Stars get official names


WHAT’S IN A NAME? Names of eight stars in the constellation Orion, plus one (Cursa) in Eridanus, are among the 227 now officially sanctioned by the International Astronomical Union. Picture by Rogelio Bernal Andreo

From Science News:

Gaggle of stars get official names

International Astronomical Union weighs in with formal designations for 227 stars

By Christopher Crockett

1:47pm, December 2, 2016

For centuries, stargazers have known which star was Polaris and which was Sirius, but those designations were by unofficial tradition. The International Astronomical Union, arbiter of naming things in space, has now blessed the monikers of 227 stars in our galaxy. As of November 24, names such as Polaris (the North Star) and Betelgeuse (the bright red star in Orion) are approved.

Until now, there has been no central star registry or guidelines for naming. There are many star catalogs, each one designating stars with different combinations of letters and numbers. That excess of options has left most stars with an abundance of labels (HD 8890 is one of over 40 designations for Polaris).

The tangle of titles won’t disappear, but the new IAU catalog is a stab at formalizing the more popular names. Before this, only 14 stars (included in the 227) had been formally named, as part of the IAU’s contest to name notable exoplanets and the stars that they orbit (SN: 2/6/16, p. 5). One famous star is returning to its ancient roots. The brightest member of Alpha Centauri, the pair of stars that are among the closest to our solar system, is now officially dubbed Rigil Kentaurus, an early Arabic name meaning “foot of the centaur.”

Women in astronomy


This video says about itself:

How a Team of Female Astronomers Revolutionized Our Understanding of Stars

24 February 2016

At the turn of the 19th century, male astronomers mainly studied galaxies, leaving female scientists wide latitude to research and innovate. Indeed they accomplished truly stellar work. Frebel’s book is “Searching for the Oldest Stars: Ancient Relics from the Early Universe“.

From Science News in the USA:

‘The Glass Universe’ celebrates astronomy’s unsung heroines

Women in the 19th century played underappreciated role in mapping and understanding the stars

By Macon Morehouse

8:00am, November 27, 2016

The Glass Universe
Dava Sobel
Viking, $30

In the early 1880s, Harvard Observatory director Edward Pickering put out a call for volunteers to help observe flickering stars. He welcomed women, in particular — and not just because he couldn’t afford to pay anything.

At the time, women’s colleges were producing graduates with “abundant training to make excellent observers,” Pickering wrote. His belief in women’s abilities carried over when he hired staff, even though critics of women’s higher education argued that women “originate almost nothing, so that human knowledge is not advanced by their work.”

Pickering and his “harem” sure proved the critics wrong.

In The Glass Universe, science writer Dava Sobel shines a light on the often-unheralded scientific contributions of the observatory’s beskirted “computers” who helped chart the heavens. By 1893, women made up nearly half of the observatory’s assistants, and dozens followed in their footsteps.

These women toiled tirelessly, marking times, coordinates and other notations for photographic images of the sky taken nightly and preserved on glass plates — the glass universe. These women’s routine mapping of the stars gave birth to novel ideas that advanced astronomy in ways still instrumental today — from how stars are classified to how galactic distances are measured.

Using diaries, letters, memoirs and scientific papers, Sobel recounts the accomplishments of these extraordinary women, going into enough scientific detail (glossary included) to satisfy curious readers and enough personal detail to bring these women’s stories to life.

Sobel traces the origin of the glass universe back to heiress Anna Palmer Draper. The book opens in 1882 with her exulting in hosting a party for the scientific glitterati under the glowing and novel Edison incandescent lights. Her husband, Henry Draper, a doctor and amateur astronomer, had pioneered a way to “fix” the stars on glass photographic plates. The resulting durable black-and-white images revealed spectral lines that could provide hints to a star’s elements — and eventually so much more. Henry’s premature death five days after the party launched Anna’s philanthropic support of the Harvard Observatory and the creation of the glass universe.

