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AAS NOVA — Research Highlights 2019

Posted: Fri Jan 04, 2019 5:56 pm
by bystander

Occultations Suggest No Rings for Ultima Thule

Posted: Fri Jan 04, 2019 6:03 pm
by bystander
Occultations Suggest No Rings for Ultima Thule
NOVA | American Astronomical Society | 2019 Jan 02
Susanna Kohler wrote:
What did you do on New Year’s Eve this year? Whatever it was, it probably wasn’t quite as extreme as what the New Horizons spacecraft was doing: passing by 2014 MU69 in the most distant flyby of any object in our solar system.

Today, we’ll get our first detailed look at 2014 MU69 — nicknamed Ultima Thule — from high-resolution data arriving from New Horizons. But while we wait, we can take a moment to explore what we’ve already learned about this small body in our outer solar system. ...

Limits on a Ring System at 2014 MU69 from Recent Stellar Occultations ~ Eliot F. Young et al

Are Fast Radio Bursts from Flaring Magnetars?

Posted: Fri Jan 18, 2019 7:06 pm
by bystander
Are Fast Radio Bursts from Flaring Magnetars?
NOVA | American Astronomical Society | 2019 Jan 16
Susanna Kohler wrote:
Could the mysterious fast-radio-burst signal FRB 121102 be emitted from a flaring, strongly magnetic neutron star? In a new study, two scientists explore the evidence. ...

A Concordance Picture of FRB 121102 as a Flaring Magnetar Embedded
in a Magnetized Ion–Electron Wind Nebula
~ Ben Margalit, Brian D. Metzger
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viewtopic.php?t=37592
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Can Blue Stragglers Be Used to Tell Time?

Posted: Fri Jan 18, 2019 7:14 pm
by bystander
Can Blue Stragglers Be Used to Tell Time?
NOVA | American Astronomical Society | 2019 Jan 18
Kerry Hensley wrote:
As stars age, they gradually lose angular momentum and spin more slowly. This process occurs so predictably for normal, solar-type stars that we can treat them as cosmic clocks using a technique called gyrochronology. But could the same strategy be applied to an unusual type of main-sequence star called blue stragglers? ...

Observations of Spin-Down in Post-Mast-Transfer Stars and
the Possibility for Blue Straggler Gyrochronology
~ Emily Leiner et al

Taking Note of Molecules in Space

Posted: Mon Jan 28, 2019 5:40 pm
by bystander
Taking Note of Molecules in Space
NOVA | American Astronomical Society | 2019 Jan 23
Susanna Kohler wrote:
What do methylidyne, cyanamide, vinyl alcohol, and rugbyballene all have in common? They’re all molecules that have been detected in space — and they’re all included in a recent census of our universe’s chemical makeup. ...

2018 Census of Interstellar, Circumstellar, Extragalactic,
Protoplanetary Disk, and Exoplanetary Molecules
~ Brett A. McGuire

Eclipses of a Scalding Hot Planet

Posted: Mon Jan 28, 2019 5:48 pm
by bystander
Eclipses of a Scalding Hot Planet
NOVA | American Astronomical Society | 2019 Jan 25
Susanna Kohler wrote:
What’s the atmosphere like on the hottest planet we’ve ever discovered? A new study suggests this toasty world may also be cloudless. ...

A Ground-Based Near-Ultraviolet Secondary Eclipse Observation of KELT-9b ~ Matthew J. Hooton et al
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The Hunt for Enormous Early Stars

Posted: Fri Feb 01, 2019 4:03 pm
by bystander
The Hunt for Enormous Early Stars
NOVA | American Astronomical Society | 2019 Jan 30
Susanna Kohler wrote:
The collapse of enormous stars in our early universe may have given birth to the first supermassive black holes. But will we be able to find these early, giant stars to test this theory? ...

