Category: Astronomy

“Astronomers have detected a highly collimated, bipolar jet from the so-called Red Square Nebula (RSN) surrounding the B[e]-type star MWC 922. The newly discovered jet could reveal more insights into the nature of the RSN and its emission. The finding is detailed in a paper published January 24 on the arXiv pre-print repository.”

The Study: https://arxiv.org/abs/1901.08592

Read more at: https://phys.org/news/2019-02-highly-collimated-jet-red-square.html

Image:  The Red Square Nebula. Image credit: Peter Tuthill, Sydney University Physics Dept., and the Palomar and W.M. Keck observatories.

An international team of scientists led by Italy’s National Institute for Astrophysics (INAF) and involving physicists from the University of Bristol spent three years observing the exoplanetary system Kepler-107 via the Telescopio Nazionale Galileo in La Palma.

They gathered more than a hundred spectroscopic measurements of all four sub-Neptune mass planets in Kepler-107 – named after the NASA Kepler space telescope that discovered the exoplanetary system five years ago. Unlike Earth’s relation to the sun, the planets in the Kelper-107 system are much closer to each other and their host star (their equivalent of our sun). All of the planets have an orbital period of days as opposed to years.

It is not uncommon for the planet that is closest to the host star to be the densest due to heating and interaction with the host star which can cause atmosphere loss. However, as reported in Nature Astronomy, in the case of Kepler-107, the second planet, 107c, is denser than the first, 107b. So much so that 107c contains in its core an iron mass fraction at least twice as large as that of 107b, indicating that at some point, 107c had a head-on high-speed giant collision with a protoplanet of the same mass or more collisions with multiple planets of a lower mass. These impacts would have ripped off part of the rock and silicate mantle of Kepler-107c, suggesting that it is denser now than it was originally.”

Study: https://www.nature.com/articles/s41550-018-0684-9

Read more at: https://phys.org/news/2019-02-giant-impacts-interplanetary-collisions.html

Image: “One frame from the middle of a hydrodynamical simulation of a high-speed head-on collision between two 10 Earth-mass planets. The temperature range of the material is represented by four colours grey, orange, yellow and red, where grey is the coolest and red is the hottest. Such collisions eject a large amount of the silicate mantle material leaving a high-iron content, high-density remnant planet similar to the observed characteristics of Kepler-107c. Credit: Zoe Leinhardt and Thomas Denman, University of Bristol”

“The Milky Way galaxy’s disk of stars is anything but stable and flat. Instead, it becomes increasingly warped and twisted far away from the Milky Way’s center, according to astronomers from National Astronomical Observatories of Chinese Academy of Sciences (NAOC).

From a great distance, the galaxy would look like a thin disk of stars that orbit once every few hundred million years around its central region, where hundreds of billions of stars, together with a huge mass of dark matter, provide the gravitational ‘glue’ to hold it all together.

But the pull of gravity becomes weaker far away from the Milky Way’s inner regions. In the galaxy’s far outer disk, the hydrogen atoms making up most of the Milky Way’s gas disk are no longer confined to a thin plane, but they give the disk an S-like warped appearance.

“It is notoriously difficult to determine distances from the sun to parts of the Milky Way’s outer gas disk without having a clear idea of what that disk actually looks like,” says Dr. Chen Xiaodian, a researcher at NAOC and lead author of the article published in Nature Astronomy on Feb. 4.”

Read more at: https://phys.org/news/2019-02-milky-warped.html

“The composition of the universe—the elements that are the building blocks for every bit of matter—is ever-changing and ever-evolving, thanks to the lives and deaths of stars.

An outline of how those elements form as stars grow and explode and fade and merge is detailed in a review article published Jan. 31 is the journal Science.”

Read more at: https://phys.org/news/2019-02-universe.html

“A U.S.-German research team has simulated meteorite impacts in the lab and followed the resulting structural changes in two feldspar minerals with X-rays as they happened. The results of the experiments at DESY and at Argonne National Laboratory in the US show that structural changes can occur at very different pressures, depending on the compression rate. The findings, published in the 1 February issue of the scientific journal Earth and Planetary Science Letters (published online in advance), will aid other scientist to reconstruct the conditions leading to impact craters on Earth and other terrestrial planets.”

Read more at: https://phys.org/news/2019-02-simulating-meteorite-impacts-lab.html

“True north isn’t quite where it used to be.

Earth’s north magnetic pole has been drifting so fast in the last few decades that scientists that past estimates are no longer accurate enough for precise navigation. On Monday, they released an update of where true north really was, nearly a year ahead of schedule.”

Read more at: https://phys.org/news/2019-02-compass-magnetic-north-pole.html

“Using European Southern Observatory’s Very Large Telescope (VLT), astronomers have investigated the galaxy NGC 1365. The study, presented in a paper published January 18 on the arXiv.org pre-print server, reveals essential insights about star formation processes and gas flows in this galaxy.”

The study: https://arxiv.org/abs/1901.06241

Read more at: https://phys.org/news/2019-02-astronomers-star-formation-gas-galaxy.html#jCp