Other women featured in the book had a more hands-on impact on astronomy. For instance, Williamina Fleming came to the United States as a maid. But Pickering soon recognized her knack for mathematics. At the observatory, she read “the rune-like lines of the spectra,” Sobel writes, noticing patterns that led to the first iteration in 1890 of the Draper stellar classification system. That system, still used today, was later refined by the observations of other women.

Henrietta Leavitt, a promising Radcliffe College astronomy student slowly going deaf, joined the staff in 1895. While meticulously tracking the changing brightness of variable stars, she noticed a pattern: The brighter a star’s magnitude, the longer it took to cycle through all its variations. This period-luminosity law, published in 1912, became crucial in measuring the distance to stars. It underpinned Edwin Hubble’s law on cosmic expansion and led to discoveries about the shape of the Milky Way, our solar system’s place far from the galactic center and the existence of other galaxies.

The story belongs, too, to Pickering and his successor, Harlow Shapley. Perhaps partly motivated by economics at a time of shoestring budgets — in 1888, women computers earned just 25cents per hour — these men not only recognized, but also encouraged and heralded the women’s talent.

Sobel takes readers through World War II and a myriad of other moments starring women: first woman observatory head; first woman professor at Harvard (of astronomy, of course); discoveries of binary stars, the prevalence of hydrogen and helium in stars, and the existence of interstellar dust. In some cases, it took male astronomers to make those findings stick — the glass universe had a glass ceiling.

After World War II, radio astronomy emerged, and “the days of the human computer were numbered — by zeros and ones,” Sobel writes. Using film to photograph the stars ended in the 1970s. But the glass universe is far from obsolete. The roughly half-million plates hold the ghosts of pulsars, quasars and other stellar phenomena not even imagined when the plates were made. They also offer the promise of more discoveries to come, perhaps by the next generation of women astronomers.

Many galaxies discovered by astronomers


This video says about itself:

Astronomers just discovered one of the most massive objects in the universe hiding behind the Milky Way

23 November 2016

Through the thick fog of our own galaxy, astronomers have spotted an ultimate prize: one of the largest-known structures in the universe. Called the Vela supercluster, the newly discovered object is a massive group of several galaxy clusters, each one containing hundreds or thousands of galaxies. “I could not believe such a major structure would pop up so prominently” after an observation of that region of space, said Renée Kraan-Korteweg, an astrophysicist at the University of Cape Town in South Africa, in a press release. Kraan-Korteweg and her team published their discovery of the supercluster, named after the constellation Vela where it was found, in the Monthly Notices Letters of the Royal Astronomical Society.

From Science News:

Giant gathering of galaxies discovered hiding on far side of Milky Way

Astronomers plan to investigate Vela supercluster’s gravitational tug

By Christopher Crockett

7:00am, November 23, 2016

An immense wall of galaxies, stretching over 380 million light-years, is hiding beyond the far side of the Milky Way.

Dubbed the Vela supercluster, this galactic horde sits about 800 million light-years away in the constellation Vela, researchers report online November 8 in Monthly Notices of the Royal Astronomical Society Letters. Despite its size and relative proximity, Vela has gone unnoticed because it is largely obscured by our own galaxy.

Superclusters — assemblages of groups of galaxies — are among the largest known structures in the universe. Following up on earlier hints that an uncharted supercluster might lurk nearby, Renée Kraan-Korteweg, an astronomer at the University of Cape Town in South Africa, and colleagues scoured a patch of sky bisected by a wall of stars that is part of the Milky Way. Using telescopes in South Africa and Australia, they measured distances to 4,432 galaxies and found that many, to the north and south of the wall, appear to be clumped together.

Vela could help solve a long-standing mystery. The Milky Way and dozens of other galaxies in the immediate neighborhood move together through space. Gravity from known superclusters can account for some of that motion, but not all of it. Astronomers don’t yet know the mass — and hence the gravitational influence — of Vela, but it could be partly responsible for nudging us along.

