A New Bound on Axionssu201802 | www.cfa.harvard.edu/
https://www.cfa.harvard.edu/news/su201802

CfA astronomer Paul Nulsen and his colleagues used a novel method to investigate the nature of axions. Quantum mechanics constrain axions, if they exist, to interact with light in the presence of a magnetic field.
As they propagate along a strong field, axions and photons should transmute from one to the other other in an oscillatory manner. Because the strength of any possible effect depends in part on the energy of the photons,
the astronomers used the Chandra X-ray Observatory to monitor bright X-ray emission from galaxies. They observed X-rays from the nucleus of the galaxy M87, which is known to have strong magnetic fields, and which (at
a distance of only fifty-three million light-years) is close enough to enable precise measurements of variations in the X-ray flux. Moreover, M87 lies in a cluster of galaxies, the Virgo cluster, which should insure
the magnetic fields extend over very large scales and also facilitate the interpretation. Not least, M87 has been carefully studied for decades and its properties are relatively well known.

The search did not find the signature of axions. It does, however, set an important new limit on the strength of the coupling between axions and photons, and is able to rule out a substantial fraction of the possible
future experiments that might be undertaken to detect axions. The scientists note that their research highlights the power of X-ray astronomy to probe some basic issues in particle physics, and point to complementary
research activities that can be undertaken on other bright X-ray emitting galaxies.

Update on an Interstellar Asteroid
http://aasnova.org/2018/01/19/update-on-an-interstellar-asteroid/

Are we sure ‘Oumuamua didn’t originate in our solar system and get scattered into a weird orbit? Jason Wright (The Pennsylvania State University)
demonstrates via a series of calculations that no known solar system body could have scattered ‘Oumuamua onto its current orbit — nor could any as
yet unknown object bound to our solar system.

Eric Mamajek (Caltech and University of Rochester) shows that the kinematics of ‘Oumuamua are consistent with what we might expect of interstellar
field objects, though he argues that its kinematics suggest it’s unlikely to have originated from many of the nearest stellar systems.

https://www.nasa.gov/feature/jpl/asteroid-2002-aj129-to-fly-safely-past-earth-february-4

Asteroid 2002 AJ129 will make a close approach to Earth on Feb. 4, 2018 at 1:30 p.m. PST (4:30 p.m. EST / 21:30 UTC). At the time of closest approach,
the asteroid will be no closer than 10 times the distance between Earth and the Moon (about 2.6 million miles, or 4.2 million kilometers).

2002 AJ129 is an intermediate-sized near-Earth asteroid, somewhere between 0.3 miles (0.5 kilometers) and 0.75 miles (1.2 kilometers) across. It was discovered
on Jan. 15, 2002, by the former NASA-sponsored Near Earth Asteroid Tracking project at the Maui Space Surveillance Site on Haleakala, Hawaii. The asteroid’s
velocity at the time of closest approach, 76,000 mph (34 kilometers per second), is higher than the majority of near-Earth objects during an Earth flyby.
The high flyby velocity is a result of the asteroid’s orbit, which approaches very close to the Sun -- 11 million miles (18 million kilometers). Although asteroid
2002 AJ129 is categorized as a Potentially Hazardous Asteroid (PHA), it does not pose an actual threat of colliding with our planet for the foreseeable future.

Comet Discoverer Thomas Bopp (1949–2018) - Sky & Telescope
http://www.skyandtelescope.com/astronomy-news/people-places-and-events/thomas-bopp-1949-2018/

An unassuming amateur astronomer forever linked to one of the greatest comets in modern history has passed away.

Thomas Joel Bopp, the co-discoverer of Comet Hale-Bopp, died January 5, 2018, in Phoenix, Arizona, from liver cancer. He was 68 years old.