On the Detection of Supermassive Primordial Stars ~ Marco Surace et al

Re: Eclipses of a Scalding Hot Planet

Posted: Fri Feb 01, 2019 4:27 pm
by Ann
bystander wrote: Mon Jan 28, 2019 5:48 pm Eclipses of a Scalding Hot Planet
NOVA | American Astronomical Society | 2019 Jan 25
Susanna Kohler wrote:
What’s the atmosphere like on the hottest planet we’ve ever discovered? A new study suggests this toasty world may also be cloudless. ...

A Ground-Based Near-Ultraviolet Secondary Eclipse Observation of KELT-9b ~ Matthew J. Hooton et al
viewtopic.php?t=37256
AAS Nova wrote:

Since the only suitable space-based near-UV coverage right now is provided by Hubble — which won’t be around forever — it’s an important outcome that a ground-based telescope has proven capable of making these measurements. Hooton and collaborators’ work demonstrates that even when Hubble is no longer an option, we will still be able to obtain valuable observations of bizarre planets like Kelt-9b.
It will be an enormous loss when there is no space telescope capable of looking out into space and detecting UV light any more.

Ann

Update on the Search for Planets with TESS

Posted: Sat Feb 02, 2019 4:41 pm
by bystander
Update on the Search for Planets with TESS
NOVA | American Astronomical Society | 2019 Feb 01
Kerry Hensley wrote:
What’s the news coming from NASA’s newest planet hunter, the Transiting Exoplanet Survey Satellite (TESS)? Launched in April 2018, TESS is expected to discover tens of thousands of exoplanets orbiting the nearest and brightest stars. Now that observations are underway, what exciting discoveries have been made? Read on for an update from just a few of the latest TESS studies published in AAS journals. ...

TESS Discovery of a Transiting Super-Earth in the π Mensae System ~ Chelsea X. Huang et al TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844 ~ Roland Vanderspek et al HD 202772A b: A Transiting Hot Jupiter around a Bright,
Mildly Evolved Star in a Visual Binary Discovered by TESS
~ Chelsea X. Huang et al Light Curves for All Stars Observed in TESS Full-frame Images: Sector 1 and Beyond ~ Ryan J. Oelkers, Keivan G. Stassun
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When Stellar and Black-Hole Binaries Meet

Posted: Fri Feb 08, 2019 9:00 pm
by bystander
When Stellar and Black-Hole Binaries Meet
NOVA | American Astronomical Society | 2019 Feb 06
Susanna Kohler wrote:
You might think that a passing star getting ripped apart by a supermassive black hole sounds like more than enough drama. But a new study takes this picture a step further, exploring what happens when a stellar binary interacts with a pair of supermassive black holes. ...

Stellar Binaries Incident on Supermassive Black Hole Binaries: Implications for
Double Tidal Disruption Events, Calcium-Rich Transients, and Hypervelocity Stars
~ Eric R. Coughlin et al

Citizen Scientists Find an Unexpected Planet

Posted: Fri Feb 08, 2019 9:09 pm
by bystander
Citizen Scientists Find an Unexpected Planet
NOVA | American Astronomical Society | 2019 Feb 08
Susanna Kohler wrote:
In today’s era of big data, we often rely on computers to do sorting, searching, and analyzing. Sometimes, however, there’s just no substitute for the human eye and brain, which comes pre-loaded with excellent pattern-detection capabilities. This is where citizen science come in. ...

K2-288Bb: A Small Temperate Planet in a Low-mass Binary
System Discovered by Citizen Scientists
~ Adina D. Feinstein et al
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Dwarf Galaxy or Giant Globular Cluster?

Posted: Mon Feb 18, 2019 6:51 pm
by bystander
Dwarf Galaxy or Giant Globular Cluster?
NOVA | American Astronomical Society | 2019 Feb 13
Susanna Kohler wrote:
You might think that we’d already discovered all the large clusters of stars orbiting our galaxy. Surprisingly, there are still detections to be made — such as the recently discovered cluster FSR 1758. But is this large group of stars an enormous globular cluster? Or a newly detected dwarf galaxy? ...

