Weekly Space Hangout – November 11, 2016: Pat Ammons of Space Camp, and Bob King of “Night Sky With The Naked Eye”

Host: Fraser Cain (@fcain)

Special Guests:
Pat Ammons is Director of Communications, U.S. Space & Rocket Center, to discuss SpaceCamp.

Bob King is a UT contributor who will be joining us to promote his new book “Night Sky with the Naked Eye.”

Guests:

Kimberly Cartier ( KimberlyCartier.org / @AstroKimCartier )
Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg)

Their stories this week:

What will Trump’s space policy look like?

Is NASA preparing to abandon Orion?

An exotic pair of stellar remnants

Subaru’s new exoplanet atmosphere instrument

We use a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

If you would like to join the Weekly Space Hangout Crew, visit their site here and sign up. They’re a great team who can help you join our online discussions!

If you would like to sign up for the AstronomyCast Solar Eclipse Escape, where you can meet Fraser and Pamela, plus WSH Crew and other fans, visit our site linked above and sign up!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page.

Astronomers Catch a Galactic Threesome in the Act

An enormous and incredibly luminous distant galaxy has turned out to actually be three galaxies in the process of merging together, based on the latest observations from ALMA as well as the Hubble and Spitzer space telescopes. Located 13 billion light-years away, this galactic threesome is being seen near the very beginning of what astronomers call the “Cosmic Dawn,” a time when the Universe first became illuminated by stars.

“This exceedingly rare triple system, seen when the Universe was only 800 million years old, provides important insights into the earliest stages of galaxy formation during a period known as ‘Cosmic Dawn’ when the Universe was first bathed in starlight,” said Richard Ellis, professor of astronomy at Caltech and member of the research team. “Even more interesting, these galaxies appear poised to merge into a single massive galaxy, which could eventually evolve into something akin to the Milky Way.”

In the image above, infrared data from NASA’s Spitzer Space Telescope are shown in red, visible data from NASA’s Hubble Space Telescope are green, and ultraviolet data from Japan’s Subaru telescope are blue. First discovered in 2009, the object is named “Himiko” after a legendary queen of Japan.

The merging galaxies within Himiko are surrounded by a vast cloud of hydrogen and helium, glowing brightly from the galaxies’ powerful outpouring of energy.

What’s particularly intriguing to astronomers is the noted lack of heavier elements like carbon in the cloud.

“This suggests that the gas cloud around the galaxy is actually quite primitive in its composition,” Ellis states in an NRAO video, “and has not yet been enriched by the products of nuclear fusion in the stars in the triple galaxy system. And what this implies is that the system is much younger and potentially what we call primeval… a first-generation object that is being seen. If true that’s very very exciting.”

Further research of distant objects like Himiko with the new high-resolution capabilities of ALMA will help astronomers determine how the Universe’s first galaxies “turned on”… was it a relatively sudden event, or did it occur gradually over many millions of years?

Watch the full video from the National Radio Astronomy Observatory below:

The research team’s results have been accepted for publication in the Astrophysical Journal.

Source: NASA/JPL press release and the NRAO.

Unraveling the Secrets of Type Ia Supernovae: a New Two-Minute Thesis

The folks over at PHD Comics have put together a new video in their Two-Minute Thesis series, this one featuring Ph.D candidate Or Graur of the University of Tel Aviv and the American Museum of Natural History discussing the secret lives — and deaths — of astronomers’ “standard candles” of universal distance, Type Ia supernovae.

Judging distances across intergalactic space isn’t easy, so in order to figure out how far away galaxies are astronomers have learned to use the light from Type Ia supernovae, which flare up with the brilliance of 5 billion Suns… and rather precisely so.

Type Ia supernovae are thought to be created from a pairing of two stars: one super-dense white dwarf which draws in material from a binary companion until a critical mass — about 40% more mass than the Sun – is reached. The overpacked white dwarf suddenly undergoes a rapid series of thermonuclear reactions and explodes in an incredibly bright outburst of material and energy.

But exactly what sorts of stellar pairs lead to Type Ia supernovae and how frequently they occur aren’t known, and that’s what Ph.D candidate Or Graur is aiming to learn more about.

Read more: A New Species of Type Ia Supernova?

“We don’t really know what kind of star it is that leads to these explosions, which is kind of embarrassing,” says Graur. “The companion star could be a regular star like our Sun, a red giant or supergiant, or another white dwarf.”

Because stars age at certain rates, by looking deeper into space with the Hubble and Subaru telescopes Graur hopes to determine how often and when in the Universe’s history Type Ia supernovae occur, and thus figure out what types of stars are most likely responsible.

“My rate measurements favor a second white dwarf as the binary companion,” Graur says, “but the issue is far from settled.”

Watch the video for the full story, and visit PHD TV and PHD Comics for more great science illustrations.