Star-starved galaxies fill the cosmos. As researchers find hundreds of galaxies with scarce starlight, questions pile up. By Christopher Crockett
11:00am, November 29, 2016: here.

More meteorites on moon than expected


CRATER CRAZE Images captured by the Lunar Reconnaissance Orbiter from 2009 to 2015 revealed 222 new impact craters (in yellow) on the moon. Red dots are new craters whose impacts were observed from Earth

From Science News:

Surprising number of meteoroids hit moon’s surface

Lunar images reveal over 200 new craters and about 47,000 undiscovered ‘splotches’

By Emily DeMarco

8:00am, November 16, 2016

The moon is one tough satellite. With no atmosphere, it endures a barrage of incoming asteroids and comets that pit its surface with a constellation of craters. A new map (above) reveals 222 recent impact craters (in yellow), 33 percent more than simulations predicted. Scientists spotted the features by analyzing about 14,000 pairs of before-and-after images captured by the Lunar Reconnaissance Orbiter from 2009 to 2015. (Red dots note new craters whose impacts were observed from Earth.)

The craters — up to 43 meters in diameter — were probably formed by small meteoroids crashing into the crust. Using the image pairs, the researchers created ratio images, which highlight how the impacts alter the reflectance of the moon’s surface. That perspective illuminated the starburst debris patterns around the craters.

The scientists also found about 47,000 “splotches,” faint marks several to tens of meters across. Most result from secondary debris being jettisoned by impacts and spattering the surface, the researchers propose in the Oct. 13 Nature.

Those splotches would “churn” the upper two centimeters of lunar soil in about 81,000 years, more than 100 times faster than previous predictions that didn’t include the smudges, researchers say. That revelation could improve interpretations of remote-sensing data and help engineers design equipment to better withstand the occasional speckling of soil, says study coauthor Mark Robinson, a planetary geologist at Arizona State University in Tempe. “All of the images we’re taking … and the discoveries we’re making are feeding forward into future human exploration of the moon,” he says.

Supermoon, 14 November 2016


This video from the USA says about itself:

14 October 2016

Nothing beats a bright and beautiful “supermoon.” Except maybe, three supermoons! 2016 ends with a trio of full moons at their closest points to Earth.

From eNatureBlog in the USA:

Don’t Miss Monday’s Supermoon

Tuesday, November 08, 2016 by eNature

November’s full moon is special this year.

It’s not only a supermoon — which looks larger to skywatchers than a “regular” full moon — it will be the closest full moon to Earth since January 1948! NASA says we won’t see a full moon this large again until Nov. 25, 2034.

The full moon officially happens next Monday at 8:52 A.M. Eastern Standard Time. So it won’t be visible along the East Coast at the exact moment of fullness, but it will on the West Coast.

So What Makes The Moon Look So Big?

Because the moon’s orbit around Earth is an elliptical shape the moon can be closer or farther from the Earth’s surface depending on where it is in its orbit. The point when our lunar companion is closest to Earth is called perigee. Apogee is the opposite—when the moon is at its furthest point from Earth.

This month, the perigee occurs Nov. 14 at about 6 A.M. EST— within two hours of the moon becoming officially full — meaning that we will see an extra-super, perigee full moon.

So Just How Close Is The Moon?

The distance between Earth and the moon ranges from 221,208 miles at its closest approach to 252,898 miles at its farthest. That’s a difference of about 32,000 miles.

This month, perigee (and the full moon) occurs at 221,524 miles between Earth and the moon, just 316 miles from its nearest possible location. So you can see why the moon will look so big!

What Exactly Is A “Supermoon”

Astrologer Richard Nolle defined the term back in 1979, but its use has really taken off in the past few years. It often it seems that every moon is a supermoon in breathless headlines on the internet, but the term has a very specific meaning.

Nolle specifically defined a “supermoon” as a new or full moon that occurs when the moon is within 90 percent of its closest approach to Earth in a given orbit. And this week’s full moon occurs when the moon is within 99% of its closest approach, so it clearly meets the definition.

