faint stars

When Dead Stars Collide!

Gravity has been making waves - literally.  Earlier this month, the Nobel Prize in Physics was awarded for the first direct detection of gravitational waves two years ago. But astronomers just announced another huge advance in the field of gravitational waves - for the first time, we’ve observed light and gravitational waves from the same source.

There was a pair of orbiting neutron stars in a galaxy (called NGC 4993). Neutron stars are the crushed leftover cores of massive stars (stars more than 8 times the mass of our sun) that long ago exploded as supernovas. There are many such pairs of binaries in this galaxy, and in all the galaxies we can see, but something special was about to happen to this particular pair.

Each time these neutron stars orbited, they would lose a teeny bit of gravitational energy to gravitational waves. Gravitational waves are disturbances in space-time - the very fabric of the universe - that travel at the speed of light. The waves are emitted by any mass that is changing speed or direction, like this pair of orbiting neutron stars. However, the gravitational waves are very faint unless the neutron stars are very close and orbiting around each other very fast.

As luck would have it, the teeny energy loss caused the two neutron stars to get a teeny bit closer to each other and orbit a teeny bit faster.  After hundreds of millions of years, all those teeny bits added up, and the neutron stars were *very* close. So close that … BOOM! … they collided. And we witnessed it on Earth on August 17, 2017.  

Credit: National Science Foundation/LIGO/Sonoma State University/A. Simonnet

A couple of very cool things happened in that collision - and we expect they happen in all such neutron star collisions. Just before the neutron stars collided, the gravitational waves were strong enough and at just the right frequency that the National Science Foundation (NSF)’s Laser Interferometer Gravitational-Wave Observatory (LIGO) and European Gravitational Observatory’s Virgo could detect them. Just after the collision, those waves quickly faded out because there are no longer two things orbiting around each other!

LIGO is a ground-based detector waiting for gravitational waves to pass through its facilities on Earth. When it is active, it can detect them from almost anywhere in space.

The other thing that happened was what we call a gamma-ray burst. When they get very close, the neutron stars break apart and create a spectacular, but short, explosion. For a couple of seconds, our Fermi Gamma-ray Telescope saw gamma-rays from that explosion. Fermi’s Gamma-ray Burst Monitor is one of our eyes on the sky, looking out for such bursts of gamma-rays that scientists want to catch as soon as they’re happening.

And those gamma-rays came just 1.7 seconds after the gravitational wave signal. The galaxy this occurred in is 130 million light-years away, so the light and gravitational waves were traveling for 130 million years before we detected them.

After that initial burst of gamma-rays, the debris from the explosion continued to glow, fading as it expanded outward. Our Swift, HubbleChandra and Spitzer telescopes, along with a number of ground-based observers, were poised to look at this afterglow from the explosion in ultraviolet, optical, X-ray and infrared light. Such coordination between satellites is something that we’ve been doing with our international partners for decades, so we catch events like this one as quickly as possible and in as many wavelengths as possible.

Astronomers have thought that neutron star mergers were the cause of one type of gamma-ray burst - a short gamma-ray burst, like the one they observed on August 17. It wasn’t until we could combine the data from our satellites with the information from LIGO/Virgo that we could confirm this directly.

This event begins a new chapter in astronomy. For centuries, light was the only way we could learn about our universe. Now, we’ve opened up a whole new window into the study of neutron stars and black holes. This means we can see things we could not detect before.

The first LIGO detection was of a pair of merging black holes. Mergers like that may be happening as often as once a month across the universe, but they do not produce much light because there’s little to nothing left around the black hole to emit light. In that case, gravitational waves were the only way to detect the merger.

Image Credit: LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)

The neutron star merger, though, has plenty of material to emit light. By combining different kinds of light with gravitational waves, we are learning how matter behaves in the most extreme environments. We are learning more about how the gravitational wave information fits with what we already know from light - and in the process we’re solving some long-standing mysteries!

Want to know more? Get more information HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com


A small, faint star relatively close by is home to seven Earth-size planets with conditions that could be right for liquid water and maybe even life.

The discovery sets a record for both the most Earth-size planets and the most potentially habitable planets ever discovered around a single star.

The strange planetary system is quite compact, with all of these worlds orbiting their star closer than Mercury orbits the sun, according to a newly published report in Nature.

“If you were on the surface of one of these planets, you would see the other ones as we see the moon, or a bit smaller,” says Michaël Gillon, an astronomer at the University of Liège in Belgium. “The view would be very impressive.”

Astronomers Find 7 Earth-Size Planets Around A Nearby Star

Images: NASA/JPL-Caltech


Every star is a sun as big, as bright, as our own. Just imagine, how far away from us you’d have to move the sun to make it appear as small and faint as a star. The light from the stars travels very fast. Faster than anything. But not infinitely fast. It takes time for their light to reach us. For the nearest ones, it takes years. For others, centuries. Some stars are so far away it takes eons for their light to get to Earth.

By the time the light from some stars gets here they are already dead. For those stars, we see only their ghosts. We see their light, but their bodies perished long, long ago.

