Nova galáxia descoberta

http://sci.esa.int/hubble/61075-hubble-fortuitously-discovers-a-new-galaxy-in-the-cosmic-neighbourhood-heic1903/

Citando:
"An international team of astronomers recently used the NASA/ESA Hubble Space Telescope to study white dwarf stars within the globular cluster NGC 6752. The aim of their observations was to use these stars to measure the age of the globular cluster, but in the process they made an unexpected discovery.

Bedin I in NGC 6752. Credit: ESA/Hubble, NASA, Bedin et al., Digitized Sky Survey 2, CC BY 4.0

In the outer fringes of the area observed with Hubble's Advanced Camera for Surveys a compact collection of stars was visible. After a careful analysis of their brightnesses and temperatures, the astronomers concluded that these stars did not belong to the cluster – which is part of the Milky Way – but rather they are millions of light-years more distant.

Our newly discovered cosmic neighbour, nicknamed Bedin I by the astronomers, is a modestly sized, elongated galaxy. It measures only around 3000 light-years at its greatest extent – a fraction of the size of the Milky Way. Not only is it tiny, but it is also incredibly faint. These properties led astronomers to classify it as a dwarf spheroidal galaxy."

Andromeda mais pequena do que se pensava

http://www.astronomy.com/news/magazine/2018/02/adromeda-is-the-same-size-as-the-milky-way

Citando:
"Both the Milky Way and the Andromeda galaxy (M31) are giant spiral galaxies in our local universe. And in about 4 billion years, the Milky Way and Andromeda will collide in a gravitational sumo match that will ultimately bind them forever. 

Because astronomers previously thought that Andromeda was up to three times as massive as the Milky Way, they expected that our galaxy would be easily overpowered and absorbed into our larger neighbor. But now, new research suggests we’ve overestimated our opponent. 

In a study published today in the Monthly Notices of the Royal Astronomical Society, a team of Australian astronomers announced that Andromeda is not actually the heavyweight we once thought it was. Instead, they found that our nearest galactic neighbor is more or less the same mass as the Milky Way — some 800 billion times the mass of the Sun. 

To determine the heft of the Andromeda galaxy, the team used a technique that calculates the speed required for a quick-moving star to escape the gravitational pull of its host galaxy. This required speed needed for ejection is known as an object’s escape velocity. 

“When a rocket is launched into space, it is thrown out with a speed of [6.8 miles per second (11 kilometers per second)] to overcome the Earth’s gravitational pull,” said Prajwal Kafle, an astrophysicist from the University of Western Australia branch of the International Centre for Radio Astronomy Research, in a press release. “Our home galaxy, the Milky Way, is over a trillion times heavier than our tiny planet Earth, so to escape its gravitational pull, we have to launch with a speed of [342 miles per second (550 kilometers per second)]. We used this technique to tie down the mass of Andromeda.” 

This is not the first time a galaxy’s weight has been recalculated based on analyzing the escape velocities of objects within it. In 2014, Kafle used a similar technique to revise down the mass of the Milky Way, showing that our galaxy has much less dark matter — a mysterious form of matter that has gravity but does not interact with light — than previously thought."

Andrómeda comeu o pequeno almoço.

E o jantar será a Via Láctea:
https://www.theguardian.com/science/2018/jul/23/discovered-milky-way-long-lost-galactic-sibling

Citando:
"The theory is backed up by a massive stream of stars trailing out behind Andromeda, which the scientists believe can be tracked back to this event. And it could help explain M32’s unusual composition, which has remained a source of puzzlement until now.

“M32 is a weirdo,” Bell said. “While it looks like a compact example of an old, elliptical galaxy, it actually has lots of young stars. It’s one of the most compact galaxies in the universe.”"

Somos feitos de estrelas...

Mas aparentemente de outra galáxia:
https%3A%2F%2Fwww.mnn.com%2Fearth-matters%2Fspace%2Fstories%2Fatoms-human-body-galaxy#pt0-932462

Galáxia NGC 1055 e o ESO

http://www.mirror.co.uk/news/uk-news/milky-ways-massive-sister-constellation-9952111

Fonte de sinais de rádio descoberta (FRB)

Mais um FRB (radio bursts) detectado, e atribuído a uma galáxia que está... Longinho:
http://www.bbc.com/news/science-environment-38502607


Citando:
"The first FRB was discovered in 2007, in archived data from the Parkes Radio Telescope in Australia. Astronomers were searching for new examples of magnetised neutron stars called pulsars, but found a new phenomenon - a radio burst from 2001. Since then, 18 FRBs - also referred to as "flashes" or "sizzles" - have been found in total."
(...)
"Unlike all the others, this FRB - discovered in 2012 - has recurred several times.
"When we reported last year that one of these objects was repeating, that - in one go - knocked out about half of those models, because for this one source, at least, we knew it couldn't be explosive. It had to be something where the engine that produced this survived for the next flash."
In 83 hours of observing time over six months in 2016, the VLA detected nine bursts from FRB 121102."

Galáxia de ripo raro (Hoag's Object)

http://www.theregister.co.uk/2017/01/04/rare_ring_shaped_galaxy_discovered/
Citando:
"A rarer-than-rare galaxy 359 million light years away from Earth has been spotted by physicists.
Designated PGC 1000714 [paywalled], the galaxy is a ring-shape system orbiting a cooler centre without any connection between the two – a formation referred to as Hoag's Object.