A Sequoia in the Garden: FSR 1758 - Dwarf Galaxy or Giant Globular Cluster? ~ R.H. Barba et al

Can Magnetic Fields Help Planetesimals Form?

Posted: Mon Feb 18, 2019 6:56 pm
by bystander
Can Magnetic Fields Help Planetesimals Form?
NOVA | American Astronomical Society | 2019 Feb 15
Kerry Hensley wrote:
Astronomers still don’t fully understand how planets form, especially ultra-dense, iron-rich planets like Mercury. How do trillions of tiny dust grains clump together to make pebbles, planetesimals, and eventually the cores of rocky planets? ...

Seeding the Formation of Mercurys: An Iron-sensitive Bouncing Barrier in Disk Magnetic Fields ~ Maximilian Kruss, Gerhard Wurm

Insights from MU69’s (Lack of) Craters

Posted: Thu Feb 21, 2019 7:10 pm
by bystander
Insights from MU69’s (Lack of) Craters
NOVA | American Astronomical Society | 2019 Feb 18
Susanna Kohler wrote:
One of the joys of getting new data from astronomy missions is the opportunity to test predictions. NASA’s New Horizons space probe is now beaming us data from its flyby of 2014 MU69 — and there’s a lot to learn! ...

Crater Density Predictions for New Horizons Flyby Target 2014 MU69 ~ Sarah Greenstreet et al

Holding Together a Speeding Cloud

Posted: Thu Feb 21, 2019 7:16 pm
by bystander
Holding Together a Speeding Cloud
NOVA | American Astronomical Society | 2019 Feb 20
Susanna Kohler wrote:
High-velocity clouds observed in our galaxy’s halo pose a conundrum: given their tenuous nature and large speeds, why haven’t they been ripped apart? New observations of one such cloud now provide a possible answer. ...

Constraining the Magnetic Field of the Smith High-velocity Cloud Using Faraday Rotation ~ S. K. Betti et al

A Hazy Day Around TRAPPIST-1?

Posted: Wed Feb 27, 2019 7:18 pm
by bystander
A Hazy Day Around TRAPPIST-1?
NOVA | American Astronomical Society | 2019 Feb 22
Susanna Kohler wrote:
The multi-planet system around the star TRAPPIST-1 is an excellent target for probing exoplanet atmospheres. A new study explores whether the skies of these exoplanets are likely cloudy or clear. ...

Limits on Clouds and Hazes for the TRAPPIST-1 Planets ~ Sarah E. Moran et al

Clues from Hubble a Year After a Neutron-Star Merger

Posted: Sat Mar 02, 2019 6:17 pm
by bystander
Clues from Hubble a Year After a Neutron-Star Merger
NOVA | American Astronomical Society | 2019 Feb 27
Susanna Kohler wrote:
When two neutron stars merged in August of 2017, telescopes around the world watched the fireworks that came next. But it’s not just the seconds and minutes after merger that can teach us about what happened! Hubble observations of the afterglow a year later are now providing new clues. ...

The Optical Afterglow of GW170817 at One Year Post-Merger ~ G.P. Lamb et al
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Solving a Stellar Abundance Problem

Posted: Sat Mar 02, 2019 6:25 pm
by bystander
Solving a Stellar Abundance Problem (with a Little Help from Our Oceans)
NOVA | American Astronomical Society | 2019 Mar 01
Kerry Hensley wrote:
When solving mysteries about distant astronomical objects, sometimes it pays to take inspiration from sources closer to home. In today’s example, strange fluid behavior in the Earth’s oceans — combined with a healthy helping of magnetic fields — may provide the answer to a long-standing puzzle about the changing composition of red-giant stars. ...

Enhanced Mixing in Magnetized Fingering Convection,
and Implications for Red Giant Branch Stars
~ Peter Harrington, Pascale Garaud

Inflating a Super-Puff Planet

Posted: Fri Mar 08, 2019 8:09 pm
by bystander
Inflating a Super-Puff Planet
NOVA | American Astronomical Society | 2019 Mar 04
Susanna Kohler wrote:
Super-puffs — fluffy planets observed to have abnormally low densities — are a problem. According to theoretical models, they shouldn’t exist — and yet we’ve already detected half a dozen of them with Kepler alone. A new study explores what theory might be getting wrong. ...

