Astronomy Archives

May 1, 2020May 1, 2020 by Evan Gough

Rocky Planets Orbiting White Dwarf Stars Could be the Perfect Places to Search for Life

Artist's rendition of a white dwarf from the surface of an orbiting exoplanet. Astronomers have found two giant planet candidates orbiting two white dwarfs. More proof that giant planets can surve their stars' red giant phases. Image Credit: Madden/Cornell University

Some very powerful telescopes will see first light in the near future. One of them is the long-awaited James Webb Space Telescope (JWST.) One of JWST’s roles—and the role of the other upcoming ‘scopes as well—is to look for biosignatures in the atmospheres of exoplanets. Now a new study is showing that finding those biosignatures on exoplanets that orbit white dwarf stars might give us our best chance to find them.

April 29, 2020April 29, 2020 by Matt Williams

You’re Looking at Spiral Galaxies, Already Forming When the Universe was Just a Baby

Credit: Michele Ginolfi (ALPINE collaboration); ALMA(ESO/NAOJ/NRAO); NASA/JPL-Caltech/R. Hurt (IPAC)

One of the most exciting developments in astronomy today is the way that advanced arrays and techniques are letting astronomers see farther back in time to the earliest periods of the Universe. In so doing, astronomers hope to get a closer at the earliest galaxies to learn more about how and when they first emerged – which can tell us a great deal more about their subsequent evolution.

This was the purpose of the ALMA Large Program to INvestigate C+ at Early times (ALPINE), a multiwavelength survey that examined galaxies that were around when the Universe was less than 1.5 billion years old. With funding provided by NASA and the European Southern Observatory (ESO), the ALPINE collaboration analyzed this data and learned some interesting things about the early evolution of galaxies.

April 28, 2020April 28, 2020 by Matt Williams

Fomalhaut’s Planet Has Gone Missing, But it Might Have Been Something Even More Interesting

Planets don’t simply disappear. And yet, that appears to be what happened to Fomalhaut b (aka. Dagon), an exoplanet candidate located 25 light-years from Earth. Observed for the first time by the Hubble Space Telescope in 2004, then confirmed by follow-up observations in 2008 and 2012, this exoplanet candidate was the first to be detected in visible wavelengths (i.e. the Direct Imaging Method.)

Over time, this candidate got fainter and wider until it disappeared from sight altogether. This led to all kinds of speculation, which included the possibility of a collision that reduced the planet to debris. Recently, a team of astronomers from the University of Arizona has suggested another possibility – Fomalhaut b was never a planet at all, but an expanding cloud of dust from two planetesimals that smashed together.

April 27, 2020April 27, 2020 by David Dickinson

Watch Asteroid 1998 OR2 Zip Past Earth This Week

A fascinating asteroid named 1998 OR2 pays our neck of the inner solar system a visit early Wednesday morning, and if skies are clear, you might just get a chance to watch it slide by.

April 25, 2020April 25, 2020 by Matt Williams

A Star is Orbiting the Milky Way’s Black Hole and Moving Exactly How Einstein Predicted it Should

Observations made with ESO’s Very Large Telescope (VLT) have revealed for the first time that a star orbiting the supermassive black hole at the centre of the Milky Way moves just as predicted by Einstein’s theory of general relativity. Its orbit is shaped like a rosette and not like an ellipse as predicted by Newton's theory of gravity. This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole. This artist’s impression illustrates the precession of the star’s orbit, with the effect exaggerated for easier visualisation.

At the center of our galaxy, roughly 26,000 light-years from Earth, is the Supermassive Black Hole (SMBH) known as Sagittarius A*. The powerful gravity of this object and the dense cluster of stars around it provide astronomers with a unique environment for testing physics under the most extreme conditions. In particular, it offers them a chance to test Einstein’s Theory of General Relativity (GR).

For example, in the past thirty years, astronomers have been observing a star in the vicinity of Sagittarius A* (S2) to see if its orbit conforms to what is predicted by General Relativity. Recent observations made with the ESO’s Very Large Telescope (VLT) have completed an observation campaign that confirmed that the star’s orbit is rosette-shaped, once again proving that Einstein theory was right on the money!

April 25, 2020April 25, 2020 by Matt Williams

This is the Final Picture NASA’s Spitzer Space Telescope

This view shows the California Nebula imaged in visible light. The inset shows a section of the nebula imaged by NASA's recently retired Spitzer Space Telescope, which studied the universe in infrared light. Credit: NASA/JPL-Caltech/ Palomar Digitized Sky Survey

On Jan. 30th, 2020, NASA’s Spitzer Space Telescope was retired after sixteen years of faithful service. As one of the four NASA Great Observatories – alongside Hubble, Chandra, and Compton space telescopes – Spitzer was dedicated to studying the Universe in infrared light. In so doing, it provided new insights into our Universe and enabled the study of objects and phenomena that would otherwise be impossible.

For instance, Spitzer was the first telescope to see light from an exoplanet and made important discoveries about comets, stars, and distant galaxies. It is therefore fitting that mission scientists decided to spend the last five days before the telescope was to be decommissioned capturing breathtaking images of the California Nebula, which were stitched into a mosaic and recently released to the public.

April 24, 2020April 24, 2020 by Matt Williams

Astronomers Find a Six-Planet System Which Orbit in Lockstep With Each Other

Artist's concept of the TRAPPIST-1 star system, an ultra-cool dwarf that has seven Earth-size planets orbiting it. We're going to keep finding more and more solar systemsl like this, but we need observatories like WFIRST, with starshades, to understand the planets better. Credits: NASA/JPL-Caltech

To date, astronomers have confirmed the existence of 4,152 extrasolar planets in 3,077 star systems. While the majority of these discoveries involved a single planet, several hundred star systems were found to be multi-planetary. Systems that contain six planets or more, however, appear to be rarer, with only a dozen or so cases discovered so far.

This is what astronomers found after observing HD 158259, a Sun-like star located about 88 light-years from Earth, for the past seven years using the SOPHIE spectrograph. Combined with new data from the Transiting Exoplanet Space Satellite (TESS), an international team reported the discovery of a six planet system where all were in near-perfect rhythm with each other.

April 22, 2020April 22, 2020 by Matt Williams

Astronomers Detected a Black Hole Merger With Very Different Mass Objects

Still image from a numerical simulation of an unequal mass binary black hole merger, with parameters consistent with GW190412. [Image credit: N. Fischer, H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), Simulating eXtreme Spacetimes project]

In another first, scientists at the LIGO and Virgo gravitational wave detectors announced a signal unlike anything they’ve ever seen before. While many black hole mergers have been detected thanks to LIGO and Virgo’s international network for detectors, this particular signal (GW190412) was the first where the two black holes had distinctly different masses.

April 22, 2020April 22, 2020 by Evan Gough

Super-Supernova Released Ten Times More Energy than a Regular Supernova

Artist's conception of SN2016aps, a candidate pulsational pair instability supernova. The explosion energy of SN2016aps, fueled by the shedding of a massive shell of gas, was ten times that of a normal-sized supernova, making SN2016aps the most massive supernova ever identified. Credit: M. Weiss

It’s easy to run out of superlatives and adjectives when your puny human language is trying to describe humongously-energetic events in the Universe. So now it’s down to this: a really powerful supernova is a “super-supernova.”

But whatever name we give it, it’s a monster. A monsternova.

April 22, 2020April 21, 2020 by Paul M. Sutter

BepiColombo captured images of Earth during its recent flyby

Farewell! Even though the BepiColombo mission launched for Mercury in 2018, it’s still hanging around the Earth – at least, briefly, as shown in this stunning image recently released by the European Space Agency.

In the image, the Earth hangs serenely in between BepiColumbo’s magnetometer boom (on the right) and its medium-gain antenna (on the left).

But the Earth flyby wasn’t without its tense moments. The spacecraft relies on solar power, and during the loop around Earth it had to spend some time in our planet’s shadow – and out of the sun. To prepare, the mission scientists made sure that BepiColombo was fully charged and nice and warm before the maneuver.

And on April 10, the date of the flyby, it all went swimmingly.

The spacecraft is on a long, winding journey sunwards towards the smallest planet in the solar system, making loop after loop first around Earth, then Venus a couple times, then Mercury itself half a dozen times before parking itself in orbit. The frequent loops are necessary because at launch BepiColombo was traveling at the same speed as the Earth in its orbit (29.78 km/s), and needs to match that of Mercury (47.36 km/s), and it does so by borrowing some energy from the planets themselves.

Once BepiColombo reaches Mercury, it will separate into two individual probes: the Mercury Planetary Orbiter and the Mercury Magnetospheric Orbiter. The twin orbiters will attempt to answer several challenging riddles about the planet nearest to the sun, like the origins of Mercury’s faint-but-still-there magnetic field and atmosphere, and the craters pitting its surface.

But it will take a long time to get there. BepiColombo’s final arrival at Mercury isn’t scheduled until December of 2025, showing how reaching the inner planets of our system can be sometimes more difficult than journeys outward – it turns out that doing planetary dances is more challenging than you might think.