But It’s Not All Happening In The Sky

The supermoon also has an impact on coasts and bays. From November through February, the highest tides, known as “king tides”, sweep along the shores during full moons.

The sun is the closest to Earth during those months and the combined gravity of it and the moon working together increases tidal ranges during that time. The tides get even higher during “supermoons” simply because the moon is that much closer to Earth than it normally is.

So When To Look For The Supermoon

On the East Coast , the nearly-full moon rises at 4:30 P.M. this Sunday afternoon , while the sun sets at around 5:00 P.M. The following morning, the moon sets at 6:36 A.M. — so if you scoot out of bed around 5 A.M., you’ll see the moon low in the western sky plump and full. The full moon rises Monday evening at 5:30 p.m., so look for it close to the eastern horizon.

The timing is similar for other parts of the country, the Naval Observatory provides rise and set times for the moon and sun.

The next perigee full moon occurs Dec. 1, the third such moon in an October-November-December lunar trifecta. After that, there will be a perigee full moon on Jan. 1-2, 2018, when the moon and the Earth will be 221,559 miles apart.

So don’t miss out next week!

Jupiter, Mars, Saturn space news


This video says about itself:

Juno Listens to Jupiter’s Auroras

2 September 2016

Thirteen hours of radio emissions from Jupiter’s intense auroras are presented here, both visually and in sound. The data was collected when the spacecraft made its first orbital pass of the gas giant on Aug 27, 2016, with all spacecraft instruments turned on. The frequency range of these signals is from 7 to 140 kilohertz. Radio astronomers call these “kilometric emissions” because their wavelengths are about a kilometer long.

The full story and more images from Juno‘s first pass of Jupiter with all instruments on is here.

From Science News:

Juno spacecraft goes into ‘safe mode’, continues to orbit Jupiter

by Christopher Crockett

6:57pm, October 19, 2016

PASADENA, Calif. — NASA’s Juno spacecraft, in orbit around Jupiter since July 4, is lying low after entering an unexpected “safe mode” early on October 19. A misbehaving valve in the fuel system, not necessarily related to the safe mode, has also led to a delay in a planned engine burn that would have shortened the probe’s orbit.

Juno turned off its science instruments and some other nonessential components this morning at 1:47 a.m. EDT after computers detected some unexpected situation, mission head Scott Bolton reported at an October 19 news conference. The spacecraft was hurtling toward its second close approach to the planet, soaring about 5,000 kilometers from the cloud tops. It has now passed that point and is moving back away from the planet with all science instruments switched off.

The rocket firing was intended to take Juno from a 53.5-day orbit to a 14-day orbit. Juno can stay in its current orbit indefinitely without any impact on the science goals, Bolton said. The goal of the mission — to peer deep beneath Jupiter’s clouds — depends on the close approaches that it makes with every orbit, not how quickly it loops around. “We changed to a 14-day orbit primarily because we wanted the science faster,” he said. “But there’s no requirement to do that.”

For now, mission scientists are trying to figure what happened with the fuel valve and what triggered the safe mode before proceeding with further instructions to the probe.

First peek under clouds reveals Jupiter’s surprising depths. Colorful bands stretch hundreds of kilometers inward, Juno spacecraft data show. By Christopher Crockett, 9:00am, October 21, 2016: here.

Also from Science News:

Mission scientists await signal from Mars lander

ExoMars probe went silent before touchdown

by Christopher Crockett

5:16pm, October 19, 2016

From the European Space Agency:

20 October 2016

Essential data from the ExoMars Schiaparelli lander sent to its mothership Trace Gas Orbiter during the module’s descent to the Red Planet’s surface yesterday has been downlinked to Earth and is currently being analysed by experts.

Early indications from both the radio signals captured by the Giant Metrewave Radio Telescope (GMRT), an experimental telescope array located near Pune, India, and from orbit by ESA’s Mars Express, suggested the module had successfully completed most steps of its 6-minute descent through the martian atmosphere. This included the deceleration through the atmosphere, and the parachute and heat shield deployment, for example.