If you live in the western part of North America, Alaska, and the Hawaiian islands,
you might set your alarm early the morning of Wednesday, Jan. 31 for a lunar trifecta: a pre-dawn “super blue blood moon.”

https://www.nasa.gov/feature/super-blue-blood-moon-coming-jan-31

https://www.nasa.gov/...goddard/2018/nasa-team-studies-middle-aged-sun-by-tracking-motion-of-mercury

Like the waistband of a couch potato in midlife, the orbits of planets in our solar system are expanding. It happens because the Sun’s gravitational grip gradually weakens as
our star ages and loses mass. Now, a team of NASA and MIT scientists has indirectly measured this mass loss and other solar parameters by looking at changes in Mercury’s orbit.

The new values improve upon earlier predictions by reducing the amount of uncertainty. That’s especially important for the rate of solar mass loss, because it’s related to
the stability of G, the gravitational constant. Although G is considered a fixed number, whether it’s really constant is still a fundamental question in physics.

https://www.forbes.com/...interstellar-visitor-oumuamua-was-shaped-by-cosmic-particles/#13fcfd497422

Last year, the interstellar interloper ʻOumuamua passed through the inner Solar System. Originally thought to be a comet, then later an asteroid, this visitor turned out to have properties
unlike any object ever seen before. It moved far too quickly and from too inclined an angle to originate from within our Solar System; neither Jupiter nor Neptune nor an Oort cloud object
could have flung it inwards with those properties. When we examined it in detail, it appeared to have a carbon-based coating over an icy interior, yet sprouted no tail, despite reaching
temperatures of 550 °F (290 °C). Oddest of all, it was cigar-shaped, approximately eight times as long as it was wide. While many origin theories have been proposed, an incredibly simple
possibility may provide all the answers: simply traveling through the Milky Way for billions of years may have transformed it into the object we see today.

Zooming into the galaxy cluster A1758N
https://www.youtube.com/watch?v=wh3oqUP7w-s


North, east, south, west: The many faces of Abell 1758 | ESA/Hubble
http://www.spacetelescope.org/news/heic1801/

Resembling a swarm of flickering fireflies, this beautiful galaxy cluster glows intensely in the dark cosmos, accompanied by the myriad bright lights of
foreground stars and swirling spiral galaxies. A1758N is a sub-cluster of Abell 1758, a massive cluster containing hundreds of galaxies. Although it may
appear serene in this NASA/ESA Hubble Space Telescope image, the sub-cluster actually comprises two even smaller structures currently in the turbulent
process of merging.

https://carnegiescience.edu/node/2288

New work from a team of Carnegie cosmochemists published by Science Advances reports analyses of carbon-rich dust grains
extracted from meteorites that show that these grains formed in the outflows from one or more type II supernovae more than
two years after the progenitor stars exploded. This dust was then blown into space to be eventually incorporated into new
stellar systems, including in this case, our own.

Meteorites Brought Water To Earth During the First Two Million Years - Astrobiology Magazine
https://www.astrobio.net/...ve/meteorites-brought-water-to-earth-during-the-first-two-million-years/

A new study of a rare basaltic meteorites called angrites suggests that volatiles, which are elements with relatively low boiling
points such as water, could have been brought to our planet by meteorites during the first two million years of the Solar System.

Since elements such as water and carbon are essential ingredients to life on Earth, researchers are keen to know when they arrived
on our planet.

https://aktuelles.uni-frankfurt.de/englisch/how-massive-can-neutron-stars-be/

The density of neutron stars is enormous, as if the entire Himalayas were compressed into a beer mug. However, there are
indications that a neutron star with a maximum mass would collapse to a black hole if even just a single neutron were added.

Together with his students Elias Most and Lukas Weih, Professor Luciano Rezzolla, physicist, senior fellow at the Frankfurt
Institute for Advanced Studies (FIAS) and professor of Theoretical Astrophysics at Goethe University Frankfurt, has now solved
the problem that had remained unanswered for 40 years: With an accuracy of a few percent, the maximum mass of non-rotating
neutron stars cannot exceed 2.16 solar masses.