Astronomy Archives

April 21, 2020April 21, 2020 by Matt Williams

Hubble Sees a Galaxy With Spiral Arms, Surrounded by Other Spiral Arms

Even after thirty years of faithful service, the Hubble Space Telescope continues to reveal truly fascinating things about our Universe. This includes the image (shown at top) taken of the astronomical feature known as NGC 2273, a barred spiral galaxy similar to the Milky Way. However, upon closer inspection, the image reveals that the spiral arms of this galaxy contain a second set of spiral arms.

April 21, 2020April 21, 2020 by Matt Williams

Interstellar Comet 2I/Borisov Formed in a Very Cold Environment

In the summer of 2019, a team of astronomers from NASA, the ESA, and the International Scientific Optical Network (ISON) announced the detection of the comet 2I/Borisov. This comet was the only second interstellar visitor observed passed through our Solar System, coming on the heels of the mysterious ‘Oumuamua. For this reason, astronomers from all over the world watched this comet intently as it made its closest pass to the Sun.

One such group, led by Martin Cordiner and Stefanie Milam of NASA’s Goddard Space Flight Center, observed 2I/Borisov using the ESO’s Atacama Large Millimeter/submillimeter Array (ALMA) in the Chilean Andes. This allowed them to observe the gases 2I/Borisov released as it moved closer to our Sun, thus providing the first-ever chemical composition readings of an interstellar object.

April 21, 2020April 21, 2020 by Evan Gough

Astronomers Watch a Nova Go From Start to Finish for the First Time

Artistic representation of a nova eruption: During a nova eruption a white dwarf sucks matter from its companion star and stores this mass on its surface until the gas pressure becomes extremely high. CREDIT © Nova_by K. Ulaczyk, Warschau Universität Observatorium

A nova is a dramatic episode in the life of a binary pair of stars. It’s an explosion of bright light that can last weeks or even months. And though they’re not exactly rare—there are about 10 each year in the Milky Way—astronomers have never watched one from start to finish.

Until now.

April 20, 2020April 20, 2020 by David Dickinson

Catching the Peak of the 2020 April Lyrids

Stuck at home with clear skies? We’re all in a similar situation, as the ongoing pandemic sees most of the worldwide amateur astronomy community observing from home or from their backyard. One astronomical sure-fire event coming up this week requires no special equipment, just a set of working ‘Mk-1 eyeballs’ and a clear sky: the April Lyrids.

April 18, 2020 by Matt Williams

Astronomers Might Have Imaged a Second Planet Around Nearby Proxima Centauri – and it Might Have a Huge Set of Rings

An artist's illustration of the Proxima Centauri system. Proxima b is on the left, while Proxima C is on the right. Image Credit: Lorenzo Santinelli

In 2016, astronomers working for the European Southern Observatory (ESO) confirmed the existence of a terrestrial planet around Earth’s closest stellar neighbor – Proxima Centauri. The discovery of this nearby extrasolar planet (Proxima b) caused no shortage of excitement because, in addition to being similar in size to Earth, it was found to orbit within the star’s habitable zone (HZ).

Thanks to an INAF-led team, a second exoplanet (a super-Earth) was found early this year around Proxima Centauri using the Radial Velocity Method. Based on the separation between the two planets, another INAF-led team attempted to observe this planet using the Direct Imaging Method. While not entirely successful, their observations raise the possibility that this planet has a system of rings around it, much like Saturn.

April 17, 2020April 17, 2020 by Paul M. Sutter

Gravity is tested down to a scale smaller than the thickness of a human hair

Gravity was the first force of nature to be realized, and in the centuries since we first cracked the code of that all-pervasive pulling power, scientists have continually come up with clever ways to test our understanding. And it’s no surprise why: the discovery of a new wrinkle in the gravitational force could open up vistas of new physics, and maybe even the nature of reality itself.

April 17, 2020April 25, 2020 by Matt Williams

An Earth-Sized World Orbiting in its Star’s Habitable Zone Was Found in Older Kepler Data

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle) — This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

To date, astronomers have confirmed the existence of 4,144 extrasolar planets in 3,074 systems, with a further 5,094 candidates awaiting confirmation. The majority of these planets were found by the Kepler Space Telescope, which spent nine years (between May of 2009 and February of 2018) monitoring distant stars for transit signals – where a planet passing in front of a star causes a dip in brightness.

And yet, even though it is now defunct, the data that Kepler accumulated over the years continues to lead to new discoveries. For instance, a transatlantic team of researchers recently found a signal in Kepler‘s archival data that eluded detection before. This signal indicates that there is a second planet orbiting Kepler-1649, an M-type red dwarf star located 302 light-years away.

April 16, 2020April 16, 2020 by Evan Gough

Astronomers Finally Think They Understand Where Interstellar Object Oumuamua Came From and How it Formed

Artist’s impression of the first interstellar asteroid/comet, "Oumuamua". This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawaii. Credit: ESO/M. Kornmesser

‘Oumuamua caused quite a stir when it visited our Solar System in 2017. It didn’t stay long, however, and when it was spotted with the Pan-STARRS telescope in Hawaii on October 19th, it was already leaving. But its appearance in our part of the Universe spawned a lot of conjecture on its nature and its origins.

April 16, 2020April 16, 2020 by Matt Williams

Light Behaves Really Strangely Around a Black Hole

Combining observations done with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. The black hole blows a huge bubble of hot gas, 1,000 light-years across or twice as large and tens of times more powerful than the other such microquasars. The stellar black hole belongs to a binary system as pictured in this artist's impression. Credit: ESO/L. Calçada — Artist's impression of a Star feeding a black hole. Credit: ESO/L. Calçada

Black holes are famous for being inescapable. Within the event horizon of these celestial objects, matter and even light enter and then disappear forever. However, beyond the event horizon, black holes are known to form accretion disks from which light can escape. In fact, this is how astronomers are able to confirm the presence of black holes and determine their properties (i.e. mass, spin rate, etc.)

However, according to a recent NASA-funded study led by researchers from the California Institute of Technology (Caltech), there is evidence that not all light emanating from a black hole’s disk simply escapes. According to their observations, some of the light escaping from the disk is pulled back in by the black hole’s gravity and reflected off the disk again. These observations confirm something astronomers have theorized for about forty years.

April 15, 2020April 15, 2020 by Evan Gough

Astronomers Measure the Wind Speed on a Brown Dwarf for the First Time. Spoiler: Insanely Fast

This artist's conception illustrates the brown dwarf named 2MASSJ22282889-431026, observed by NASA's Hubble and Spitzer space telescopes. Brown dwarfs are more massive and hotter than planets but lack the mass required to become stars. Image credit: NASA

In some ways, brown dwarfs are nature’s stellar oddballs. A lot of stars exhibit strange behaviour at different times in their evolution. But brown dwarfs aren’t even certain that they’re stars at all.

But that doesn’t mean astronomers don’t want to study and understand them.