Author Archive for grantkennedy

HD 98800 – the polar circumbinary disk

As outlined in the paper and the press release (free PDF here), we have discovered that the HD 98800 quadruple star system hosts a disk that orbits at right angles to the binary it surrounds.

Here is Fig. 1 from the paper, which shows the setup. If the geometry of the disk around the inner binary doesn’t make sense, try taking a look at this simulation.

The HD 98800 system
The HD 98800 system

What does this show? The system has two binaries, A and B, which orbit each other at a distance of about the Pluto-Sun distance. Since both A and B are binaries, the individual stars are called Aa and Ab, and Ba and Bb. The “inner binary” BaBb is surrounded by a ring of gas and dust about the size of the Asteroid belt, this is shown in the right panel. All that is then orbiting the other binary, AaAb. The curious thing is that none of the orbital planes are aligned, and the BaBb plane is at right angles to the plane of the disk.

This system should prove very valuable to people that are interested in disk physics – here we can quantify the effects of the stars on the disk so compare the data with models. Of course, it’s possible that the disk is forming planets, and there is evidence that suggests this is underway, meaning that polar circumbinary planets may exist and be found in the future!

Cairngorms

Scotland

Scotland

Wedding

Wedding

Wedding

Bonfire

Bonfire

Bonfire

Car

Wedding

Tongariro Crossing

Tongariro Crossing

Tongariro Crossing

VLT

VLT

VLT

Paranal sunset

Paranal

Paranal sunset

oh dear, this makes brexit look like a success #El…

oh dear, this makes brexit look like a success #Elections2016(0)

Paranal

Paranal

Paranal

read this https://t.co/Qc8vLndP0S @astropy

read this arxiv.org/abs/1610.03159 @astropy(1)

Lochnagar

Lochnagar

Lochnagar

Deep dip (maybe closer to edge-on than avg) paper…

Deep dip (maybe closer to edge-on than avg) paper I couldn’t remeber today is arxiv.org/abs/1504.03568, observed by @dalcashdvinsky #rkrbrngs(1)

That is the question… #rkrbrngs https://t.co/6nI…

That is the question… #rkrbrngs https://t.co/6nIHmAcoIE

CtSDIjKW8AAj8Dn(1)

Ready for Rocks, Rubble, and Rings at the Lorentz…

Ready for Rocks, Rubble, and Rings at the Lorentz Center @mattkenworthy #rkrbrngs https://t.co/beYHPQxpyQ

CtRA79IWgAA0kHW(0)

Iceland

Iceland

Iceland

Andes

Andes

Andes

My path to @royalsociety funding began on the othe…

My path to @royalsociety funding began on the other side of the world: ??????????????. #ScienceIsGlobal, obviously.(0)

#get??in! #iVoted

#get??in! #iVoted(0)

The difference between Stansted and a shopping mal…

The difference between Stansted and a shopping mall is that in a mall you don’t see people wondering why there isn’t enough seating.(0)

Yosemite Falls

Yosemite

Yosemite

Jellyfish

Jellyfish

Jellyfish

Possible transits of a broken up comet around anot…

Possible transits of a broken up comet around another star – the Cygnids? newscientist.com/article/dn2819…(0)

transits of a broken up comet around another star?…

transits of a broken up comet around another star? the first exo-Pleiades? newscientist.com/article/dn2819…(0)

La Rochelle

La Rochelle

La Rochelle

Aurora Borealis

Northern Lights

Northern Lights

Fantastic crowd at @IoACOA for #eclipse2015 this m…

Fantastic crowd at @IoACOA for #eclipse2015 this morning! http://t.co/tTiZqPiyws

CAhwQQLWYAAp-aU(0)

Arthur’s Pass

Arthur's Pass

Arthur’s Pass

Sandfly Bay

Sandfly Bay

Sandfly Bay

watched the #NZvENG highlights last night, couldn’…

watched the #NZvENG highlights last night, couldn’t understand why they took such a long break between innings(0)

Our work on @ESAHerschel images of tau Ceti gets a…

Our work on @ESAHerschel images of tau Ceti gets a shout out in @sciam scientificamerican.com/article/tau-ce… http://t.co/xKilTY9MvZ

B5H7ANUIAAE6-Kh(0)

Finally, a good use of an electric cart in an amer…

Finally, a good use of an electric cart in an american airpot: Halloween float at #DFW complete with MJ’s Thriller(0)

Wallpaper

Scotland

Scotland

Lochnagar

Scotland

Scotland

Wall Art

Mt Maunganui

Mt Maunganui

Welcome all to sunny Cambridge and #acrosshr. Top…

Welcome all to sunny Cambridge and #acrosshr. Top culture tip for evenings this week: cambridgeshakespeare.com(1)

Wow, when they said welcome to Dullest Internation…

Wow, when they said welcome to Dullest International airport they weren’t kidding.(0)

Place de Vosges

Paris

Paris

my contribution on the LOC so far: #axhr will be t…

my contribution on the LOC so far: #axhr will be the official tag for Characterizing Planetary Systems Across the HR Diagram(0)

LHR lounge news rack filled with papers with headl…

LHR lounge news rack filled with papers with headline “DOOMED AIRLINER”. Nice.(0)

Delicate Arch

Delicate Arch

Delicate Arch

Greeted with Kia Ora at LAX, lovely.

Greeted with Kia Ora at LAX, lovely.(0)

Landscape Arch

Arches

Arches

Champagne powder: I am bemused to admit that it do…

Champagne powder: I am bemused to admit that it does feel a little better underfoot than previous snow I have tried.(1)

Discovery of the Fomalhaut C debris disc

This isn’t a photo for a change. It’s a graphic from a press release about my discovery of a debris disk around Fomalhaut C.

Artists illustration of Fomalhaut C, with Fomalhaut A in the background. Credit: Amanda Smith

Artist’s illustration of Fomalhaut C, with Fomalhaut A in the background. Credit: Amanda Smith

The story has travelled far, including (but not limited to) ABCastrobites, Centauri Dreams, CNES & CNRS (French), Discovery News, Natureslashdot & Universe Today.

Companion’s comets the key to curious exoplanet sy…

Companion’s comets the key to curious exoplanet system? Second disk around the third star in the Fomalhaut system ras.org.uk/news-and-press…(1)

Sunset

Borneo

Borneo

Waxeye

Waxeye

Waxeye

449.4 hours of Spitzer time to survey the Kepler f…

449.4 hours of Spitzer time to survey the Kepler field. Check.(0)

Dive with sharks and rays at the Napier aquarium,…

Dive with sharks and rays at the Napier aquarium, still got ten fingers.(1)