TGT #35 - The 13th Constellation of the Zodiac Houses the Sun!; + 7 more [Nov. 16, 2022]
This Just In--Gold Stars, Black Holes in Dwarf Galaxies, Star Core You Can See, A STRANGE Star; Sky Calendar--Leo and Its Meteors Washed Out, Mars About to Peak, Sun Enters 13th Zodiac Sign!.
Cover Photo - Signs 9, 10 and 13
In This Issue:
Cover Photo — Signs 9, 10 and 13
Welcome to Issue 35!
This Just In —
- Boys and Girls, Would You Like a REAL Gold Star?
- Black Holes in the Centers of….Dwarves?
- In the Current Night Sky: That’s No Star You See, That’s a Star’s Inner Core.
- A Strange Star That is…REALLY Strange…
Sky Planning Calendar —
* Moon-Gazing - Leonid Meteors and Leo’s Mouth Washed Out By the Moon.
* Observing—Plan-et - Mars Coming to its Peak, Inner Planets Huddle in Sun’s Glare Sight Unseen
* Border Crossings - The 13th Constellation of the Zodiac Houses the Sun! Teach With It! (Cover Story)
Astronomy in Everyday Life — Dino, Meet Asteroid!
The Galactic Times — InDepth Inbox Magazine Highlights!
The Classroom Astronomer Issues 39 & 40 Topics
Welcome to The Galactic Times Newsletter-Inbox Magazine #35 !
In this issue of The Galactic Times, the sky is quiet, but leading up to a brilliant end-of-year show! Mars is taking center stage, get your scopes out!
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Our newest publication, The Galactic Times — InDepth explores a topic in each issue, as stated, in depth, like a New York Times Sunday Magazine piece, rather than running a story over two or more regular Galactic Times issues. The first issue tours a crater—actually three tours into it—and see features on the landscape, in this case, the ~6-mile diameter Wetumpka, Alabama crater. The article has maps, instructions and photos, and also what else is in the area in order to make a real trip out of the experience. As the article will be longer than a regular issue, the issue has a downloadable PDF link for subscribers.
December’s issue will be on the Gaia mission with the point on answering the question, what’s really above us? —an article on Polaris and the true North Celestial Pole, and other poles, and following that is expected to be one on Star Trek astronomy. Interviews, possible short podcast excerpts, in-depth summary articles based on plenaries and talks at astronomy and astronomy education conferences, and articles authored by others are also anticipated (and requested!).
InDepth will be a premium publication. It will start as a monthly magazine with an occasional bonus issue as topics warrant. The introductory subscription through Substack will be $18.00 per year. For more information, go to https://www.thegalactictimes.com/indepth and subscribe at https:/tgtindepth.substack.com .
Click here https://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 on the website (plus links to other Hermograph products and periodicals).
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Publisher — Dr. Larry Krumenaker Email: firstname.lastname@example.org
This Just In —
* Boys and Girls, Would You Like a REAL Gold Star?
From an early age students are taught to be eager for gold—gold stars, that is. You learn something in class, or are well-behaved, you get a gold star sticker. Good boy, good girl! Sometimes we even talk about the golden light of the stars (really???). But are there really stars with gold in them? According to Yutaka Hirai, of Tohoku University, there are hundreds out there, if only you can get to them.
There are hundreds of so-called “jewelry store stars,” stars with elements heavier than iron, that includes gold and platinum elements, in them. But these elements are not normal, in that they aren’t part of the regular day-to-day fusion process powering a star. Where do they come from? The answer, he found, was in the building blocks that constructed the early Milky Way galaxy. Our jewel of a spiral galaxy was put together with small building block galaxies that are still colliding with the Milky Way (jewels in the milk!) and these had stars enriched with gold.
The team found that most gold-rich stars formed in small progenitor galaxies of the Milky Way over 10 billion years ago, shedding light on the stars’ past for the first time.
In order to reach this conclusion, the team tracked the Milky Way's formation from the Big Bang to the present with a numerical simulation. This simulation has the highest time resolution yet achieved - it can precisely resolve the cycle of materials formed by stars in the Milky Way. The simulation was produced over several months using the ATERUI II supercomputer in the Centre for Computational Science at the National Astronomical Observatory of Japan.