But the signals recorded by both Pune and Mars Express stopped shortly before the module was expected to touchdown on the surface. Discrepancies between the two data sets are being analysed by experts at ESA’s space operations centre in Darmstadt, Germany.

ExoMars mission has both success and failure: here.

Experts don’t agree on age of Saturn’s rings. Data from orbiting Cassini craft may help resolve debate. By Christopher Crockett, 8:53am, October 20, 2016: here.

Possibly cloudy forecast for parts of Pluto. Bright patches in New Horizons images hint at rare atmospheric formation. By Christopher Crockett, 3:05pm, October 19, 2016: here.

WE’RE STILL MOURNING PLUTO’S PLANET DEMOTION But there might just be another ninth planet out there. [NYT]

Spacecraft Schiaparelli landing on Mars today


This video says about itself:

5 October 2016

Visualisation of the ExoMars Schiaparelli module entering and descending through the martian atmosphere to land on Mars.

Schiaparelli will enter the atmosphere at about 21 000 km/h and in less than six minutes it will use a heatshield, a parachute and thrusters to slow its descent before touching down in the Meridiani Planum region close to the equator, absorbing the final contact with a crushable structure.

The entire process will take less than six minutes: the animation has been sped up.

Schiaparelli is set to separate from the Trace Gas Orbiter on 16 October, after a seven-month cruise together through space, and will enter the atmosphere on 19 October at 14:42 GMT.

For an overview of the key timings and altitudes corresponding to the events portrayed in this animation see the Schiaparelli descent sequence graphic, see here.

Both Schiaparelli and the Mars scenery in this animation were computer generated.

More about ExoMars: here.

From Science News:

ExoMars mission set to arrive at Red Planet on October 19

Lander will touch down on Mars and a spacecraft will go into orbit around planet

by Christopher Crockett

5:30pm, October 18, 2016

Mars is about to get another visitor. The European Space Agency’s ExoMars mission arrives at the Red Planet on October 19. A spacecraft known as the Trace Gas Orbiter will go into orbit around Mars while a lander named Schiaparelli will touch down on the surface.

ESA will live stream the landing starting at 9 a.m. EDT on October 19.

The arrival ends a roughly seven-month journey. Schiaparelli, which separated from the orbiter on October 16, is expected to enter the Martian atmosphere at 10:42 a.m. and land in a plain dubbed Meridiani Planum about six minutes later. Parachutes will ease its entry and rockets will slow the lander down until it is about two meters from the ground, at which point it will drop the rest of the way, cushioned by a collapsible structure.

Schiaparelli will test technology needed for a future European Mars rover. The lander doesn’t have a long-term power source, so it will last for only a few Martian days. But it is carrying a few scientific instruments, such as a camera and weather sensors.

The orbiter will stick around to study trace gases such as methane in the Martian atmosphere. It will eventually become a communication hub between Earth and another European Mars rover expected to arrive in 2021.

From the ExoMars FAQ page:

The ExoMars programme is a cooperation between ESA and the Russian space agency, Roscosmos. Roscosmos is providing the Proton rockets to launch both missions to Mars, along with contributions to the scientific payload. On the 2016 mission, two of the four science instrument packages on the TGO are European-led and two are Russian-led, while the Schiaparelli package is European-led. The 2020 mission comprises a European-led rover and a Russian-led surface science platform. NASA also contributes some equipment to both missions. …

Participating countries outside Europe are Russia, the United States, Canada, and Israel.

The Schiaparelli Mars lander, missing in action since its October 19 descent, dinged the surface of the Red Planet. A black spot framed by dark rays of debris mark the lander’s final resting place, the European Space Agency reports online October 27. Its parachute, still attached to the rear heat shield, lies about 1.4 kilometers to the south, new images from the Mars Reconnaissance Orbiter show. The front heat shield, ejected about four minutes into the descent, sits roughly 1.4 kilometers to the east of the impact site: here.