Tycho’s Supernova

In 1572, Danish astronomer Tycho Brahe was among those who reported a new bright object in the constellation Cassiopeia. We now know that Tycho’s new star was not new at all. It was a supernova, a stellar explosion so bright that it can outshine the light from rest of the galaxy. This particular supernova was a Type Ia, which occurs when a white dwarf star pulls material from, or merges with, a nearby companion star until a violent explosion is triggered. The white dwarf star is obliterated, sending its debris hurtling into space.

This false color image of the remnant of Tycho’s supernova combines from the Chandra X-ray Observatory with optical data from the Digitized Sky Survey. It uses date from two narrow ranges of X-ray energies to isolate material (silicon, colored red) moving away from Earth, and moving towards us (also silicon, colored blue). The other colors in the image (yellow, green, blue-green, orange and purple) show a broad range of different energies and elements, and a mixture of directions of motion.

Image Credit: X-ray—NASA / CXC / RIKEN & GSFC / T. Sato et al; Optical: DSS

NGC 613

A spiral galaxy’s brights and darksNGC 613 is a barred spiral galaxy about 65 million light-years away in the constellation of The Sculptor. It’s core looks bright and uniformly white in this image as a result of the combined light shining from the high concentration of stars packed into the core, but a massive black hole lurks at the center of this brilliance. Its mass is estimated at about 10 times that of the Milky Way’s supermassive black hole, and it is consuming stars, gas, and dust. As matter descends into the black hole’s, it radiates energy, but when looking at the galaxy in the optical and infrared wavelengths used to take this image, there is no trace of its dark heart.

Image Credit: ESA / NASA

A Bipolar Nebula

PN Hb 12A bipolar nebula, such as PN Hb 12 shown here, is not one that is off its meds. It’s a distinctive type of nebular formation characterized by an axially symmetric bi-lobed appearance.

The exact cause of this nebular structure is not known, it may be related to a physical process in which a star ejects highly energetic streams of outflow along both poles which may then collide with material surrounding the star, perhaps stellar dust or shells of matter thrown off in a prior supernova event.

Image Credit: NASA

The Medusa Merger

The Medusa Merger (aka NGC 4194) is a pair of interacting galaxies in the constellation Ursa Major. As one galaxy has consumed a smaller gas-rich system, throwing out streams of stars and dust into space, which resemble the writhing snakes that Medusa, a monster in Greek mythology famously had on her head in place of hair. Its gas-rich central region, the Eye of Medusa, is an area of extremely intense star formation.

Image Credit: NASA / ESA