- Episode 5: A Sky Full Of Ghosts, Cosmos: A SpaceTime Odyssey

Seven Worlds for TRAPPIST 1 : Seven worlds orbit the ultracool dwarf star TRAPPIST-1, a mere 40 light-years away. In May 2016 astronomers using the Transiting Planets and Planetesimals Small Telescope announced the discovery of three planets in the TRAPPIST-1 system. Just announced, additional confirmations and discoveries by the Spitzer Space Telescope and supporting ESO ground-based telescopes have increased the number of known planets to seven. The TRAPPIST-1 planets are likely all rocky and similar in size to Earth, the largest treasure trove of terrestrial planets ever detected around a single star. Because they orbit very close to their faint, tiny star they could also have regions where surface temperatures allow for the presence of liquid water, a key ingredient for life. Their tantalizing proximity to Earth makes them prime candidates for future telescopic explorations of the atmospheres of potentially habitable planets. All seven worlds appear in this artists illustration, an imagined view from a fictionally powerful telescope near planet Earth. Planet sizes and relative positions are drawn to scale for the Spitzer observations. The systems inner planets are transiting their dim, red, nearly Jupiter-sized parent star. via NASA


Milky Way over Uluru : The central regions of our Milky Way Galaxy rise above Uluru/Ayers Rock in this striking night skyscape. Recorded on July 13, a faint airglow along the horizon shows off central Australias most recognizable landform in silhouette. Of course the Milky Ways own cosmic dust clouds appear in silhouette too, dark rifts along the galaxys faint congeries of stars. Above the central bulge, rivers of cosmic dust converge on a bright yellowish supergiant star Antares. Left of Antares, wandering Saturn shines in the night. via NASA

Tony Stark/Iron Man - You Look So Familiar - Part 3

Originally posted by kolyafarrell

Series Summary: Tony runs into a 14-year-old girl outside of a coffee shop and spills his coffee. When she freaks out and tries to run away, he stops her and asks her if she’s okay and notices that she looks very familiar. He takes her back to the tower to get cleaned up and Natasha points out that she looks just like him. So, Tony tests her DNA and finds out she’s his.

Part Summary: Peter and Y/N talk about how Peter came to be the friendly neighborhood hero known as Spider-Man. They have their first date and go around the city. Tony gets a phone call that rocks his world.

Pairings: Tony x Daughter!Reader, Peter x Fem!Reader

Characters: Fem!Reader, Tony Stark, Peter Parker, Bruce Banner, Harold “Happy” Hogan, Liz Allan, Michelle, Ned Leeds. May Parker, Steve Rogers, Bucky Barnes, Natasha Romanoff, Wanda Maximoff, Vision, Sam Wilson, Thor Odinson, Clint Barton, James “Rhodey” Rhodes, Scott Lang, T'Challa (Mentioned)

A/N: Thank you to @mo320 and @molethemollie for being my betas!

You Look So Familiar Master List

Keep reading

I am the heart that smiles to the faint star, while the world is preoccupied with the moon.

Everyone probably knows this already, but I was reading up about binary stars and the page about Sirius mentioned:

What the naked eye perceives as a single star is a binary star system, consisting of a white main-sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, called Sirius B. The distance separating Sirius A from its companion varies between 8.2 and 31.5 AU. [x]

Petition for everyone to refer to OC as a “white dwarf” until Yana gives us a name.

Bill Denbrough: A Surprise Visit

Request  “can you write one for bill where him and the reader star gaze??? sorry it’s not much detail aaaaa ” - Anon

A/N  → I hope this is the kind of star gazing you meant. I have no idea where these kids would find a telescope.

Pairing → Bill Denbrough x Reader

Warnings  → none

Knock Knock.

You sat up with a start from your warm bed, and paused. Wide eyed and heart hammering. You pulled your blankets up to your chest, you could have sworn you left your door ajar. One of your parents must have closed it after checking on you. You weren’t sure how the small light from the hallway would have saved you, but the solid darkness in your room left a lot to be desired.

Knock Knock.

You whipped yourself out of bed quicker than you had ever moved before. You’re surprised you didn’t pull something.

“(Y-Y/N)” whispered a voice from outside.


Keep reading

Night Hides the World : Stars come out as evening twilight fades in this serene skyscape following the Persian proverb Night hides the world, but reveals a universe. The scene finds the Sun setting over northern Kenya and the night will soon hide the shores of Lake Turkana, home to many Nile crocodiles. The region is also known for its abundance of hominid fossils. On that past November night, a brilliant Venus, then the worlds evening star, dominates the starry skies above. But also revealed are faint stars, cosmic dust clouds, and glowing nebulae along the graceful arc of our own Milky Way galaxy. via NASA


Galaxies in Pegasus : This wide, sharp telescopic view reveals galaxies scattered beyond the stars and faint dust nebulae of the Milky Way at the northern boundary of the high-flying constellation Pegasus. Prominent at the upper right is NGC 7331. A mere 50 million light-years away, the large spiral is one of the brighter galaxies not included in Charles Messiers famous 18th century catalog. The disturbed looking group of galaxies at the lower left is well-known as Stephans Quintet. About 300 million light-years distant, the quintet dramatically illustrates a multiple galaxy collision, its powerful, ongoing interactions posed for a brief cosmic snapshot. On the sky, the quintet and NGC 7331 are separated by about half a degree. via NASA