Each time neutron stars merged – according to simulations covering 10 billion years—neutron star mergers being a confirmed site of heavy element nucleosynthesis – the abundance of the heaviest elements in these small galaxies increased. The gold-rich stars formed in these galaxies, and their predicted abundances can be compared with the observations of the stars today.
It will be interesting to see what science fiction writers come up with to locate the nearest of these stars and have spacefarers mine them for gold! [Wanajo et al., Neutron Star Mergers as the Astrophysical Site of the r-Process in the Milky Way and its Satellite Galaxies’, Monthly Notices of the Royal Astronomical Society, in press.]
* Black Holes in the Centers of….Dwarves?
It is well-known now that there are massive black holes (BHs) in probably all major big galaxies. There are lots of stars colliding and exploding as supernovae, creating massive BHs in their centers. But there are far more dwarf galaxies in the universe; there are dozens in the Local Group surrounding the single Milky Way. Are they massive enough to have black holes in their centers? Nobody’s ever seen any evidence. Until now.
Identification of black holes systems in galactic centers has historically relied on the detection of light emitted from accreting gaseous disks close to them; otherwise they are all but impossible to detect. The only other way might be tidal disruption events, when luminous flares occur as a star strays too close to a BH and gets shredded. As the flare brightness rises, the time that that takes theoretically correlates with the BH mass.
A recent fast-rising tidal disruption event, AT 2020neh, hosted by a dwarf galaxy, can be described as the tidal disruption of a main sequence star by a 10^4.7–10^5.9 M⊙ Black Hole. This event is rare, perhaps the first of its kind. [Angus, C.R., Baldassare, V.F., Mockler, B. et al. A Fast-Rising Tidal Disruption Event from a Candidate Intermediate-Mass Black Hole. Nature Astronomy (November 10, 2022). https://doi.org/10.1038/s41550-022-01811-y]
* In the Current Night Sky: That’s No Star You See, That’s a Star’s Inner Core.
Hiding below the feet of Orion the Hunter, perhaps hoping to escape his gaze, are two animal constellations, Lepus the Hare, and lower still, Columba the Dove. And in the latter is a blue-white B-type star, Gamma. But what you see isn’t your usual B-star, with a hot hydrogen-helium outer shell and atmosphere, surrounding an even hotter but invisible to our eyes inner core where atomic fusion takes place. What you see is just the inner core where atomic fusion takes place! Somehow, the outer atmosphere has been stripped away and we have a rare glimpse of the inner core of the star itself.
Stellar cores are the central regions where densities and temperatures are high enough for nuclear fusion processes to take place. Normally, a core is exposed only in O-type Wolf–Rayet or helium hot subdwarf stars, all extremely rare. Gamma (γ) Columbae is neither; it is the pulsating core alone (with a mass of 4–5 M⊙) leftover from a previously much more massive star of roughly 12 M⊙ that just finished central hydrogen fusion.
Gamma Columbae may be labeled as the third brightest star in the small constellation but it is fainter, at magnitude 4.4. It is distant, at nearly 900 light years. The bulk of Columba, rising near midnight local time, consists of a small triangle, like an inverted measuring spoon; Gamma is a star on its handle to the east just a short distance away. [Irrgang, A., Przybilla, N. & Meynet, G. γ Columbae as a Recently Stripped Pulsating Core of a Massive Star. Nature Astronomy (October 31, 2022). https://doi.org/10.1038/s41550-022-01809-6]
* A Strange Star That is…REALLY Strange…
Let’s see, how do stars end? Low mass stars just fade away as white dwarfs which become (someday?) black stars, right? Bigger stars become supernovae and are either totally destroyed or become neutron stars, right? What happens in between neutron stars and white dwarf stars?
The theoretical lower limit for a neutron star is supposed to be around Chandrasekhar’s limit of 1.4 solar masses, below which the star can just pulse off the outer atmosphere and become a white dwarf and above which the star supernovas. A few neutron stars have been found slightly below the limit for presumably outside influences. Say, 1.2, or 1.17 solar masses.
Either something played whack-a-mole with this supernova remnant or something else happened in the explosion. Unlike a lot of remnants, this one has a couple of factors that are better known than most, like its distance. There is a companion star and its distance AND the supernova dust and gas are both known accurately due to measures made by the Gaia satellite. When everything is taken together, it may be that at least part of this object may be not just neutrons but a mixture of neutrons and…those sub-sub-atomic particles that make up neutrons and other particles called… quarks! Strange…matter indeed! [Doroshenko, V., Suleimanov, V., Pühlhofer, G. et al. A Strangely Light Neutron Star Within a Supernova Remnant. Nature Astronomy (October 24, 2022). https://doi.org/10.1038/s41550-022-01800-1].
