren Larsen of Radboud University in Nijmegen,
the Netherlands.
What’s more, given its metal-poor status,
this cluster is surprisingly massive, weighing about 1.14 million times the
mass of the sun. (A mid-weight globular cluster is about 100,000 solar masses,
but some clusters reach 3 million solar masses. RBC EXT8 is heavy, but not the
heaviest.)
That
mass makes the cluster even harder to explain because across the cosmos, the
more massive a galaxy or cluster is, the more heavy elements it normally has.
There
are several potential explanations for that trend, but one is simply that more
massive galaxies or globular clusters have more stars. A star fuses heavy
elements in its core and sprinkles them around its host cluster or galaxy as it
ages. Sufficiently massive stars can explode in a supernova,
spreading those metals to become part of the next generation of stars (SN:
8/9/19).
So more stars means more opportunity for metals to accumulate locally.
More
massive objects also have the advantage of gravity, which lets them better hold
on to the metals that they do have and remain a cohesive group for billions of
years. Less massive globular clusters dissolve into their host galaxies over
time.
Those
trends together could have explained the apparent “metallicity floor” for
globular clusters — all of the less massive, more metal-poor clusters have
broken apart over the eons.
RBC
EXT8 turns that conventional wisdom on its head. “It’s too big to have as low
metallicity as it has,” Gnedin says. “That’s the conundrum.”
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/
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1 Oct |
AEA Astronomy Club Meeting |
TBD -- Great Courses video |
(Teams) |
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Cancelled
for now |
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Friday Night 7:30PM SBAS Monthly General Meeting in the Planetarium at El Camino College (16007 Crenshaw
Bl. In Torrance) |
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Oct. 15 The von Kármán Lecture Series: 2020
Galaxy of Horrors: Terrifying Real Planets
Time: 7 p.m. PDT (10 p.m. EDT;
0200 UTC)
There are many deadly and mysterious phenomena out there in the Milky Way. This
month’s show will profile some of the real — and terrifying — marvels of
astrophysics and exoplanets exposing some of the dangers lurking in the
darkness of space...
Host:
Brian White
Co-Host:
Thalia Rivera, Public Outreach Specialist, JPL
Speaker(s):
Dr. Tiffany Kataria, Exoplanet Scientist, JPL
Dr. Daniel Stern, Astrophysicist, JPL
Dr. Jacqueline McCleary, Astrophysicist, JPL
Webcast:
›
Click here to watch the event live on YouTube
›
Click here to watch the event live on Ustream
Past shows are archived on
YouTube.
›
Click here for the YouTube playlist of past shows
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19 Oct |
LAAS General Mtg. 7:30pm Griffith Observatory
(private) |
|
Oct 18 2020 |
DR. DONALD BROWNLEE
THE
GOLDEN AGE OF SAMPLE RETURN MISSIONS FROM SPACE: WHAT COMET SAMPLES HAVE TOLD
US ABOUT THE ORIGIN OF THE SOLAR SYSTEM
Location:
https://ucla.zoom.us/meeting/register/tJEqduyupj0vGd3S0_52FsbHTbPjYr0sZQUj In the past 15 years, space
missions have returned samples of the Sun, a comet and an asteroid for
detailed study by state-of-the-art methods in laboratories around the world.
Samples from two additional asteroids are being returned by current missions
and return missions from the Moon and Mars are planned. Starting 30 years
after the last Apollo lunar mission, some have called these new missions the
Golden Age of post-Apollo sample return missions. In this talk, I will
describe the Stardust mission and how the ancient rocky materials it returned
from an active comet have given us important new insight into the formation
of icy-bodies near the edge of the solar system. Just as Moore’s Law led to
vast improvements in our computers, analogous advances in microanalytical
methods have led to unprecedented capabilities for studying extraterrestrial
materials. In the case of comet samples, the analyses have found abundant
rocky materials that formed at incandescent temperatures, probably in the
inner solar system. Such materials were profoundly unexpected components in a
body whose ices formed at cryogenic temperature. Their presence in comets is
evidence of large scale transport of rocky materials from the hottest regions
of the early solar system to its coldest parts.  |
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AEA Astronomy Club Meeting |
TBD -- Great Courses video |
Teams
|
Observing:
The
following data are from the 2020 Observer’s Handbook, and Sky & Telescope’s
2020 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 October:
Moon: Oct 1 Full, Octt 10 last quarter, Oct 16 new, Oct 23 1st
quarter
Planets:
Venus
is a brilliant morning star all month. Mars
rises around sunset, at opposition on the 13th. Jupiter visible in the early evening, Saturn culminates at dusk and sits 5deg to 7deg east of Jupiter, Mercury
is hidden in the Sun’s glare all month.
Other
Events:
1 Oct Mercury greatest
elongation E (26deg)
3 Oct Mars 0.7deg N
of Moon
|
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 |
6 Oct Mars at closest
approach
13 Oct Mars at Opposition
|
? |
SBAS In-town
observing session – In Town Dark Sky Observing Session at
Ridgecrest Middle School– 28915 NortbBay Rd. RPV, Weather Permitting: Please
contact Ken Rossi or 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 |
|
17 Oct |
LAAS Private dark
sky Star Party |
22 Oct Jupiter 2deg N of Moon
|
? |
SBAS
out-of-town Dark Sky observing – contact Greg Benecke to coordinate a
location. http://www.sbastro.net/. |
|
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 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, Walt
Sturrock, VP, Kelly Gov club Secretary (& librarian), or Alan Olson,
Resource Committee Chairman (over equipment, and club Treasurer).
Mark Clayson,
AEA Astronomy Club President
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