The Middle Star in the Sword

Orion NebulaThe Orion Nebula (also known as Messier 42, M42, or NGC 1976) is one of the brightest nebulae, and is visible to the naked eye even in areas affected by minor light pollution. It is seen as the middle “star” in the sword of Orion, the three stars located below Orion’s Belt. The “star” appears fuzzy to sharp-eyed observers, and its nebulosity is obvious through binoculars or a small telescope.

Image Credit: NASA

A Lenticular Seyfert Galaxy

NGC 5283 is a lenticular galaxy, and like about 10 percent of all galaxies, it’s also a Seyfert galaxy with and active galactic nucleus (AGN). An AGN is an extremely bright region at the heart of a galaxy around its supermassive black hole. When dust and gas fall into the black hole, the matter heats up and emits light across the electromagnetic spectrum. Some AGNs emit so much radiation they outshine their host galaxies. Seyfert galaxies differ from other galaxies with AGNs because the galaxy itself is clearly visible.

Image Credit: NASA / ESA / A. Barth (University of California – Irvine) / M. Revalski (STScI)
Processing: Gladys Kober (NAS A/ Catholic University of America)

A Foreground Star and a Background Galaxy

The galaxy NGC 7250 should dominate this image. It has bright bursts of star formation and recorded supernova explosions, but it fades into the background next to the bright star hogging the limelight next to it.

That bright star is named TYC 3203-450-1. It’s located in the constellation of Lacerta (The Lizard). The star is much closer than NGC 7250 which how it is able to outshine a whole galaxy. Astronomers studying distant objects call such stars “foreground stars,” and they are often not very happy about them. Their bright light contaminates the fainter light from more distant and interesting objects they actually want to study.

TYC 3203-450-1 is million times closer than NGC 7250.

Image Credit: NASA / ESA

Warped Galaxies

ARP81This distorted pair of galaxies is called Arp 81. About 100 million years ago, they had a close encounter, and the havoc wreaked by their mutual gravitational interaction resulted ing twisted streams of gas and dust, a chaos of massive star formation, and a tidal tail of debris stretching for a couple of hundred thousand light-years. NGC 6622 (left) and NGC 6621(right) are more of less equal in size. They are destined to merge into one larger galaxy in the distant future, after a mating dance of repeated approaches. The galaxies are 280,000,000 light-years away in the constellation Draco.

Image Credit: NASA

M87 in 3D

This 3D model of elliptical galaxy M87 was created using a Hubble Space Telescope photo. The grid is overlayed to trace out its three-dimensional shape which was derived from observations made with the Hubble and Keck telescopes. The galaxy is too far away for earth-based or orbiting telescopes to employ stereoscopic vision, so observations of the motion of stars around the center of M87 were used to construct this three-dimensional view of how stars are distributed within the galaxy.

Video Credits—
Animation: NASA / ESA / Joseph Olmsted (STScI)
3D Model: Frank Summers (STScI)

A Light Within a Dark Cloud

RNO91A very young star is being born in the dark cloud LDN 43, a massive aggregation of gas, dust, and ices, a bit more than 500 light-years away in the constellation of Ophiuchus (The Serpent Bearer). Dust and gas float in space, and as gravity pulls the matter together, some clumps grown to form stars

This newborn star is hidden from direct view. We can only see it’s light reflected onto the plumes of the dark cloud. It’s be cataloged as RNO 91. It’s a pre-main sequence star. It has not yet started burning hydrogen in its core, so the energy that causes RNO 91 to shine comes from gravitational contraction. As the star is compressed by its own weight, it will eventually reach a critical mass, its hydrogen will begin to undergo the same fusion process that drives our Sun, and RNO 91 will become an adult star. However, the adolescent star is still bright enough to shine and generate powerful stellar winds, intense X-rays, and radio emission.

RNO 91 is a variable star with about half the mass of the Sun. A dusty, icy disk surrounds it, stretching out to over 1,700 times the distance from Earth to the Sun. It is possible that this disk may host protoplanets and may evolve into a fully-fledged planetary system.

Image Credit: NASA

Hubble v. JWST

These two images are of the same part of the sky. The image on the left is from the original Hubble Ultra Deep Field observation. JWST’s Near-Infrared Camera took the image on the right. Hubble’s observation with its Wide Field Camera 3, required an exposure time of 11.3 days. The JWST image only took 0.83 days. Several areas within the Webb image reveal previously invisible, red galaxies. You can download the full resolution from the Space Telescope Science Institute.

Image Credit: NASA / ESA / CSA / Joseph DePasquale (STScI).

Zooming into Cas A

This video zooms in to a JWST view of Cassiopeia A (Cas A), a supernova remnant located about 11,000 light-years away.

Video Credits: NASA / ESA / CSA / D. Milisavljevic (Purdue University) / T. Temim (Princeton University) ‘ I. De Looze (UGent) ‘ J. DePasquale (STScI) / ESA/Hubble / E. Slawik, N. Risinger, D. de Martin, N. Bartmann, and M. Zimani (ESA/Webb) Music Credit: Tonelabs – The Red North (
Creative Commons License

Blue Straggler Stars

M53 (aka NGC 5024) is one of 250 or so globular clusters still surviving in our Galaxy. Most of the stars in M53 are older and redder than our Sun, but some to its stars appear to be bluer and younger. These apparently young stars seem to contradict the idea that all the stars in M53 should have formed around the same time, and these “blue stragglers” are unusually common in M53. They are now thought to be old stars rejuvenated by matter falling in from a binary star companion. M53 is visible with a binoculars when looking toward the constellation of Coma Berenices.

M53 is one of the furthest globular clusters from the center of our Galaxy. It contains over 250,000 stars. If our Solar System were part of M53, the night sky would glow like a jewel box of bright stars.

Image Credit: NASA

Messier 55

This image shows just a portion of Messier M55. The smaller, ground-based image (lower left) taken by the Digital Sky Survey illustrates an area of Messier 55 that Hubble observed. The globular cluster is about 20,000 light-years away and is about 100 light-years in diameter. It contains an estimated 100,000 stars with 55 variable stars whose brightness changes. The cluster as a whole appears spherical because the stars’ intense gravitational attraction pulls them together.

Image Credits: NASA / ESA / A. Sarajedini (Florida Atlantic University) / M. Libralato (STScI, ESA, JWST) / and Digital Sky Survey
Image Processing: Gladys Kober

An Irregular Dwarf

The mysteries of UGC 8201The galaxy UGC 8201 is classified as a dwarf irregular galaxy because of its small size and chaotic structure. It’s a bit less than15 million light-years away in the constellation of Draco (the Dragon). As with most dwarf galaxies, it is a member of a larger group of galaxies, in this case, the M81 galaxy group. This group is one of the nearby neighbors to the Local Group of galaxies which contains our galaxy, the Milky Way.

Image Credit: ESA / NASA