Sky Planning Calendar
Isn’t it amazing what today’s cell phone camera’s can do?…
The rest of this month is fairly quiet, following two eclipses, one solar, one lunar, we need to catch a breath, right? But we have three phases in this fortnight….
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.
November 16 Last Quarter. In North America, you’ll find the Moon near the Sickle of Leo and above Regulus, the bright heart of the Lion, Leo. That’s unfortunate, as the next three nights, that is too close to where the Leonid meteors will stream from. While it is not the best place to look for meteors, the radiant point where they stream from, it does rather make for washing out the shower all over the sky anyway. Every 33 years the Leonids does get pretty active, from its measly 20 per hour to hundreds or thousands, but this year it will be hard put to even get that 20 visible with the Moon light washing out the Lion’s mouth.
November 21 Locate the thinning crescent this morning to the lower left of Spica in Virgo.
November 23 New Moon.
November 26 The Moon is at Perigee; we’ll have a Super-Three-Day-Old Crescent Moon!
November 28-29 The Moon passes 4-degrees south of Saturn, but when depends on where on Earth you are. In North America it is around midnight—setting time or after that—on the 28th.
November 30 First Quarter Moon.
Mercury and Venus are still lost in the solar glare, trying to enter the evening sky, but won’t take any kind of stage until next month, and a poor stage it will be then. Both of them actually are in a kind of quasi-conjunction on the 28th, when they set at the same moment, 30 minutes after sunset, but you’d have to have super-clear horizons and skies and precisely point-able telescopes to find them in the still bright twilight.
Earth-lings get one local event to observe. As noted above, there is an otherwise major meteor shower, the Leonids this month, but it isn’t really worth much of your time. Peaking on the midnight between the 17th and 18th, it nevertheless has a just-past Last Quarter Moon flooding the sky with light, and the radiant area near Leo’s head is where said Moon lies. You want to look at least 90-degrees from there to even have a chance, and then closer to dawn hours to have any chance to see the few fireballs, swift and bright.
Mars is about to take its moment in center stage. On the last day of November it is closest to Earth, so close that its smaller-than-Earth disk appears 17.1 arc-seconds in size in a telescope, which is actually bigger than second-biggest-planet Saturn’s 16.9”! (That’s not counting the rings.) You will not have any trouble finding it—Mars is rising just after sunset in the ENE as the brightest fiery-red star amongst the entering-the-sky winter constellations, a brilliant magnitude -1.8, brighter than Sirius, and just one magnitude less than Jupiter.
Jupiter grinds to a motion halt on the 24th and resumes normal eastward motion afterwards. The Moon is edging up to it at month’s end, see below.
Saturn, westward-most of the bright outer planets, sets around 10 PM at month’s end. Fading a bit, it still is not too hard to find in a bright-star-less desert west of Jupiter, but it will be near the Moon on the 28 and 29th.
For the Future
A quasi-conjunction of inner planets was mentioned above. A real one happens in December, when Mercury and Venus pass each other (one going sun-wards, one exiting the Sun’s glare slowly) one month from the quasi-…
Mars has a fantastic December, coming to opposition a week after closest approach to Earth, and the Moon coming TOO close—actually passing over the planet in prime evening time over North Americans—a neat show! Details in the next TGT issue.
Jupiter is passed by the Moon on December 1st, though not so closely as Mars gets it!
Now comes the time of year that I most astrologically loooooooove…..especially as a teacher.-LK
The Sun, according to astrologers, is in Scorpio (Scorpius!!) until the 21st, when it enters Sagittarius. Not quite, guys! It actually enters Scorpius on the 23rd. BUT!…
It is only amongst those stars for….hold on….wait for it…..seven days. Yes, one week. Half a fortnight. The 23rd through 29th (Happy Thanksgiving, Scorpions!). Then… the Sun crosses the border into…..
You don’t see this one in the newspaper horoscopes, do you? Not much future in being a handler of snakes, I guess. But astronomically, the Sun spends more time in THIS constellation than it does in the Scorpion! Almost 3 weeks.
