Philip Plait's Blog, page 27

NGC 4394: A gorgeous galaxy with a built-in bar

I really, really wish that one day I could throw out a spectacular image of a sprawling spiral galaxy and just say, "Here. HERE. LOOK AT IT. LOOK AT ITTTTT!"

But I can't. I just can't.

So first, yes, here. HERE. LOOK AT ITTTT.

The spectacular barred spiral galaxy NGC 4394, seen by Hubble Space Telescope. Credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt (Geckzilla)

Oof. Wow. So what is it?

That is a Hubble Space Telescope image of NGC 4394, a galaxy about 55 million light years from ...

The rise and rapid fall of the Stingray Nebula

Astronomy tends to have a timeless feel to it. Stars take millions of years to be born, a given galaxy will look exactly the same today as it did at the height of the Maya empire, even the constellations in the sky look pretty much the same as they did when Indigenous Australians started weaving their stories about them so very long ago in human terms.

Sometimes, though, things happen on a much faster timescale. The Stingray Nebula can lay claim to two such rapid events: It probably only starte...

Chinese radio telescope finds hundreds of new pulsars

After the collapse of the Arecibo radio telescope platform last year, the largest single-dish radio telescope in the world is China's Five-hundred-meter Aperture Spherical radio Telescope (or FAST), and it's been producing some interesting science.

One of its key projects is to survey the sky and map out faint pulsars: Spinning neutron stars that send out beams of energy as they spin. Like a lighthouse, if the beam sweeps over Earth we see a blip, a pulse of energy from them.

This guy has a wh...

A hidden planet reveals itself by yanking on its neighbor

In 1990, not a single planet outside our solar system was known. Now, not only do we know of thousands, but we have also have an almost embarrassing number of ways to find them.

You may have heard of the transit method, where a planet passes in front of its star, and we see a dip in the amount of starlight, like a mini-eclipse. This is the most successful method so far, and gives us the radius of the planet. You may also know the radial (or reflex) velocity method, where a planet tugs on its st...

The first lone neutron star ever seen outside the Milky Way

It doesn't happen too often, but sometimes I'll see a press release and/or read a paper reporting a first-of-its-kind observation that genuinely surprises me because I figured it would've been done long ago.

Going through some old emails, though, I saw a press release from a few years ago announcing astronomers had found the first lone neutron star outside our Milky Way galaxy.

My reaction was confusion. Neutron stars are the leftover cores of stars that explode as supernovae; the core collaps...

The delicate beauty of illuminated dust

Even the darkest cloud is a work of art, when it is illuminated sufficiently.

This is true on Earth even as it is in the heavens.

When stars die, sometimes after billions of years of creating energy and light in their cores, they can bloat up into swollen red giants, enormous and luminous objects. Silicon and carbon in their upper layers can blow out into the space around them, cooling and condensing into grains of material astronomers call dust.

The galaxy is littered with dense clouds of du...

Now we know just how far away a magnetar is

People think black holes are scary, and I get that, I really do. But to me, the scariest objects in space aren't black holes. They're magnetars.

These are a special kind of neutron stars, which are scary enough as is. When a massive star explodes at the end of its life as a supernova, only the outer layers are blasted away. The core collapses to form an unreasonably dense sphere about 24 – 28 kilometers across. This object can have a mass over twice that of the Sun but packed into a ball only a...

When two galaxies love each other very much…

Have you ever seen two galaxies in love?

Oh, at first there's the flirting from a distance, but then as they get closer the attraction gets stronger. They feel themselves drawn to each other, each with their arms extended toward the other. If circumstances aren't right they may pass each other, circling around in a lovers' dance, but the inevitably of their fate is to be together. Finally, slowly, they touch, wrap themselves around each other, and then, in the end, merge into one. The result: F...

Neutron stars may be quite a bit bigger than previously thought

It's a little bit weird how the very small is connected to the very large in our Universe. At some level it makes sense, since everything is made of subatomic particles, but in general the specifics of those particles is only important on incredibly small scales; on more human scales more macrophysical laws come into play and dominate.

But an experiment recently run on the size of a lead nucleus has big implications for neutron stars — literally. In a nutshell, the measurements of the nucleus o...

Deep sky survey shows the Universe is a teeny tiny bit smoother than expected

The enormous Dark Energy Survey (or DES) of the sky is yielding scientific results, and while for the most part they seem to align with what is predicted by cosmological models of the Universe's behavior, there are some interesting numbers that seem to indicate the cosmos not exactly what we expect. It's less clumpy.

The DES uses a four-meter telescope in Chile with a ridiculously huge 570-megapixel camera attached to it to take images of large swaths of the sky. Over the past three years — ove...