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

Paranal

Paranal

Paranal

Lochnagar

Lochnagar

Lochnagar

Iceland

Iceland

Iceland

Andes

Andes

Andes

Yosemite Falls

Yosemite

Yosemite

Jellyfish

Jellyfish

Jellyfish

La Rochelle

La Rochelle

La Rochelle

Aurora Borealis

Northern Lights

Northern Lights

Arthur’s Pass

Arthur's Pass

Arthur’s Pass

Sandfly Bay

Sandfly Bay

Sandfly Bay

Wallpaper

Scotland

Scotland

Lochnagar

Scotland

Scotland

Wall Art

Mt Maunganui

Mt Maunganui

Place de Vosges

Paris

Paris

Delicate Arch

Delicate Arch

Delicate Arch

Landscape Arch

Arches

Arches

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.

Sunset

Borneo

Borneo

Waxeye

Waxeye

Waxeye

Snowdonia

Wales

Wales

Heidelberg

Heidelberg

Heidelberg

Mauna Kea Frost

Frost

Frost

Laser

I’m in Hawaii up Mauna Kea doing some observing on the JCMT. Here’s the Keck laser guide star, click the image for a quick movie of the Earth turning.

Keck Laser

Keck Laser

Falcon

Kenilworth Castle

Kenilworth Castle

Mugshot

Here’s the real reason I signed up for I’m a scientist, I needed a new mug!

Mugshot

Grant wins!

Very fun event where UK school kids get to quiz scientists in real time. Crazy two weeks of intense chats!

Boat

Seen from the Cook Strait Ferry

Balancing Act

Sandfly Bay

Tractor

Tractor, NZ style

Suburban Canberra

Bruce

Beach Huts

Beach Huts in Bournemouth

Moss Glen Falls

Having coffee in Lyndhurst (Dorset) the other day I thought a photo on the wall looked familiar. Turns out I have a photo of the same waterfall from 2007, which is in Vermont (USA).

Moss Glen Falls

Seen in Lyndhurst

Kölner Dom

Cologne

Vulture

Vulture

Indian Garden

Grand Canyon

Shoshone Point Sunrise

Grand Canyon

Paris

Eiffel Tower

NZL 3 – IND 1

Olympics

Olympics

Glaswaldsee

Glaswaldsee

Alhambra

Davos

Davos

Davos

M11