Posted on by Matt Williams

Not Saying it was Aliens, but ‘Oumuamua Probably Wasn’t a Nitrogen Iceberg…

Artist’s impression of the interstellar object, `Oumuamua, experiencing outgassing as it leaves our Solar System. Credit: ESA/Hubble, NASA, ESO, M. Kornmesser

On October 19th, 2017, astronomers made the first-ever detection of an interstellar object (ISO) passing through our Solar System. Designated 1I/2017 U1′ Oumuamua, this object confounded astronomers who could not determine if it was an interstellar comet or an asteroid. After four years and many theories (including the controversial “ET solar sail” hypothesis), the astronomical community appeared to land on an explanation that satisfied all the observations.

The “nitrogen iceberg” theory stated that ‘Oumuamua was likely debris from a Pluto-like planet in another solar system. In their latest study, titled “The Mass Budget Necessary to Explain ‘Oumuamua as a Nitrogen Iceberg,” Amir Siraj and Prof. Avi Loeb (who proposed the ET solar sail hypothesis) offered an official counter-argument to this theory. According to their new paper, there is an extreme shortage of exo-Plutos in the galaxy to explain the detection of a nitrogen iceberg.

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Posted on by Paul M. Sutter

Astronomy Jargon 101: Type-II Supernovae

This image of the supernova remnant SN 1987A was taken by the NASA/ESA Hubble Space Telescope in January 2017 using its Wide Field Camera 3 (WFC3). Since its launch in 1990 Hubble has observed the expanding dust cloud of SN 1987A several times has helped astronomers get a better understanding of these cosmic explosions. Supernova 1987A is located in the centre of the image amidst a backdrop of stars. The bright ring around the central region of the exploded star is material ejected by the star about 20 000 years before the actual explosion took place. The supernova is surrounded by gaseous clouds. The clouds’ red colour represents the glow of hydrogen gas. Image Credit: NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) and P. Challis (Harvard-Smithsonian Center for Astrophysics)
This image of the supernova remnant SN 1987A was taken by the NASA/ESA Hubble Space Telescope in January 2017 using its Wide Field Camera 3 (WFC3). Since its launch in 1990 Hubble has observed the expanding dust cloud of SN 1987A several times has helped astronomers get a better understanding of these cosmic explosions. Supernova 1987A is located in the centre of the image amidst a backdrop of stars. The bright ring around the central region of the exploded star is material ejected by the star about 20 000 years before the actual explosion took place. The supernova is surrounded by gaseous clouds. The clouds’ red colour represents the glow of hydrogen gas. Image Credit: NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) and P. Challis (Harvard-Smithsonian Center for Astrophysics)

In this series we are exploring the weird and wonderful world of astronomy jargon! You’ll have a blast learning about today’s topic: Type-II Supernovae!

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Posted on by Matt Williams

Astronomers Measure the Atmosphere on a Planet Hundreds of Light-Years Away

An artist's conception of the hot Jupiter WASP-79b. (Image credit: NASA)

The field of extrasolar planet research has advanced by leaps and bounds over the past fifteen years. To date, astronomers have relied on space-based and ground-based telescopes to confirm the existence of 4,566 exoplanets in 3,385 systems, with another 7,913 candidates awaiting confirmation. More importantly, in the past few years, the focus of exoplanet studies has slowly shifted from the process of discovery towards characterization.

In particular, astronomers are making great strides when it comes to the characterization of exoplanet atmospheres. Using the Gemini South Telescope (GST) in Chile, an international team led by Arizona State University (ASU) was able to characterize the atmosphere of a “hot Jupiter” located 340 light-years away. This makes them the first team to directly measure the chemical composition of a distant exoplanet’s atmosphere, a significant milestone in the hunt for habitable planets beyond our Solar System.

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Posted on by Matt Williams

Will Water Bears be the First Interstellar Astronauts?

In just a few years, astronauts will walk on the surface of the Moon for the first time since the Apollo Era. In addition to the Artemis Program, NASA’s fabled return to the Moon, there are also a number of planned missions involving the European Space Agency (ESA), JAXA, China, and Russia. By the 2030s, NASA and China hope to send crewed missions to Mars, which will culminate in the creation of a permanent base on the surface.

When it comes to interstellar missions, however, there are no plans for crewed missions on the table. While there are proposals for sending robotic missions, sending astronauts to nearby stars and exoplanets simply isn’t feasible yet. However, according to new research led by the University of California, interstellar missions could be conducted in the near future that would have tardigrades (aka. “Water Bears”) as their crew.

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Posted on by Brian Koberlein

Experiment Finds no Sign of Sterile Neutrinos

Could sterile neutrinos be a fourth kind of neutrino? Credit: IceCube - University of Wisconsin

We don’t know what dark matter is. We do know the characteristics of dark matter, and much of how it behaves, so we know what physical properties dark matter must have, but no known matter has all the necessary characteristics of dark matter. So we’re stumped.

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Posted on by Evan Gough

What’s Snuffing Out Galaxies Before Their Time?

The VERTICO—Virgo Environment Traced in Carbon Monoxide—Survey observed the gas reservoirs in 51 galaxies in the nearby Virgo Cluster and found that the extreme environment in the cluster was killing galaxies by robbing them of their star-forming fuel. In this composite image, ALMA’s radio wavelength observations of the VERTICO galaxies’ molecular gas disks are magnified by a factor of 20. They are overlaid on the X-ray image of the hot plasma within the Virgo Cluster. Credit: ALMA (ESO/NAOJ/NRAO)/S. Dagnello (NRAO)/Böhringer et al. (ROSAT All-Sky Survey)

In the Milky Way, the formation rate of stars is about one solar mass every year. About 10 billion years ago, it was ten solar masses every year. What happened?

Stars are born in giant molecular clouds (GMCs), and astronomers think that the environment in galaxies affects these clouds and their ability to spawn new stars. Sometimes the environment is so extreme that entire galaxies stop forming new stars.

Astronomers call this “quenching,” and they want to know what causes it.

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