The Galactic Times Newsletter #17 - February 1 - 14, 2022
This Just In: Sailing to Alpha Cen., Pleiades Lost and Found, The Weakest Atmospheres, Earth's Trojans!, Dying Stars Create Babies, Hot Jupiter's Air; Be a Valentine GOAT, Sky Planning Calendar.
Light Sail spacecraft may be heading towards our nearest stellar neighbor, Alpha Centauri, a.k.a. Rigel Kentaurus, as visible near dawn down in the Caribbean. (SkyViewcafe.com)
In This Issue:
Cover Photo — Target: Alpha Centauri
This Just In — Stories in the Current Night Sky 1. Sailing, Sailing (Flying to Alpha Centauri- Cover Story) 2. Pleiades Lost and Found
The Weakest Atmospheres Go Trojans! Yes, Dying Stars Do Cause Stars to Be Born The Layers in the Atmosphere of a Hot Exoplanet
Sky Planning Calendar — * Moon-Gazing - Moon by Jupiter, and That’s About It * Observing—Plan-et — Mercury Makes a Southern Hemisphere Splash; Mars Wimps Out by Venus. * Border Crossings — Valentine’s Day is Coming, Be a Goat, er, GOAT…
The Classroom Astronomer Inbox Magazine Issue 18 Highlights
Welcome to The Galactic Times Inbox Magazine, #17!
Click herehttps://www.thegalactictimes.com for our Home Page, with all past issue Tables of Contents and stories indexed by topic. You can also hear and find useful materials for education from our former podcast, now on this website (plus links to other Hermograph products and periodicals).
Head here - https://thegalactictimes.substack.com — for our (Free) Subscription Page and subscribe, or read in the Archive, or just enter the box at the end of the issue.
If you are enjoying this twice-monthly newsletter, please support it by 1) using the link at the end to spread copies to your colleagues and friends and urge them to subscribe (why should you do all the emailing, right? We’re glad to do it!) and 2) if you are an educator, subscribe to the Classroom Astronomer Inbox Magazine, too!
Colonize Mars? Pshaw! How parochial. How Elon Musk.
Some folks dream further. A lot further. Like four light years further. Like in our life times.
NASA is preparing to launch not one, not two, but three solar sail space flights in the next three years. Following up on the crowd-funded LightSail 2, February could see the launch of NEA Scout, a mission to a Near Earth Asteroid called 2020ge. A second “light sail” will be launched later in this year to further test materials.
But the big project is set for 2025. The Starshot project is actually a fleet of tiny solar sail probes, which will gain added thrust not just from solar photons and solar winds but a very large laser until it is cruising at 0.20c. The probes will be headed to Proxima Centauri b, a recently discovered Earth-sized planet in the star system nearest to us. At this speed, it will arrive in about 30 years.
A minor issue….neither the probes, sails nor lasers are built and proven to work yet…. Though funded by some very big and deep-pocketed folks (not Musk, by the way), details on what would be the most powerful and expensive laser, and where it would be placed (back side of the moon, perhaps? Earth orbit? ), are not specified. Nor how we will get the information on Proxima b back to us. Hopefully no Proximates will consider a fleet of sails an act of war…..
[Proxima and Alpha Centauri are visible around 4:30 AM due South, but only if you further south than the latitude of, say, Key West, Florida…..
2. Pleiades Lost and Found
The beautiful star cluster well visible in February skies, the Pleiades, has featured in mythology for thousands of years. One legend even says that there was once a seventh bright star—most people today see easily just six without optical aid. But in reality, there are over a thousand stars in the cluster. As pointed out below, the Moon will go by the Pleiades, a young star cluster of only about 125 million years old. But as star clusters age, they dissipate and disperse, as our Sun once did from its now-lost brethren. Are there lost Pleiads around the sky? Yes, and astronomers Jeremy Heyl, Ilaria Caiazzo and Harvey Richer have found nearly 300 escapees through their motions as recorded by the powerful Gaia satellite. One of them is a distant naked eye star, 41 Tauri, and several are white dwarf stars, which is important because they have to be among the oldest of the cluster’s stars. It sets a limit to how far escapees could have ‘flown the coop’ during the cluster’s lifetime. [Astrophysical Journal, in press]
The Pleiades (ESA)
* The Weakest Atmospheres
Atmospheres in the Solar System are not for the weak, at least the weakest in gravity, and at least, not in having atmospheres of large quantities. Pluto has a very thin one, we know. What we have just learned is that that atmosphere has haze particles in it, and they have two sizes. Pluto’s atmosphere is comparable with those of Titan and Triton in terms of composition, with N2 being the dominant component, percent-level abundances of CH4, and smaller amounts of CO. The haze in the section below Pluto’s tropopause is a larger-size population “of ~1 μm two-dimensional aggregates with ~20 nm monomers while the smaller-size population consists of ~80 nm spheres”.
