Ring Around the Cluster
It is difficult to hide a galaxy behind a cluster of galaxies. The closer cluster's gravity will act like a huge lens, pulling images of the distant galaxy around the sides and greatly distorting them. This is just the case observed in the ...
Orion's Horsehead Nebula
The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the black indentation to the red emission nebula seen just to the right of center of the above photograph. The bright star near the center is located in the belt ...
Mercury: A Cratered Inferno
Mercury's surface looks similar to our Moon's. Each is heavily cratered and made of rock. Mercury's diameter is about 4800 km, while the Moon's is slightly less at about 3500 km (compared with about 12,700 km for the Earth). But Mercury is ...
ESO202-G23: Merging Galaxies
SO202-G23 is a colorful mess. It is a collision between two galaxies taking place over hundreds of millions of years. The representative colors give astronomers some idea of what is going on. Visible in this jumble is an active nucleus spewing ...
The Year of Distant Supernovae
Distant supernovae were among topics at the forefront of astronomy during 1998. Two independent groups raced to deploy large telescopes to scan the sky, discovering and analyzing far-off supernovae with the promise of calibrating the geometry of ...
Supernova 1994D and the Unexpected...
Far away, long ago, a star exploded. Supernova 1994D, visible as the bright spot on the lower left, occurred in the outskirts of disk galaxy NGC 4526. Supernova 1994D was not of interest for how different it was, but rather for how similar it ...
A Geminid From Gemini
The Leonid meteor shower was not the only good meteor shower this season. Earlier this month, the annual Geminids meteor shower peaked, featuring as many as 140 meteors per hour from some locations. Geminid meteors can be seen streaking away ...
NEAR to Asteroid Eros
On December 23, the NEAR spacecraft flew by asteroid 433 Eros. NEAR was originally scheduled to brake and orbit Eros, but an unexpected shutdown of its main engine caused this plan to be aborted. NEAR will now be reset and attempt to return to ...
M2-9: Wings of a Butterfly Nebula
Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured above, the stars transform themselves from normal ...
Gamma-Ray Quasar
The bright object in the center of the false color image above is quasar 3C279 viewed in gamma-rays, photons with more than 40 million times the energy of visible light. Like all quasars, 3C279 is a nondescript, faint, star-like object in the ...
