This photo shows the cosmic region known as Sh2-239 and LDN 155, where star formation activity has caused the mix of dust and colors in the nebulas visible here. The deep colors and dark clouds in this image resemble paintings by some of history’s greatest artists.
The region lies near the southern end of Taurus located on the border of the constellations of Taurus and Perseus more than 400 light-years away. A light-year is the distance light travels in one year, or about 6 trillion miles (10 trillion kilometers).
Astrophotographer Adam Block of the Mt. Lemmon SkyCenter at the University of Arizona was one of the first to capture the nebula in such detail. He took multiple exposures to collect enough light for an image that would otherwise not be evident to the eye.
Credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona
The Gliese system is back in the news again with 3 planets in the Goldilocks zone.
Scientists Discover System with Three Planets in Habitable Zone
A team of scientists recently confirmed six, and possibly seven, planets orbiting a star system a mere 22 light-years from Earth. More importantly, three of those planets are super-Earths, lying in the Goldilocks Zone where liquid water could exist, making them possible candidates for the presence of life. This is the first system found with a fully-packed habitable zone. The findings will be published in the journal Astronomy & Astrophysics on June 26.
Previous studies of the triple star system called Gliese 667C showed the star hosts three planets with one of them in the habitable zone. Now, a team of astronomers has reexamined the system by re-mining existing European Southern Observatory’s HARPS data and combining it with data collected from the W. M. Keck Observatory and the Magellan Telescope to find evidence for up to seven planets around the star. These planets orbit the third faintest star of a triple star system. The two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon.
While the HARPS data has been available since 2006, the team re-examined the data using a set of algorithms called HARPS-TERRA developed by the paper’s lead-author Guillem Anglada-Escudé of the University of Göttingen, and Paul Butler of the Carnegie Institute for Science.
Those new findings were then combined with more than 12 years of data collected on one of the world’s largest telescopes, Keck I, fitted with the successful planet-hunting instrument HIRES.
“We started observing GJ 667C from Keck Observatory way back in 2000, six years before the Swiss HARPS team started observing it,” said University of California, Santa Cruz, astronomer and team member Steve Vogt. “And though the HARPS team was able to hit the star with much higher cadence over the past 6 years, our early observations more than doubled the overall time base of the data set, enabling much stronger constraints to be placed on the planet solutions.” Vogt’s work at the Keck Observatory was funded by a grant from the National Science Foundation (NSF).
“These new results highlight how valuable it can be to re-analyze data in this way and combine results from different teams on different telescopes,” Anglada-Escudé said.
Three of these planets are confirmed to be super-Earths — planets more massive than Earth, but less massive than planets like Uranus or Neptune — that are within their star’s habitable zone, a thin shell around a star in which water may be present in liquid form if conditions are right. This is the first time that three such planets have been spotted orbiting in this zone in the same system.
“We knew that the star had three planets from previous studies, so we wanted to see whether there were any more,” said Mikko Tuomi of the University of Hertfordshire, who also led the team. “By adding some new observations and revisiting existing data we were able to confirm these three and confidently reveal several more. Finding three low-mass planets in the star’s habitable zone is very exciting!”
Co-author Rory Barnes of the University of Washington noted the discovery suggests habitable planets may be more numerous than previously thought. “The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star. Instead of looking at ten stars to look for a single potentially habitable planet, we now know we can look at just one star and have a high chance of finding several of them,” Barnes said.
“This discovery is really the start of a whole new era studying Earth-like planets which may have liquid water on the surface,” said Maria Womack, National Science Foundation program officer. “This is a result of more than a decade of hard work using the best tools to do cutting-edge science — just the kind of research NSF loves to be a part of.”
The study used measurements from the HARPS spectrograph (European Southern Observatory, Chile), Keck I-HIRES (W. M. Keck Observatory, Mauna Kea, Hawaii, USA), and the PFS (Las Campanas Observatory, Chile).
A new perspective might inspire people to view our planet with more care.
The envelopes of galaxies are the interface between galaxies and the rest of the Universe — and we’re just beginning to fully explore the processes at work within them.
Astronomers using the NASA/ESA Hubble Space Telescope have shown for the first time that bursts of star formation have a major impact far beyond the boundaries of their host galaxy. These energetic events can affect galactic gas at distances of up to twenty times greater than the visible size of the galaxy — altering how the galaxy evolves, and how matter and energy is spread throughout the Universe.
When galaxies form new stars, they sometimes do so in frantic episodes of activity known as starbursts. These events were commonplace in the early Universe, but are rarer in nearby galaxies.
During these bursts, hundreds of millions of stars are born, and their combined effect can drive a powerful wind that travels out of the galaxy. These winds were known to affect their host galaxy — but this new research now shows that they have a significantly greater effect than previously thought.
An international team of astronomers observed 20 nearby galaxies, some of which were known to be undergoing a starburst. They found that the winds accompanying these star formation processes were capable of ionising  gas up to 650 000 light-years from the galactic centre — around twenty times further out than the visible size of the galaxy. This is the first direct observational evidence of local starbursts impacting the bulk of the gas around their host galaxy, and has important consequences for how that galaxy continues to evolve and form stars.
“The extended material around galaxies is hard to study, as it’s so faint,” says team member Vivienne Wild of the University of St. Andrews. “But it’s important — these envelopes of cool gas hold vital clues about how galaxies grow, process mass and energy, and finally die. We’re exploring a new frontier in galaxy evolution!”
The team used the Cosmic Origins Spectrograph (COS) instrument  on the NASA/ESA Hubble Space Telescope to analyse light from a mixed sample of starburst and control galaxies. They were able to probe these faint envelopes by exploiting even more distant objects — quasars, the intensely luminous centres of distant galaxies powered by huge black holes. By analysing the light from these quasars after it passed through the foreground galaxies, the team could probe the galaxies themselves.