Not just orbiting, but very closely orbiting, only about 2.5 Earth-Moon distances or about 961,000 km / 598,000 miles according to astronomical research coming out of Michigan State University.
The MSU press release:
Astronomers have found evidence for a star that whips around a black hole about twice an hour. This may be the tightest orbital dance ever witnessed for a black hole and a companion star.
Michigan State University scientists were part of the team that made this discovery, which used NASA’s Chandra X-ray Observatory as well as NASA’s NuSTAR and the Australia Telescope Compact Array.
The close-in stellar couple – known as a binary – is located in the globular cluster 47 Tucanae, a dense cluster of stars in our galaxy about 14,800 light years away from Earth.
While astronomers have observed this binary for many years, it wasn’t until 2015 that radio observations revealed the pair likely contains a black hole pulling material from a companion star called a white dwarf, a low-mass star that has exhausted most or all of its nuclear fuel.
New Chandra data of this system, known as X9, show that it changes in X-ray brightness in the same manner every 28 minutes, which is likely the length of time it takes the companion star to make one complete orbit around the black hole. Chandra data also shows evidence for large amounts of oxygen in the system a characteristic of white dwarfs. A strong case can, therefore, be made that that the companion star is a white dwarf, which would then be orbiting the black hole at only about 2.5 times the separation between the Earth and the moon.
Here is a description from Zooniverse I got in an email:
In this project you’ll be searching through images from NASA’s Wide-field Infrared Survey Explorer (WISE) mission, hunting for objects such as brown dwarfs and low-mass stars in our Solar System’s neighbourhood. You may find an object closer than Proxima Centauri (the closest star to the Sun) or even discover the Sun’s hypothesized ninth planet, which models suggest might appear in these images!
If you thought the outer atmospheres of the giant planets: Jupiter, Saturn, Uranus, and Neptune are cold think again. You are not unfounded, models suggest a temperature of -73 C would exist, but Voyager found temperatures of + 700 C (1000 K)!
We now know the atmosphere of Uranus has changed from 750 K to 550 K in 20 years and since the year 2013 the temperature as rebounded by 50 kelvin per year.
About the image:
ALMA/Hubble composite image of the gravitationally lensed galaxy SDP.81. The bright orange central region of the ring (ALMA’s highest resolution observation ever) reveals the glowing dust in this distant galaxy. The surrounding lower-resolution portions of the ring trace the millimeter wavelength light emitted by carbon monoxide. The diffuse blue element at the center of the ring is from the intervening lensing galaxy, as seen with the Hubble Space Telescope. Credit: ALMA (NRAO/ESO/NAOJ); B. Saxton NRAO/AUI/NSF; NASA/ESA Hubble, T. Hunter (NRAO)
From the NRAO press release:
Astronomers have discovered that a distant galaxy — seen from Earth with the aid of a gravitational lens — appears like a cosmic ring, thanks to the highest resolution images ever taken with the Atacama Large Millimeter/submillimeter Array (ALMA).
Forged by the chance alignment of two distant galaxies, this striking ring-like structure is a rare and peculiar manifestation of gravitational lensing as predicted by Albert Einstein in his theory of general relativity.
Gravitational lensing occurs when a massive galaxy or cluster of galaxies bends the light emitted from a more distant galaxy, forming a highly magnified, though much distorted image. In this particular case, the galaxy known as SDP.81 (its formal name is HATLAS J090311.6+003906) and an intervening galaxy line up so perfectly that the light from the more distant one forms a nearly complete circle as seen from Earth.
Discovered by the Herschel Space Observatory, SDP.81 is an active star-forming galaxy nearly 12 billion light-years away, seen at a time when the Universe was only 15 percent of its current age. It is being lensed by a massive foreground galaxy that is a comparatively nearby 4 billion light-years away.
“Gravitational lensing is used in astronomy to study the very distant, very early Universe because it gives even our best telescopes an impressive boost in power,” said ALMA Deputy Program Scientist Catherine Vlahakis. “With the astounding level of detail in these new ALMA images, astronomers will now be able to reassemble the information contained in the distorted image we see as a ring and produce a reconstruction of the true image of the distant galaxy.”
Most of us are familiar with the ice caps on Mars. Now research is pointing to glaciers on the Red Planet.
Researchers at the Niels Bohr Institute used radar observations and ice flow modeling to show the shape of the glaciers which occur in both hemispheres just below the surface.
It is not known if the glaciers are made of frozen water (H2O) or carbon dioxide (CO2) or even if it mud.
“We have looked at radar measurements spanning ten years back in time to see how thick the ice is and how it behaves. A glacier is after all a big chunk of ice and it flows and gets a form that tells us something about how soft it is. We then compared this with how glaciers on Earth behave and from that we have been able to make models for the ice flow,” explains Nanna Bjørnholt Karlsson, a postdoc at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.
The researchers calculate the volume of the glaciers could be equivalent to the amount needed to cover the entire planet with 1.1 meters if ice!
This is a huge discovery if it turns out to be accurate. Read the details at the Niels Bohr Institute.
The image depicts the glacial regions as blue dots. Image Credit: Mars Digital Image Model, NASA/Nanna Karlsson