Cosmic lenses support finding on faster than expected expansion of the universe

By using galaxies as giant gravitational lenses, an international group of astronomers using the NASA/ESA Hubble Space Telescope have made an independent measurement of how fast the universe is expanding. The newly measured expansion rate for the local Universe is consistent with earlier findings. These are, however, in intriguing disagreement with measurements of the early universe. This hints at a fundamental problem at the very heart of our understanding of the cosmos. …

Read More...

Comments Off on Cosmic lenses support finding on faster than expected expansion of the universe

New space weather model helps simulate magnetic structure of solar storms

A new model is mapping out the path of coronal mass ejections as they travel from the sun to Earth, where these storms can interact with our planet’s magnetic fields and cause a variety of space weather effects. …

Read More...

Comments Off on New space weather model helps simulate magnetic structure of solar storms

A look at a rapidly spinning black hole! (Video)

How do stellar-mass black holes spin? This week we discuss this topic as new results from NASA’s NuSTAR spacecraft which looked at the black hole known as GS 1354−645. …

Read More...

Comments Off on A look at a rapidly spinning black hole! (Video)

Rapid gas flares discovered in white dwarf star for the first time

Incredibly rapid gas flares from a white dwarf binary star system have been detected for the first time by scientists. The first sighting of such activity, it suggests that our current understanding of star habits and their capabilities is incomplete. …

Read More...

Comments Off on Rapid gas flares discovered in white dwarf star for the first time

Proxima’s orbit around Alpha Centauri (Kervella et al.)

Vol. 598
In section 1. Letters

Proxima’s orbit around Alpha Centauri

by P. Kervella, F. Thévenin, C. Lovis, A&A 598, L7

alt

Alpha Centauri A and B, and Proxima Centauri are our closest stars. In addition, Proxima Centauri has recently been shown to host a small-mass planet in its so-called habitable zone. It is thus important to become better aquainted with these very close neighbours.
From statistical arguments, there could be little doubt that Proxima Centauri is gravitationally bound to the binary system formed by Alpha Centauri A and B. Kervella and Thévenin analyze high-precision radial velocity and astrometric data to show, with a high level of confidence, that it is the case. They also derive the orbit of Proxima which has a period of approximately 550,000 years, an eccentricity of 0.5 and a periastron of 4300 au. Planet (and comet) formation in this triple system should be investigated on the basis of these measurements.

Read More...

Comments Off on Proxima’s orbit around Alpha Centauri (Kervella et al.)

How to Get A Job in Astronomy

“How do I get a job in astronomy?” is probably the most asked question I get. Here’s some advice for those considering a career in astronomy, and it’s not all about getting a PhD. …

Read More...

Comments Off on How to Get A Job in Astronomy

Signs of life on Wolf 1061 exoplanet: One of the extrasolar systems closest to Earth

Is there anybody out there? The question of whether Earthlings are alone in the universe has puzzled everyone from biologists and physicists to philosophers and filmmakers. It’s also the driving force behind San Francisco State University astronomer Stephen Kane’s research into exoplanets — planets that exist outside Earth’s solar system. As one of the world’s leading “planet hunters,” Kane focuses on finding “habitable zones,” areas where water could exist in…

Read More…

#JWST Is Less than 2 Years Away! (Video)

Future in Space Hangout Sponsored by .SPACE Domains. Get your domain name for $2.99 by clicking on this link: https://goo.gl/e2b5HB …

Read More...

Comments Off on #JWST Is Less than 2 Years Away! (Video)

Huygens Probe on Titan; Cassini’s Final Year; Milky Way Ripping off Neighbors | SFN #190 (Video)

A look back at the touchdown of the Huygens lander on Titan some twelve years ago and a look ahead at what’s in store for the Cassini later this year; and astronomers find distant stars in the Milky Way were probably ripped off of another galaxy. …

Read More...

Comments Off on Huygens Probe on Titan; Cassini’s Final Year; Milky Way Ripping off Neighbors | SFN #190 (Video)

Comet Swarms or a Alien Megastructures? The Strange Variations of the Star KIC 8462852 (Video)

A star with unusual changes in brightness was discovered the Kepler Mission Planet Hunters. …

Read More...

Comments Off on Comet Swarms or a Alien Megastructures? The Strange Variations of the Star KIC 8462852 (Video)

Internal bow shocks in the IRAS 04166+2706 jet (Tafalla et al.)

Vol. 597
In section 6. Interstellar and circumstellar matter

Anatomy of the internal bow shocks in the IRAS 04166+2706 protostellar jet

by M. Tafalla, Y.-N. Su, H. Shang, D. Johnstone, Q. Zhang, J. Santiago-Garcia, C.-F. Lee, N. Hirano, and L.-Y. Wang A&A 597, A119

alt

Highly-collimated jets and wide-angle outflows are two related components of the mass-ejection activity that are associated with stellar birth. The authors use the ALMA interferometer to study the relation between the jet and the outflow in the IRAS 04166+2706 protostar, which drives a molecular jet that contains multiple emission peaks symmetrically located from the central source, as well as a wide-angle outflow consisting of two conical shells. They find that the emission peaks in the IRAS 04166+2706 jet likely represent internal bow shocks where material is being ejected laterally away from the jet axis. While the linear momentum of the ejected gas is dominated by the component in the jet direction, the sideways component is not negligible, and could potentially affect the distribution of gas in the surrounding outflow and core.

Read More...

Comments Off on Internal bow shocks in the IRAS 04166+2706 jet (Tafalla et al.)

Multi-epoch images and spectra of the components of Z CMa in the near-infrared during the 2008 outburst (Bonnefoy et al.)

Vol. 597
In section 7. Stellar structure and evolution

The 2008 outburst in the young stellar system Z CMa. III. Multi-epoch high-angular resolution images and spectra of the components in near-infrared

by M. Bonnefoy, G. Chauvin, C. Dougados, et al. A&A 597, A91

alt

Z CMa is a complex pre-main sequence binary with a current separation of 110 mas, known to consist of a FU Orionis star (SE component) and an embedded Herbig Be star (NW component). This paper presents a wealth of new observations, both imaging and spectroscopic, of each component of the Z CMa system during its most recent 2008-2009 outburst (as well as an extra observation once the system was back in its quiescent state). The authors confirm that the NW star dominates the system flux over the 1.1-3.8 mum range and is responsible for the photometric outburst. From extracted medium-resolution (R~2000-4000) near-infrared (1.1-2.4 mum) spectra of the individual components, the authors show that the SE component has a spectrum typical of FU Orionis objects, and that the NW component spectrum is characteristic of embedded out-bursting protostars and EX Or objects. The blueing of the continuum of the NW component along with the absolute flux and color-variation of the system during the outburst suggests that the outburst was caused by a complex interplay between (a) a variation of the extinction in the line of sight of the NW component, and (b) the emission of shocked regions close to the NW component.

Read More...

Comments Off on Multi-epoch images and spectra of the components of Z CMa in the near-infrared during the 2008 outburst (Bonnefoy et al.)