On the other end of the Solar System, little Mercury has an atmosphere made primarily of solar wind particles it has trapped in its small magnetosphere. Data from the Messenger Mercury mission indicates that there are ultra-low frequency shocks ahead of Mercury in its meager boundary between its magnetic field and the solar wind. This is of some value to exoplanetary scientists as it may be a way of detecting magnetic fields around exoplanets. [Both stories in Nature Communications, Fan, Gao and Yung, January 11, and Romanelli & DiBraccio, 29 November 2021, respectively. ]
* Go Trojans!
No, not the Michigan State sports teams….
With all the hoopla about the James Webb Telescope heading out to the L2 position in the Earth orbital position, what about asteroids in the other Lx positions? Jupiter, of course, is well known for having numerous asteroids in the L4 and L5 spots. Like over 7000 numerous. Neptune is in a distant second place with… 23. <gulp> Mars, in third with 9. Planets Uranus, Earth and Venus in fourth place with one. But Earth breaks out from the pack and scores! It’s got a second Trojan! Asteroid 2020 XL5 (a number with sci-fi connotations for those of a certain age) is found to be a Trojan in the L4 zone. Despite numerous telescopic surveys and even looksee’s by two space missions passing by, only one other Trojan has been spotted and that one only about a decade ago. XL5 is actually bigger than the first one, 2010 TK7, and the authors of the NatureCommunications article [T. Santana-Ros and 16 others, February 1.] suggest the ~1 km asteroid would be a good target for a space mission. It will stick around L4 and wait for us for about 4000 years before departing….
* Yes, Dying Stars Do Cause Stars to Be Born
It has long been a mantra of stellar evolution that new stars are formed from the debris of long dead stars, that supernovae seed the interstellar medium (ISM) with ‘metals’ (elements heavier than helium) that ultimately collapse into new stars. There has long been evidence, some of which we showed in the last The Galactic Times that supernovae push out against the ISM and cause areas of new stars to be created (the story last time on the Local Bubble around the Sun caused by some ancient supernova). Now we see this happening in the strangest and most unexpected of places, a far-away dwarf galaxy called Henize 2-10.
This small piece of cosmic fluff would normally be something overlooked. Dwarf galaxies don’t have a lot of activity in them, including not much in the way of star formation. But the little guy hasn’t gotten the memo; it is engaged in some real starburst activity. At the center of it all is a black hole, a massive one but not as massive as the one in the center of the Milky Way, and its outflow is ramming hard into the dwarf galaxy’s ISM and setting up a great deal of star formation in the collision area.
Henize 2-10 is close—it has to be for us to see this much detail—only 30 million light years away, 15 times the distance to our neighbor, the nearby Andromeda Galaxy. Being so small, the normal high-speed outbound jets of gas are not found; instead the slower jets allow the colliding gases to hang together long enough to cool and form stars instead of being blasted into space.
[Personal note: Henize 2-10 is named for Dr. Karl Henize, a NASA scientist-astronaut, who flew on Spacelab/Space Shuttle 51-F, and was backup on Apollo and Skylab missions. He and I shared the same astronomer-mentor, spectroscopist Dr. William Bidelman, and both of us worked on similar projects, objective prism spectroscopy surveys and S-stars. We shared a great lunch together once at NASA Houston, a few years before his flight. Sadly, he died at Mt. Everest testing NASA equipment.]
* The Layers in the Atmosphere of a Hot Exoplanet
We’re getting closer and closer to being able to know how exoplanets are, as in their atmosphere compositions and meteorologies. Not quite yet for any exo-Earths but here’s a hot Jupiter for you. A European group analyzed the atmosphere of a hot-Jupiter, WASP-189b, a planet that is rotationally locked to its star, about two Jupiters in mass. As it transits in front of the star, spectroscopic analysis of the atmosphere of the planet indicates a bunch of metals, Fe, Cr, Mg, Mn, Ti, V, Fe+, Ti+ and TiO, as well as tentative detection of five others (Na, Ca, Sc+, Cr+ and Ni). What they also found is that the various metals, especially TiO, vary apparently because of winds distributing the metals around, and because the night side is cooler so metals condense out. But because the metals have different thermal characteristics, the metals can be found at different altitudes, meaning there is layering in the planet’s atmosphere. [Nature Astronomy, January 27, 2022, B. Prinoth et al.]
Sky Planning Calendar
Moon-Gazing
Moon passages by a star, planet or deep sky object are a good way to find a planet or other object if you’ve never located it before.
February 1 New Moon, and only if you are east of the Appalachian Mountains’ longitude (roughly), otherwise it was January 31st….
