Space isn't remote at all. It's only an hour's drive away if your car could go upwards.

— Fred Hoyle

Hubblesite Newscenter

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This news collection compiles news releases and supporting materials published by the Officeof Public Outreach of the Space Telescope Science Institute, to further your knowledge of astronomy. The different news releases are organized by space telecope (Hubble, James Webb, WFIRST, etc.), and different categories (like galaxies, nebulae, planets, stars, etc.).
Updated: 12 hours 50 min ago

Hubble Solves Mystery of Monster Star's Dimming

Thu, 03/04/2021 - 11:00am

Stars come in an extraordinary range of sizes. One of the most colossal is VY Canis Majoris. If placed in the middle of our solar system it would engulf all the planets out to Saturn's orbit. This monster, appropriately called a red hypergiant, is as bright as 300,000 Suns. Yet it is so far away that, 200 years ago, it could be seen only as a faint star in the winter constellation of the Great Dog. Since then, it has faded and is no longer visible to the naked eye. Astronomers used Hubble to get a close-up look at the star and discovered the reason for the dimming. The star is expelling huge clouds of dust in the final stages of its life. Eventually, the bloated star may explode as a supernova, or may simply collapse and form a black hole.

Categories: NASA

Comet Makes a Pit Stop Near Jupiter's Asteroids

Thu, 02/25/2021 - 12:00pm

Long road trips can be tedious and boring. That's why many road travelers break up their arduous journey by making rest stops along the way.

Astronomers found that at least one roaming comet is doing the same thing. The wayward object made a temporary stop near giant Jupiter. The icy visitor has plenty of company: It has settled near the family of captured asteroids known as Trojans that are co-orbiting the Sun alongside Jupiter.

This is the first time a comet-like object has been spotted near the Trojan asteroid population. Hubble Space Telescope observations reveal the vagabond is showing signs of transitioning from a frigid asteroid-like body to an active comet, sprouting a long tail, outgassing jets of material, and enshrouding itself in a coma of dust and gas.

The interloper came from the frigid outskirts of our solar system, a comet nesting-ground called the Kuiper Belt. This nomad was likely snatched by Jupiter's powerful gravity after it had a brush with the giant planet.

Jupiter's uninvited guest probably will not hang around the planet for very long. As the "bouncer" of the solar system, the monster planet's gravitational tug will eventually boot the comet back onto its road trip toward our Sun.

Categories: NASA

Hubble Uncovers Concentration of Small Black Holes

Thu, 02/11/2021 - 10:00am

The idea that black holes come in different sizes may sound a little odd at first. After all, a black hole by definition is an object that has collapsed under gravity to an infinite density, making it smaller than the period at the end of this sentence. But the amount of mass a black hole can pack away varies widely from less than twice the mass of our Sun to over a billion times our Sun's mass. Midway between are intermediate-mass black holes (IMBHs) weighing roughly hundreds to tens of thousands of solar masses. So, black holes come small, medium, and large.

However, the IMBHs have been elusive. They are predicted to hide out in the centers of globular star clusters, beehive-shaped swarms of as many as a million stars. Hubble researchers went hunting for an IMBH in the nearby globular cluster NGC 6397 and came up with a surprise. Because a black hole cannot be seen, they carefully studied the motion of stars inside the cluster, that would be gravitationally affected by the black hole's gravitational tug. The amplitudes and shapes of the stellar orbits led to the conclusion that there is not just one hefty black hole, but a swarm of smaller black holes – a mini-cluster in the core of the globular.

Why are the black holes hanging out together? A gravitational pinball game takes place inside globular clusters where more massive objects sink to the center by exchanging momentum with smaller stars, that then migrate to the cluster's periphery. The central black holes may eventually merge, sending ripples across space as gravitational waves.

Categories: NASA