Zooming into M33

This animation flies through the local galactic neighborhood to the Triangulum galaxy (M33), a smaller spiral than our Milky Way galaxy. It first zooms in on one of M33’s bright regions of star birth, the nebula cataloged as NGC 604, a glowing cloud of hot ionized hydrogen gas..

Video Credit: NASA / ESA / STScI

The Ultima Thule Flyby

Ultima Thule is a nickname for the Kuiper Belt Object known as 2104 MU69. The picture above is an overlay of 5 images taken by the Hubble Space Telescope. The images were taken at 10-minute intervals on 24 June, 2014. The positions of 2014 MU69 in the images are shown by the green circles.

On New Year’s Day, 2019, the New Horizons spacecraft will fly by Ultima Thule. The science objectives of the flyby include imaging the KBO to determine its shape, geology, and surface composition. The surrounding environment will be scanned to detect any possible moons, coma, or rings.

New Horizons made its first detection of 2014 MU69 on 16 August, 2018, at a distance 172 million km. At that time, 2014 MU69 appeared as a magnitude 20 object from New Horizon‘s point of view. It won’t appear at naked eye brightness (magnitude 6) until the spacecraft is within 3 to 4 hours of closest approach.

Image Credit: NASA / ESA

Orphan Stars

The soft glow of light between the member galaxies of galaxy cluster MACS J0416.1-2403 is produced by stars that are not part of any individual galaxy. The stars were scattered throughout the cluster long ago when their home galaxies were torn apart by the cluster’s gravitational forces. The homeless stars eventually aligned themselves with the gravity of the overall cluster.

Image Credits: NASA / ESA

A Stellar Wreath

The bright star RS Puppis at the center of this image is surrounded by a cocoon of reflective dust. The super star is ten times more massive than the Sun, 200 times larger, and averages over 15,000 times brighter than the Sun. Averages? Yes, it is one of the most luminous Cepheid variable stars, and its brightness varies rhythmically over a six-week period.

The surrounding nebula flickers in brightness as pulses of light from the Cepheid propagate outwards. By tracking the fluctuation of light in RS Puppis itself and recording the faint reflections of light pulses moving across the nebula, astronomers are able to measure these light echoes and compute the distance to the star with about one percent uncertainty. The distance to RS Puppis is just about 6,500 light-years.

Image Credit: NASA / ESA

Hubble Looks at a Comet

The Hubble Space Telescope photographed Comet 46P/Wirtanen on 13 December, when the comet was roughly12 million km from Earth. In this visible-light image, the comet’s nucleus is hidden in the center of a fuzzy glow from the comet’s coma, the cloud of gas and dust that the comet has ejected because of heating by the Sun during the pass through the inner Solar System. The blue color was applied to the image using to high-resolution grayscale exposures acquired from the Hubble’s Wide Field Camera 3.

Image Credit: NASA