Video: PHDComics. Animation: Jorge Cham. Series Producer: Meg Rosenburg. Inset image: merging white dwarfs causing a Type Ia supernova. (NASA/CXC/M Weiss)

Here There Be Planets: Stellar Disk Gap May Reveal Newborn Worlds

HiCIAO near-infrared image of the protoplanetary disk around PDS 70. The circular mask hides the star itself, as well as a smaller internal disk structure. (Credit: NAOJ)

Over the past couple of decades astronomers have figured out several methods for finding planets around other stars in our galaxy. Some have revealed their presence by the slight “wobble” they impart to their host stars as they orbit, while others have been discovered as they pass in front of their stars from our perspective, briefly dimming the light we see.

Now, some astronomers think they may have identified the presence of multiple planets, based on a large gap found in the disk of  gas and dust surrounding a Sun-like star 460 light-years from Earth.

Using the High Contrast Instrument for the Subaru Next Generation Adaptive Optics (HiCIAO) mounted on Japan’s 8.2-meter optical-infrared Subaru telescope atop Mauna Kea in Hawaii, an international team of astronomers targeted PDS 70, a young star (10 million years old) about the same mass as the Sun located 460 light-years away in the constellation Centaurus.

The near-infrared observations made by HiCIAO reveal a protoplanetary disk surrounding PDS 70. This disk is composed of gas and dust and extends billions of miles out from the star. Quite literally the stuff that planets are made of, it’s a disk much like this that our solar system likely started out as over 4.6 billion years ago.

“Thanks to the powerful combination of the Subaru Telescope and HiCIAO, we are able to probe the disks around Sun-like stars. PDS 70 shows how our solar system may have looked in its infancy. I want to continue this kind of research to understand the history of planetary formation.”

– Team Leader Jun Hashimoto (NAOJ)

Within PDS 70’s disk are several large gaps positioned at varying distances from the star itself, appearing as dark regions in the near-infrared data. These gaps — especially the largest, located about 70 AU from the star — are thought to be the result of newly-formed planets having cleared the surrounding space of dust and smaller material. It’s also believed that multiple planets may be present since, according to the team, “no single planet, regardless of how heavy or efficient it is in its formation, is sufficient to create such a giant gap.”

In addition to the large disk structure and outer gap, PDS 70 also has a smaller disk located only 1 AU away. (This disk is obscured by the HiCIAO mask in the image above.)

Further observations will be needed to locate any actual exoplanets directly, since the light from the star and scattered light within the disk makes it difficult — if not impossible with current technology — to detect the incredibly faint light reflected by planets.

Still, it’s fascinating to come across what may very well be a solar system in its infancy, giving us a glimpse back in time to our own formation.

“Direct imaging of planets in the process of forming in protoplanetary disks would be ideal so that we can learn when, where, and how planets form,” said team leader Ruobing Dong of Princeton University.

Read more on the NAOJ website for the Subaru Observatory here.

The goal of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) Project is to study the disks around less massive stars like the Sun.

Inset image: Artist’s rendition of PDS 70 and its two protoplanetary disks (NAOJ)

Rare Rectangle Galaxy Discovered

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It’s being called the “emerald-cut galaxy” — recently discovered by an international team of astronomers with the Swinburne University of Technology in Australia, LEDA 074886 is a dwarf galaxy located 70 million light-years (21 Mpc) away, within a group of about 250 other galaxies.

“It’s an exciting find,” Dr. Alister Graham, lead author and associate professor at Swinburne University Center for Astrophysics and Supercomputing told Universe Today in an email. “I’ve seen thousands of galaxies, and they don’t look like this one.”

The gem-cut galaxy was detected in a wide-field image taken with the Japanese Subaru Telescope by astrophysicist Dr. Lee Spitler.

It’s thought that the unusual shape is the result of a collision between two galaxies, possibly two former satellite galaxies of the larger NGC 1407, the brightest of all the approximately 250 galaxies within its local group.

“At first we thought that there was probably some gravitational-tidal interaction which has caused LEDA 074886 to have its unusual shape, but now we’re not so sure, as its features better match that of two colliding disk galaxies,” Dr. Graham said.

In addition to being oddly angular, LEDA 074886 also features a stellar disk inside it, aligned edge-on to our line of sight. This disk of stars is rotating at speeds of up to 33 km/second, although it can’t be discerned if it has a spiral structure or not  because of our position relative to it.

False-color image of LEDA 074886 taken with Subaru Telescope's Suprime-Cam. Contrast enhanced to show central disk structure. (Graham et al.)

 “It’s one of those things that just makes you smile because it shouldn’t exist, or rather you don’t expect it to exist.”

– Dr. Alister Graham, Associate Professor, Swinburne University of Technology

Although rectangular galaxies are rare, we may eventually become part of one ourselves.

“Curiously,” Dr. Graham said, “if the orientation was just right, when our own disc-shaped galaxy collides with the disc-shaped Andromeda galaxy about three billion years from now we may find ourselves the inhabitants of a square-looking galaxy.”

(Let’s hope that it’s still “hip to be square” in another 3 billion years!)

The team’s paper will be published in The Astrophysical Journal. Read more on the Swinburne University press release here or on the Subaru Telescope site.

Image credit: Swinburne University of Technology