The constellations of the zodiac are those star groups that the Sun’s path, the Ecliptic, goes through in the sky. And there are thirteen of them (and there’s more, wait for it below). Ophiuchus, the handler of snakes and the celestial avatar of Aesclepius, the first doctor, has one foot pushing down on the back of Scorpius, whereas the Sun only goes through one of Scorpius’ narrow claws before it exits enter the good Doctor after a week (See the Issue Cover Photo). But 13 wasn’t a lucky number to the Greeks, and 13 constellations don’t divide up the ecliptic evenly (nor are they the same sizes), nor do they then match up with the 12 months (more or less formed by the 12 moon phase cycles—another ignored oopsy, calendrically). So Ophiuchus was ignored.
It also shows that if you, a human, make up completely artificial star patterns that have absolutely no reality in nature—human-made constructs—you have to be daft to expect them to have any real say or control over your life.
Sorta like fake news.
Oh, and as far as the Sun signs go, there are actually 14; the Sun touches one for about a day in March—Cetus the Sea Monster. We’ll talk about THAT then.
And as for how this helps in teaching…..
I’ve always said, if you can’t get the current sky right in the present, how can you possibly correctly predict the future? Often in teaching astronomy, the Ecliptic comes up—in coordinate lessons, where are the planets tonight lessons, and so on. Somewhere along the way, I “innocently” ask about students’ ‘signs’ which garners a lot of interest. I can very easily segue into stating that I think most of them have the wrong signs for their dates, and after getting them to agree that a “sun sign” is the constellation the Sun is in on the day you were born, I wager them that they are incorrect and put down some real money and ask for takers of my bet. At the college level I usually get a few. Then I have them write down on a piece of paper their name, birthdate (but not year), the sign they read (I’m a Virgo!), and a blank line. They roll the paper up into a ball really tight, and put all the papers into my hat. I shake the hat up, mixing the balls well, and then redistribute the balls by letting the students draw one out of the hat, but not open them up right away. Using our agreed sun sign definition I discuss the constellation borders (Border Crossings, hint hint, get it?) and tell them how easy it is to determine them and then I project on the screen or board the list of dates when the Sun enters and leaves the 14 constellations. THEN they open the balls of paper and check the paper of the person they got (i.e. not their own), and fill in the blank with the actual ‘sign’. (There are ALWAYS audible gasps <grin>.) By show of hands I have the writers show how many slips of paper have the written sign match the actual sign; these I have to pay with my bet money.
I always win. Six out of seven on average in any class will be wrong. [I say I will pay the winners after the losers pay me.] Those I have to pay money are always fewer than those who have to pay me. Why? 1) For the reasons stated before—14, not 12 constellations, uneven ‘sign’ sizes. 2) The wobbling of the Earth’s north pole in its motion called precession, which changes the direction it points to [today, near Polaris, several thousands of years ago when the zodiac constellations were made—near Thuban in Draco the Dragon (not Draco the Slytherin)] which shifted the constellations today to new locations and thus new solar entry and exit dates. The number of days that match are about one in seven.
And, for ethical reasons, since my night astro classes were usually long, I always use the money to order deliveries of pizza for during our mid-class break. And it usually mollifies the losers as well as making a good educational (and hopefully, life) lesson.
Astronomy in Everyday Life
Couldn’t pass this up — artwork in Wetumpka, AL in the downtown area. The town borders a 5-mile diameter meteor crater and a restaurant has this painting on its outside wall.
The Galactic Times InDepth Newsletter-Inbox Magazine
For Information and Previews, Click
Issue 1—November 2022 Space Tourism on Earth - A Visit to a Crater (Article Available as a PDF for free in the online preview).
Issue 2—December 2022 What’s Above Us? An Examination of the Gaia Mission and Exploring the Question, What Stars are REALLY above the Earth and the Solar System?
The Classroom Astronomer Newsletter - Inbox Magazine Issue 39 & 40 Highlights!
These two issues are currently being written but won’t be finalized until after TGT 35 goes out. Yours truly is attending the virtual IAU Shaw Astronomy Education conference out of Heidelberg, Germany (my European home town!) and most of the stories will come from that. One issue will be for premium subscribers, with conference reports, and the other will be the monthly free subscribers issue, with Sky Lessons and Connections to the Sky resources.
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