Thursday Throughput: AAS Bumper Crop Edition
Hold on to your hats, folks. It’s gonna be a long one this week. Right now, in Hawaii, the 235th meeting of the American Astronomical Society is going on. That means lots of press releases about really cool results. By the time this posts, I expect another five or six cool results to be announced. So let’s tuck in.
[ThTh1] This week’s “Ask an Astronomer” comes from long-time Twitter follower Rob Prather, who asks, “Is there a simple way to explain how a planet orbits two stars? I get the intuition on just one.” As it happens, we just had a discovery of a planet orbiting around two stars.
As for how it works. When you have two bodies in orbit around each other, the physics is pretty straight forward. They orbit with the same period around a common center of mass — a point where the weighted mass distribution balances out. That point is closer to the heavier object. So if you consider just the Earth and the Sun, they both orbit around each other. But the Sun is much more massive than the Earth, that point of balance is inside the Sun itself. The Earth orbits around the Sun and the Sun “wobbles” slightly in response to the Earth. Many planets have been detected this way: by the wobble of their host star.
When you have multiple bodies, however, the math gets really complicated. But, most of the time, we don’t worry too much about that. The gravitational forces in our Solar System, for example, are dominated by the Sun, which contains a thousand times as much mass as the planets combined. Other planets, like Jupiter, can have an effect on us, but it’s fairly minor.
But what if you have two stars? Then it gets complicated. The three-body interaction would make planetary orbits unstable and even eject some planets from such systems. But there are two areas where planets could exist in a stable orbit. If a planet were very close to one of the two stars, the nearby star would dominate and the effect of the more distant star would be fairly minor. In the case of TOI 1338, you have the other solution: if a planet is far enough away from its parent stars, their gravity would be effectively that of a single star. Using Kepler’s law, I estimate that the planet is about three times as far away from the two stars as they are from each other. That’s enough that its orbit changes a bit but it will still hang around for an indefinite time.
[ThTh2] This has to be seen to be believed. Pulsars are the shriveled husks of stars that went supernova. A typical pulsar would be the size of a small city, weigh 1.4-2.2 times as much as the Sun and spin about once a second. It would have a magnetic field so intense that if you tried to use a compass, the atoms in it would come apart. We’ve now gotten our first detailed look at the surface of a pulsar. And it’s incredibly messy and complex, with a tangled magnetic field that looks only vaguely like what you’d see in a textbook. Astonishing work here. Click through for the animation.
[ThTh3] Massive black holes are usually found at the center of their parent galaxies. But not always.
[ThTh4] Fast Radio Bursts — short intense radio signals from the cosmos — have long been a mystery. But we’re slowly learning more about them. And now we’ve found where one of them is coming from. I’m not saying that it’s aliens but…it’s probably not aliens.
[ThTh5] So will eating Impossible Whoppers give men breasts? In a word: no. Soy contains hormones that are similar to estrogen. It is theoretically possible that if a man consumed a lot of faux burgers, it would cause hormonal problems. But he’d have to consume A LOT of soy. As in a gallon of soy milk a day or 5-10 soy burgers a day. And if you’re eating 5-10 Whoppers a day, you’ve got bigger problems.
[ThTh6] The better out telescopes get, the more amazing our Galaxy gets:
A cluster of newborn stars was found on the outskirts of the Milky Way by @FlatironCCA's Adrian Price-Whelan (@adrianprw) & colleagues. Presented today at #AAS235. The gif shows position of the stars relative to our galaxy & the Magellanic Clouds. For more https://t.co/ABDRxZqH3W pic.twitter.com/KUd9jETJ66
— Flatiron Institute (@FlatironInst) January 7, 2020
[ThTh7] Yep. That’s how science works.
I produced a tribute to my wrongness. pic.twitter.com/1aJRAUJlIm
— That’s Dr. Monkiewicz to you (@jmonkiew) January 6, 2020
[ThTh8] Is streaming TV shows destroying the planet? Probably not. I clicked through to the original publication which is less of a scientific research paper than a screed. It’s true that the energy needs of data centers is a growing concern. But … at most, we’re looking at about 4% of energy use for all technology, including manufacture. Data centers are 20% of that, so less than 1% of global energy use. That will increase over the next few decades but will still be small. So their calls for “digital sobriety” seems badly misplaced. The real challenge here is to decarbonize the electrical grid. Do that and you can binge-watch all you want. In fact, you can do it now; the energy will be dwarfed by what you’re using just to keep your house running.
I’ve talked about this before, but I’ve grown a bit tired of these occasional bulls from the Church of Climate Shaming. I don’t think it motivates anyone. It’s simple puritanism; deciding that if people enjoy something it must be bad and must be sacrificed on the altar on environmentalism. But I don’t find that it motivates people. It either makes them ignore the problem or give up hope (so much so that some activists think that’s the point).
As I mentioned in my post on straws, we need to focus on big picture things, not tiny details that only matter on the fringes. Those problems are hard enough to solve without making anyone feel guilty because they watched His Dark Materials.
[ThTh9] And speaking of global warming, Germany has phased out their nuclear plants. The result? Much burning of coal with billions in social costs, hundreds of death from pollution and a warming planet. The deaths alone will be anywhere from 10-100 times what Fukushima cost us…every year.
Nuclear is part of the solution. We need to keep pretending it isn’t because radiation scares us.
Absolutely beautiful video created using still images taken by the Cassini spacecraft during its flyby of Jupiter and while at Saturn. Shown is Io and Europa over Jupiter's Great Red Spot and then Titan as it passes over Saturn and it's edge-on rings. Credit NASA/JPL/Kevin M.Gill pic.twitter.com/CrIPHxtsld
— Domenico Calia (@CaliaDomenico) January 1, 2020
[ThTh11] A wonderful visualization:
To count an animal population if you can't catch them all: capture some, mark them, release, and capture again. The ratio of new vs already seen tells you something about the total number. Shown here is iterated mark-and-recapture with a Bayesian updates to belief about pop size pic.twitter.com/jZF7HXddiq
— Andrew M. Webb (@AndrewM_Webb) January 2, 2020
[ThTh12] And another:
Over the last five years I've collected eclipses with this single composition in mind. I call it "Cyclipse". It's made of a total solar eclipse, partial solar eclipse, total lunar eclipse, and waxing crescent Moon. It feels so good to see it come together over the years. #eclipse pic.twitter.com/FkQkzQShzp
— Marc Leatham (@quarkmarc) December 28, 2019
[ThTh13] You know I love me some optical illusions:
For the hungover…Hypnotic. Each ball is moving in its own straight line pic.twitter.com/n1hUj5oufH
— Bernie'sTweets (@berniespofforth) December 26, 2019
[ThTh14] And I’ll close this one out with yet another discovery from the world of exoplanets: an Earth-sized planet in the habitable zone.