Dusty Outflows in Planetary Atmospheres: Understanding “Super-Puffs”
and Transmission Spectra of Sub-Neptunes
~ Lile Wang, Fei Dai

First Disrupted Star for a New Survey

Posted: Fri Mar 08, 2019 8:20 pm
by bystander
First Disrupted Star for a New Survey
NOVA | American Astronomical Society | 2019 Mar 06
Susanna Kohler wrote:
What happens when a black hole makes a meal out of a passing star? So far, we’ve only detected a few dozen candidate tidal disruption events to help us answer this question — but now a new player is in the observing game. ...

The First Tidal Disruption Flare in ZTF: From Photometric Selection to Multi-Wavelength Characterization ~ Sjoert van Velzen et al

Reversing Winds on Hot Jupiters

Posted: Tue Mar 12, 2019 5:48 pm
by bystander
Reversing Winds on Hot Jupiters
NOVA | American Astronomical Society | 2019 Mar 08
Susanna Kohler wrote:
Exoplanets HAT-P-7b and CoRoT-2b have an unusual quirk: instead of having eastward equatorial winds, like the majority of hot Jupiters, these two hot Jupiters have westward winds. A new study explores whether magnetic fields cause this odd reversal. ...

Shallow-Water Magnetohydrodynamics for Westward Hotspots on Hot Jupiters ~ A.W. Hindle, P.J. Bushby, T.M. Rogers

Giant Stars in Our Black Hole’s Neighborhood

Posted: Sat Mar 16, 2019 5:01 pm
by bystander
Giant Stars in Our Black Hole’s Neighborhood
NOVA | American Astronomical Society | 2019 Mar 15
Kerry Hensley wrote:
How does a supermassive black hole affect its stellar neighbors? One way to explore this question is by searching for old, giant stars in the extreme environs of the galactic center. ...

Spectroscopic Detection of a Cusp of Late-Type Stars
around the Central Black Hole in the Milky Way
~ M. Habibi

Missing Halos in the High-Energy Sky

Posted: Fri Mar 22, 2019 5:35 pm
by bystander
Missing Halos in the High-Energy Sky
NOVA | American Astronomical Society | 2019 Mar 18
Susanna Kohler wrote:
What’s going on in our high-energy sky? Powerful phenomena abound in our universe, and they can produce photons with tremendous energies. A new study explores a high-energy mystery from one of these sources: active galactic nuclei, or AGN. ...

Missing Gamma-Ray Halos and the Need for New Physics in the Gamma-Ray Sky ~ Avery E. Broderick et al

Looking for Life? Try Around K Dwarfs

Posted: Fri Mar 22, 2019 5:39 pm
by bystander
Looking for Life? Try Around K Dwarfs
NOVA | American Astronomical Society | 2019 Mar 20
Susanna Kohler wrote:
Signs of life in planetary atmospheres are hard to spot! A new study suggests that the best strategy for discovering them may be to look at planets orbiting K-dwarf stars. ...

The K Dwarf Advantage for Biosignatures on Directly Imaged Exoplanets ~ Giada N. Arney
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Flares, Waves, Jets, and Ejections

Posted: Wed Mar 27, 2019 6:22 pm
by bystander
Flares, Waves, Jets, and Ejections
NOVA | American Astronomical Society | 2019 Mar 22
Susanna Kohler wrote:
Our Sun often exhibits a roiling surface full of activity. But how do the different types of eruptions and disturbances we see relate to one another? Observations of one explosive jet are helping us to piece together the puzzle. ...

A Blowout Jet Associated with One Obvious Extreme-Ultraviolet
Wave and One Complicated Coronal Mass Ejection Event
~ Y. H. Miao et al