May 27, 2016

H II Region N44 in the Large Magellanic Cloud

H II region N44

Southern part of the spectacular N44 H II region in the Large Magellanic Cloud. The green colour indicates areas that are particularly hot. The field measures 27.5 x 26.5 square arcminutes. North is up and East is left.

Image Credit: ESO

A star set to explode

SBW1

Floating at the centre of this Hubble image is a lidless purple eye, staring back at us through space. This ethereal object, known officially as [SBW2007] 1 but sometimes nicknamed SBW1, is a nebula with a giant star at its centre. The star was originally twenty times more massive than our Sun, and is now encased in a swirling ring of purple gas, the remains of the distant era when it cast off its outer layers via violent pulsations and winds.

But the star is not just any star; scientists say that it is destined to go supernova! 26 years ago, another star with striking similarities went supernova — SN 1987A. Early Hubble images of SN 1987A show eerie similarities to SBW1. Both stars had identical rings of the same size and age, which were travelling at similar speeds; both were located in similar HII regions; and they had the same brightness. In this way SBW1 is a snapshot of SN1987a's appearance before it exploded, and unsurprisingly, astronomers love studying them together.

At a distance of more than 20 000 light-years it will be safe to watch when the supernova goes off. If we are very lucky it may happen in our own lifetimes...

Image Credit: ESA/Hubble, NASA, Nick Rose/Steve Byrne
Explanation from: https://www.spacetelescope.org/images/potw1401a/

Artist's Impression of the Exoplanet 55 Cancri e

Exoplanet 55 Cancri e

This animated illustration shows one possible scenario for the hot, rocky exoplanet called 55 Cancri e, which is nearly two times as wide as Earth. New data from NASA's Spitzer Space Telescope show that the planet has extreme temperature swings from one side to the other-- and a possible reason for this might be the presence of lava pools.

This planet is tidally locked to its star, just as our moon is to Earth, which means that one side always sizzles under the heat of its star while the other side remains in the dark. If the planet were covered in lava, then the hot, sun-facing side of the planet would have liquid lava flows, while the colder, dark side would see solidified lava rock. The hardened lava would be unable to transport heat across the planet, explaining why Spitzer detected that the cold side of the planet is much colder than the hot side.

Such a lava planet, if it exists, would have dust streaming off of it, as illustrated here. Radiation and winds from the nearby star would blow off the material.

Scientists say that future observations with NASA's upcoming James Webb Space Telescope should provide more details about the nature of this exotic world.

Video Credit: NASA/JPL-Caltech
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA20068