Category Archives: Stars
From a “mere” 93 million miles away we’re able to view the surface of our home star the Sun very well with telescopes on Earth and in space…you can even observe large sunspots with your unaided eye (with proper protection, of course.) But the surface details of other stars tens, hundreds, or thousands of light-years away can’t be so easily resolved from Earth. The details are just too fine and get lost in the brilliance of the stars themselves.
But astronomers have now produced the best image yet of the surface of another star beyond our Solar System. Using the European Southern Observatory’s Very Large Telescope Interferometer, located on a high plateau in Chile’s Atacama Desert where the sky is some of the clearest and driest in the world, a team of scientists have mapped the movement of material in the atmosphere of Antares, a red supergiant star 700 times the size of our Sun that shines brightly in the heart of the constellation Scorpius. The observations enabled them to determine how material moves through Antares’ atmosphere and then construct an image of the star itself—the most accurate representation of another star besides the Sun.
Like people, stars are found in all colors and sizes. They can range from small, sassy red dwarfs to giant blue beasts. In fact there are seven main types of stars, grouped by their apparent colors (and thus temperatures) and classified as O, B, A, F, G, K, or M in order of hottest to coolest. (Learn more about that here.) The video above, released by The Royal Observatory in Greenwich, England, gives a brief life history of three of the most common types of stars found in our galaxy: blue O stars, red M dwarfs, and yellow G stars—the latter of which being the class of our own Sun. It’s really fun, cute, and educational—check it out, and also find more videos on The Royal Observatory’s Vimeo page.
Like anything else, stars have life spans. They are born (from collapsing clouds of interstellar dust), they go through a long main phase where they fuse various elements in their cores, and eventually they die when they run out of fuel. The finer details of these steps are based on what the star is made of, how massive it is, and what sort of company it keeps. Stars like our Sun have lifespans in the 9-10 billion year range—of which ours is near the middle—but other stars can have much shorter or longer lifespans, and as astronomers look out into the galaxy they can find stars at all different phases of their lives…of course, the longer a phase lasts, the more likely it is to find stars existing within it. We’ve found stars that are only a few thousand years old and we know of regions where stars are, right now, in the process of being born, but what is the oldest star we know of?
Actually, it’s not all that far away, in cosmic terms. Just 190 light-years distant in our own galaxy, HD 140283 (aka the Methuselah star) is, as of 2013, the oldest star ever discovered. Based on its stage as a subgiant and its remarkably low amount of heavy elements, astronomers have estimated the age of this star as 14.3 billion years old. Now this number is actually more than the estimated age of the Universe itself, but don’t worry—there’s a reason for that.
Read the rest of this story by astronomer Phil Plait on Slate here: The Oldest Known Star in the Universe.
It hasn’t even been found yet (they’re still working on that) but the recently-announced Planet Nine is already spurring discussion amongst the world’s astronomers. One of the recent topics surrounding this alleged new planet is (again, besides where it’s hiding) how it formed and how it got into the incredibly distant orbit it’s thought to be in. Estimated to be nearly as massive as Neptune, and possibly similarly gaseous as well, Planet Nine would be an anomaly among the small frozen balls of ice that typically haunt the outer Solar System. Recently, a team of scientists decided to investigate the possibility that Planet Nine did not originate in our Solar System at all but rather was captured from another star, back when the Sun’s stellar family was much closer together… and apparently much more trusting. (That’ll teach ’em.)
Neutron stars are strange cosmic beasts. Stellar corpses that are several times the mass of our Sun but only about the width of Manhattan, they can contain a mountain’s worth of star-stuff within the space of a sugar cube, creating all sorts of weird physics that requires funny-sounding names like “quark-gluon plasma” to even try to describe what’s going on. The video above, created by Munich-based design studio Kurzgesagt (which means “in a nutshell” in German) illustrates how neutron stars form and what we think is happening on, around, and inside them.
See more In a Nutshell videos by Kurzgesagt on YouTube here, and find some interesting neutron star facts below: