Not All Black Holes are Ravenous Gluttons

This artist’s impression shows the record-breaking quasar J059-4351, the bright core of a distant galaxy that is powered by a supermassive black hole. The light comes from gas and dust that's heated up before it's drawn into the black hole. Credit: ESO/M. Kornmesser

Some Supermassive Black Holes (SMBHs) consume vast quantities of gas and dust, triggering brilliant light shows that can outshine an entire galaxy. But others are much more sedate, emitting faint but steady light from their home in the heart of their galaxy.

Observations from the now-retired Spitzer Space Telescope help show why that is.

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New Photos Show Jupiter’s Tiny Moon Amalthea

Juppy
Jupiter (and tiny Amalthea, crossing the Great Red Spot) as seen from Juno). Credit: NASA/JPL-Caltech/SwRI/MSSS. Image processing: Gerald Eichstädt

NASA’s Juno spacecraft spies a tiny inner moon of Jupiter, Amalthea.

It’s tiny, but it’s there. By now, we’re all used to seeing amazing photos of Jupiter courtesy of NASA’s Juno mission on a routine basis. Many of these are processed by volunteer ‘citizen scientists,’ and they show the swirling cloud-tops of Jove courtesy of the spacecraft’s JunoCam in stunning detail.

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A Star Became 1,000 Times Brighter, and Now Astronomers Know Why

Artist’s impression of one of the two stars in the FU Orionis binary system, surrounded by an accreting disk of material. What has caused this star — and others like it — to dramatically brighten? [NASA/JPL-Caltech]
Artist’s impression of one of the two stars in the FU Orionis binary system, surrounded by an accreting disk of material. Credit: NASA/JPL-Caltech

Astronomers were surprised in 1937 when a star in a binary pair suddenly brightened by 1,000 times. The pair is called FU Orionis (FU Ori), and it’s in the constellation Orion. The sudden and extreme variability of one of the stars has resisted a complete explanation, and since then, FU Orionis has become the name for other stars that exhibit similar powerful variability.

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White Dwarfs are Often Polluted With Heavier Elements. Now We Know Why

In this artist's illustration, lumps of debris from a disrupted planetesimal are irregularly spaced on a long and eccentric orbit around a white dwarf. Credit: Dr Mark Garlick/The University of Warwick

When stars exhaust their hydrogen fuel at the end of their main sequence phase, they undergo core collapse and shed their outer layers in a supernova. Whereas particularly massive stars will collapse and become black holes, stars comparable to our Sun become stellar remnants known as “white dwarfs.” These “dead stars” are extremely compact and dense, having mass comparable to a star but concentrated in a volume about the size of a planet. Despite being prevalent in our galaxy, the chemical makeup of these stellar remnants has puzzled astronomers for years.

For instance, white dwarfs consume nearby objects like comets and planetesimals, causing them to become “polluted” by trace metals and other elements. While this process is not yet well understood, it could be the key to unraveling the metal content and composition (aka. metallicity) of white dwarf stars, potentially leading to discoveries about their dynamics. In a recent paper, a team from the University of Colorado Boulder theorized that the reason white dwarf stars consume neighboring planetesimals could have to do with their formation.

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Do Clashing Galaxies Create Odd Radio Circles?

This multiwavelength image of the Cloverleaf ORC (odd radio circle) combines visible light observations from the DESI (Dark Energy Spectroscopic Instrument) Legacy Survey in white and yellow, X-rays from XMM-Newton in blue, and radio from ASKAP (the Australian Square Kilometer Array Pathfinder) in red. X. Zhang and M. Kluge (MPE), B. Koribalski (CSIRO)

Within the last five years, astronomers have discovered a new type of astronomical phenomenon that exists on vast scales – larger than whole galaxies. They’re called ORCs (odd radio circles), and they look like giant rings of radio waves expanding outwards like a shockwave. Until now, ORCs had never been observed in any wavelength other than radio, but according to a new paper released on April 30 2024, astronomers have captured X-rays associated with an ORC for the first time.

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Why Hot Jupiters Spiral into Their Stars

Illustration showing one of the darkest known exoplanets - a hot Jupiter as black as fresh asphalt - orbiting a star like our Sun. The day side of the planet, called WASP-12b, eats light rather than reflects it into space. Something is pulling this planet into its star. Credit: NASA, ESA, and G. Bacon (STScI)
Illustration showing one of the darkest known exoplanets - a hot Jupiter as black as fresh asphalt - orbiting a star like our Sun. The day side of the planet, called WASP-12b, eats light rather than reflects it into space. Something is pulling this planet into its star. Credit: NASA, ESA, and G. Bacon (STScI)

Exoplanets are a fascinating astronomy topic, especially the so-called “Hot Jupiters”. They’re overheated massive worlds often found orbiting very close to their stars—hence the name. Extreme gravitational interactions can tug them right into their stars over millions of years. However, some hot Jupiters appear to be spiraling in faster than gravity can explain.

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Astronomers are on the Hunt for Dyson Spheres

Artist's impression of a Dyson Sphere. The construction of such a massive engineering structure would create a technosignature that could be detected by humanity. Credit: SentientDevelopments.com/Eburacum45
Artist's impression of a Dyson Sphere. The construction of such a massive engineering structure would create a technosignature that could be detected by humanity. Credit: SentientDevelopments.com/Eburacum45

There’s something poetic about humanity’s attempt to detect other civilizations somewhere in the Milky Way’s expanse. There’s also something futile about it. But we’re not going to stop. There’s little doubt about that.

One group of scientists thinks that we may already have detected technosignatures from a technological civilization’s Dyson Spheres, but the detection is hidden in our vast troves of astronomical data.

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We Need to Consider Conservation Efforts on Mars

Curiosity at work firing a laser on Mars. This artist's concept depicts the rover Curiosity, of NASA's Mars Science Laboratory mission, as it uses its Chemistry and Camera (ChemCam) instrument to investigate the composition of a rock surface. ChemCam fires laser pulses at a target and views the resulting spark with a telescope and spectrometers to identify chemical elements. The laser is actually in an invisible infrared wavelength, but is shown here as visible red light for purposes of illustration. Credit: NASA

Astrobiology is the field of science that studies the origins, evolution, distribution, and future of life in the Universe. In practice, this means sending robotic missions beyond Earth to analyze the atmospheres, surfaces, and chemistry of extraterrestrial worlds. At present, all of our astrobiology missions are focused on Mars, as it is considered the most Earth-like environment beyond our planet. While several missions will be destined for the outer Solar System to investigate “Ocean Worlds” for evidence of life (Europa, Ganymede, Titan, and Enceladus), our efforts to find life beyond Earth will remain predominantly on Mars.

If and when these efforts succeed, it will have drastic implications for future missions to Mars. Not only will great care need to be taken to protect Martian life from contamination by Earth organisms, but precautions must be taken to prevent the same from happening to Earth (aka. Planetary Protection). In a recent study, a team from the University of New South Wales (UNSW) in Sydney, Australia, recommends that legal or normative frameworks be adopted now to ensure that future missions do not threaten sites where evidence of life (past or present) might be found.

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A Nebula that Extends its Hand into Space

This cloudy, ominous structure is CG 4, a cometary globule nicknamed ‘God’s Hand’. CG 4 is one of many cometary globules present within the Milky Way, and how these objects get their distinct form is still a matter of debate among astronomers. Image Credit: CTIO/NOIRLab/DOE/NSF/AURA Image Processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab)

The Gum Nebula is an emission nebula almost 1400 light-years away. It’s home to an object known as “God’s Hand” among the faithful. The rest of us call it CG 4.

Many objects in space take on fascinating, ethereal shapes straight out of someone’s psychedelic fantasy. CG4 is definitely ethereal and extraordinary, but it’s also a little more prosaic. It looks like a hand extending into space.

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China is Going Back to the Moon Again With Chang'e-6

China's Chang'e-6 mission launches from the Wenchang Spacecraft Launch Site. Credit: CGTN

On Friday, May 3rd, the sixth mission in the Chinese Lunar Exploration Program (Chang’e-6) launched from the Wenchang Spacecraft Launch Site in southern China. Shortly after, China announced that the spacecraft separated successfully from its Long March 5 Y8 rocket. The mission, consisting of an orbiter and lander element, is now on its way to the Moon and will arrive there in a few weeks. By June, the lander element will touch down on the far side of the Moon, where it will gather about 2 kg (4.4 lbs) of rock and soil samples for return to Earth.

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