The Fornax Dwarf

Fornax_dwarf_galaxyThe Fornax Dwarf Spheroidal is an elliptical dwarf galaxy found in the constellation Fornax. The galaxy is a satellite of the Milky Way and is receding from the us at 53 km/s. It contains six know globular star clusters, an unusually large number for such a small galaxy. Four of them (Fornax 1, 2, 3, and 5) are pictured below.

Image Credits: ESO and ESA

Looking Back to the Hubble Deep Field

The new deep field images from JWST are spectacular, but we learned a lot from Hubble’s earlier deep field images. Let’s take another look.

The stars seem to fly by under warp drive on StarTrek. This video definitely one-ups that. These are galaxies, not stars. Because it takes light a long time to cross the universe, most galaxies visible in the video are seen when the universe was only a fraction of its current age. They were still forming and have unusual shapes compared to modern galaxies. There are no mature looking spiral galaxies such as our Milky Way or the Andromeda galaxy. They had not evolved yet. At the end of the video the virtual observer flies past the furthest galaxies in the HUDF with a redshift past 8. These early low luminosity galaxies probably contained stars emitting light that transformed much of the remaining normal matter in the universe from a cold gas to a hot ionized plasma.

Video Credit: NASA

An Isolated, Irregular Dwarf

NGC 1156 is located around 25 million light-years from Earth in the constellation Aries. It’s a dwarf irregular galaxy and isolated, meaning no other galaxies are close enough to influence its odd shape or star formation. The extreme energy of young stars ionizes hydrogen gas which glows red, while its centre is filled with older stars.

Video Credits: ESA / NASA / R. B. Tully / R. Jansen / R. Windhorst

M33 in Infrared and Radio

This image of the Triangulum galaxy (aka M33) uses far-infrared and radio wavelengths of light. The IR data came from the ES) Herschel mission, ESA’s retired Planck observatory, and two retired NASA missions: the Infrared Astronomy Survey and Cosmic Background Explorer. The radio data came from the Very Large Array, Green Bank Telescope, and IRAM radio telescope.

Image Credits: ESA / NASA / NASA-JPL, Caltech / Christopher Clark (STScI) / E. Koch (University of Alberta) / C. Druard (University of Bordeaux)

Jupiter in Infrared

This false color view from the JWST’s NIRCam instrument’s 2.12 micron filter shows the distinct bands that encircle Jupiter and the planet’s Great Red Spot. The iconic spot appears white in this image because of the way the infrared image was processed. The moon Europa is visible on the left, and its shadow can be seen to the left of the Great Red Spot.

Image Credit: NASA / ESA / CSA/ STScI

The Southern Ring Nebula

The NIRCam and MIRI instruments aboard the James Webb Space Telescope captured the data used to create these false color infrared images of this planetary nebula NGC 3132 (aka the Southern Ring Nebula).

The near infrared (NIRCam) image is on the left. The mid infrared (MIRI) image is on the right, and it is the first ever to resolve both stars of the binary pair at the center of the nebula.

Image Credit: NASA / ESA /CSA / STScI

Stephen’s Quintet in a New Light

Here’s the image of Stephen’s Quintet that was released as one to the first JWST images yesterday. It’s a false color image assembled from infrared data from the MIRI andNIRSpec instruments.

Image Credit: NASA / ESA / CSA / STScI

Here’s how Hubble sees the same view in visible light.Stephan's_Quintet

Image Credit: STScI

Stephan’s Quintet in the constellation Pegasus is a visual grouping of five galaxies. These galaxies are of interest because of their violent collisions. Four of the five galaxies in Stephan’s Quintet form a physical association, Hickson Compact Group 92, and are involved in a cosmic dance that most likely will end with the galaxies merging.

Microlensing

On 11 June, I posted a link to a YouTube video about how microlensing was used to find a black hole drifting through our galaxy. This animation was made from set of Hubble Space Telescope photos that capture the gravitational effects the black hole. It’s warping of the fabric of space can be measured by the way it warps the light of a background star, an effect called gravitational microlensing. As seen by Hubble, the background star momentarily brightened,  then faded back to normal brightness, as the foreground black hole drifted by.

Image Credit: NASA / ESA / STScI