The Andromeda Galaxy

If you’ve ever seen a picture of another galaxy, odds are that it was of this one, the Andromeda galaxy, also known as M31. At a distance of 2.54 million light years from us, it is closer and hence appears larger than any other galaxy (apart from the two Magellanic Clouds in the southern hemisphere that are small satellites of our Milky Way). And it is on a collision course with us and will collide with our Milky Way in about four billion years.

Open Clusters

Scattered mostly along the Milky Way are stellar groupings called open clusters, randomly shaped families of mostly young, hot stars that are all gravitationally bound to each other. Most stars are born in such clusters, containing anything between perhaps twenty to a few thousand stars. All of the stars in a given cluster are about the same age, having formed together from the same nebula.

Globular Clusters

Here are four representative Globular clusters. Globular Clusters are gigantic spherical agglomerations of stars that surround the nucleus of our Milky Way galaxy. Each globular cluster from hundreds of thousands to several million stars, and astronomers believe that the stars is most globular clusters are among the oldest stars in existance, perhaps as much as 10 billion years old.

A New Supernova in Nearby Galaxy M61

This supernova was discovered on May 6. It is expected to continue to brighten for several days before fading away over several weeks.

Two Face-on Spiral Galaxies - A Study in Contrasts

M94 is a face-on spiral galaxy whose spiral arms hug the middle and wind very tightly into the core. It is sometimes called the Cat’s Eye galaxy or the or Croc’s Eye Galaxy. It is about 16 million light years from the Earth. Around the brilliant circular disk is a ring of active star-forming regions, revealed in astrophotography as blue young star clusters. This artifact delineates it from the faded outer ring of an older yellowish stellar population.

Comet C/2019 Y4 ATLAS

Comet C/2019 Y4 ATLAS has been a big disappointment. It was discovered just four months ago, on December 28, 2019. Initially it brightened much more quickly than expected, and there were hopes that it might reach naked-eye visibility in late May when it will pass closest to the sun and to the earth. However its nucleus was observed to fragment by early April, and as a result it started getting dimmer instead of brighter. You can see pictures of the fragments taken by the Hubble Space Telescope by clicking on this link.

The Sombrero Galaxy

The Sombrero Galaxy (also known as M104) is a lenticular galaxy about 31.1 million light-years) from Earth. The galaxy has a diameter of approximately 30% the size of the Milky Way. It has a bright nucleus, an unusually large central bulge, and a prominent dust lane in its inclined disk. The dark dust lane and the bulge give this galaxy the appearance of a sombrero hat. Its large bulge, its central supermassive black hole, and its dust lane all attract the attention of professional astronomers.

The Leo Triplet - Three Galaxies

The Leo Triplet is an interesting group of three mutually interacting galaxies that are often observed and photographed within a single field of view. The Leo Triplet includes spiral galaxies M65 (lower right), M66 (lower left), and NGC 3628 (upper left). This group of galaxies is found in the constellation Leo, all of them are about 35 million light years from the earth.

Galaxy M83

Here is a face-on view of the barred spiral galaxy Messier 83, the southern pinwheel galaxy. (It is believed that our own Milky Way galaxy would look very much like M83 if we could view it from outside, although the Milky Way is about twice as large as M83 is.) Notice the bright central nucleus, the well-formed spiral arms, the central bar, and the dark dust lanes.

The Horsehead Nebula

The Horsehead Nebula consists of a cloud of ionized gas lit from within by young, hot stars; a dark cloud containing interstellar dust lies immediately in front. The dust absorbs the light from part of the ionized cloud. A portion of this dark cloud has a shape somewhat resembling a horse’s head. The nebula is located 1,300 light-years from the Sun.