February 2 Jupiter lies 4 degrees north (upper right) of the thin evening crescent moon. The only evening planet and Mon conjunction we have this month, or for much of any time this spring.
February 8 First Quarter
February 9 If you are a Reader in Southeast Asia, Japan, Korea or the like, you can watch the Moon glide over Asteroid #1, Ceres.
February 11 The Moon is at apogee, at its farthest orbital point from Earth, not quite a so-called Micro-Moon since it is Full yet, but whatever….
The Moon is a guide to a group of four winter star clusters, though you’ll need to binoculars to find them with the bright moon so close. But if you memorize the positions and look a few days later, you’ll see the beautiful groups of stars, all young families of only a few millions of age.
February 9 The Moon is between the Pleiades and the V-shaped Hyades that marks the face of Taurus the Bull.
February 12 The Moon passes about 2 degrees from M35, in the Gemini Twins western foot. Look below the Moon.
February 14 The Moon passes north of the Beehive star cluster, a much older and looser group.
Observing---Plan-et….
Pretty much all the solar system action — but one event — is in the dawn.
Mercury has entered stage left (East, that is) in the dawn already, and is giving Earth’s Southern Hemisphere observers its best show of the year, but it isn’t bad for the Northern sky-watchers either. You can see brilliant Mercury rise just after morning twilight begins starting about the 7th. The planet reaches its greatest brilliance on the 14th, two days before its maximum angular distance (elongation) from the Sun.
Venus last month, rocketed into the dawn sky and quickly into rising before morning twilight, and now…..gets lazy. By the 14th it rises about an hour before morning twilight, and never increases hat gap. It does get about as bright as it ever gets, magnitude -4.9, bright enough to cast your shadow if you are away from city lights, on the 12th, and also passes Mars by a healthy 7 degrees, Mars a mere red dim flicker by comparison.
Mars continues its rising about 30 minutes before morning twilight begins…and tagging alongside respectfully to big sister Venus for the next several months. Then, when Venus moves sun-ward, Mars makes its move to prominence.
If you make Venus the center of an analog clock face, Mars will be on an ‘hour hand’ starting at the 4 o’clock position and rotating almost to the 6 o’clock spot below Venus this month. Mercury, on the other, er, hand, will always be on a stuck minute hand way at the 7 o’clock angle, and starting as close as 13 degrees away, but that length basically doubles before it disappears at month’s end. The hand stretches but doesn’t move…..
Jupiter has the evening essentially to itself, but on the 8th, it sets when twilight ends and that means in the next two weeks afterwards, you’ll have to look for it in twilight, before it is gone until summertime.
Saturn, on a rest break.
Last TheGalactic Times issue (and in more detail in The Classroom Astronomer #17) we discussed observing Algol, in Perseus, the best eclipsing binary star for beginners. There’s another minimum brightness eclipse to look for, centered around 10 PM Central Time US, on the 12th. The eclipses last about 2 hours and some minutes so to see the star out of eclipse, look more than 2 hours on each side of 10 to see the changes.
Border Crossings - Be a Valentine’s Day Goat, er, GOAT…
February 14th, Valentine’s Day for your sweetheart. But for this two week period, as well as for this one day, traditionally your sweetheart is an Aquarius. But the Sun is really in Capricornus (the Sea Goat) this whole 14 day period! So if you buy jewelry for Valentine’s Day, you could be loving, and scientifically literate, by getting him or her an image of Capricornus, any day right through the 15th…… perhaps you’ll be a GOAT with your lovey (that is, Greatest of All Time).
The Classroom Astronomer Newsletter Issue 18 Highlights
This premium Inbox Magazine is a subscribers-only publication, though a free Lite version is available. Starting in January, it became a 30-issues per year publication, and the Lite version, now called the TCA Digest, became a monthly on the last day of each month.
Welcome to Issue 18!
(Cover Story) Article - Making What Already Exists Accessible, Astronomy Labs for the Blind and Visually Impaired
Sky Lessons - A Progression of Star Clusters
The RAP Sheet – Research Abstracts for Practitioners - Which One Is More Effective in Teaching the Phases of the Moon and Eclipses: Hands-On or Computer Simulation? - We Know the Way: Learning the Secrets of Celestial Navigation from Ancient Travellers
Articles for The Galactic Times Newsletter are welcome. So are sponsorships and advertisements. Query us at the email address below!
You can most help support this publication by subscribing not only to The Classroom Astronomer above, but also by purchasing other books or products from the Galactic Times’ parent company Hermograph Press. Click here to head to Hermograph’s home page.
This newsletter is (c) 2022 Hermograph Press LLC, Opelika, AL. All rights reserved. No part of this may be reproduced without permission in any other medium, such as newspaper columns, webpages, blogs, etc. Please contact the undersigned for permissions, etc., and do not feed the hungry lawyers…….
