Sunday, April 24, 2011

M81, M82 and friends

Sometimes things don't work out as planned. For example, a couple of months ago I wanted to see how M81/M82 would look in my ST80. I took a test shot and it looked promising; so, I started an imaging series and went inside the house.

Later, a check on the series revealed that things were not going well.  The alignment was off. Perhaps I had bumped the mount without realizing it. For whatever reason, only the test image turned out halfway decent. The rest had significant star trailing.

I recently took a closer look at the series, salvaged the best ones, and applied a star rounding filter to them. The results weren't spectacular, by any means, but with a little more processing and a few tricks I managed to throw together a wide-angle view of the area around M81/M82:

Messiers 81 and 82 and friends; ST80 on Vixen SP; 8x180
This version labels the brighter galaxies, as well as a few of the dimmer ones that I was able to find:

Tuesday, April 19, 2011

Heart of the Scorpion

Antares is a supergiant star in the constellation Scorpius. It is nearly 300 million miles across, which is larger than the orbit of Mars! Antares is sometimes called the "Heart of the Scorpion."

The area in the sky around Antares is full of exciting objects. I imaged a small part of it while waiting for M8/M20/M21 to rise one morning. I took only a few images, but after heavy image processing I came up with the following:

Antares, Messier 4, NGC 6144 and IC 4605; ST80 on Vixen SP; 6x180
Antares is the yellow star at the bottom of the image. It appears orange to the naked eye. The yellow color here is due to the fact that the star is overexposed, and the camera is less sensitive to the red part of the spectrum.

Clouds of interstellar gas and dust fill the area, adding unusual patterns and colors to the scene.

Messier 4 is the large globular cluster at the top. It is about 7,200 light years away and is one of the closest globular clusters to Earth. Messier 4 is also called the Cat's Eye cluster because of the conspicuous bar structure across the middle.

Globular cluster NGC 6144 is located to the upper-left of Antares. It is about 33,000 light years away.

The blue reflection nebula IC 4605 is in the lower-left corner.

I plan on revisiting this and the surrounding area one day. There is a lot more to see!

Friday, April 15, 2011

A Lagoon, a three-lobed cloud, and a bunch of stars!

Sagittarius is one of my favorite constellations. It is full of interesting things to see: open clusters, globular clusters, nebulae and the Sagittarius Star Cloud. It is also the location of the galactic center.

The image below is a composite of two separate shots. The large nebula on the right is Messier 8, the Lagoon Nebula. It is a bright star forming region, and is visible to the naked eye even in somewhat light polluted skies. The red glow comes from hydrogen gas that is being energized by ultraviolet radiation from the stars that are forming within the nebula. The process that causes this is similar to the process that causes fluorescent lights to glow.

The small nebula near the upper-left is Messier 20, the Trifid Nebula. The same process that causes the Lagoon Nebula to glow red is at work in the red portion of the Trifid. The blue color comes from starlight that is being reflected off of gas and dust. Trifid means "divided into three parts," in reference to the dark lanes that divide the red portion.

Messier 21 is the open cluster on the left side of the image.  And, located in the lower-right corner is globular cluster NGC 6544.

Messiers 8, 20, 21, and NGC 6544 in Sagittarius; ST80 on Vixen SP

Wednesday, April 13, 2011

Messier 13, the Great Globular Cluster in Hercules

Messier 13, also known as the Great Globular Cluster in Hercules, is the brightest globular cluster in the northern hemisphere. It is a little over 25,000 light years away, about 145 light years in diameter, and contains hundreds of thousands of stars. M13 is visible to the naked eye on dark, clear nights away from city lights.

Messier 13; ST80 on Vixen SP; 16x120
Spiral galaxy NGC 6207 is visible near the lower-left corner of the image. Also visible in this image (barely) is spiral galaxy IC 4617. It is located about halfway between the center of M13 and NGC 6207, next to a pair of stars.

Messier 13 was chosen as the target for the Arecibo message of 1974. The message was a single (non-repeated) transmission of binary data that, when decoded, provided various details about Earth and humankind. It was not meant to be a serious attempt at contacting extraterrestrial life, though. Instead, the message was intended to demonstrate the capabilities of the newly refurbished Arecibo radio telescope. I am sure that we can all take comfort in that fact when some alien civilization intercepts the message and sends a fleet of warships to exterminate humanity.

This image is dedicated to Jeff the (Former) Programmer. I'm gonna miss working with ya!

Addendum: Jeff isn't dead or anything. He recently resigned from where I work.

Monday, April 11, 2011

M104, the Sombrero Galaxy

Messier 104 is an unusual galaxy in the constellation Virgo. The prominent dust lane, along with its bright central bulge, have earned it the nickname, the Sombrero Galaxy.

The dust lane is actually a ring. Most of the galaxy's star formation occurs there.

Messier 104, the Sombrero Galaxy; Epsilon-200 on NJP Mount; 7x120
The Hubble Space Telescope was used to take a fantastically detailed image of Messier 104.

Messier 81 and Messier 82

These two galaxies, Messier 81 and Messier 82, are considered the finest "showpiece" galaxies in the northern hemisphere. Located in the constellation Ursa Major, both galaxies were discovered by Johann Elert Bode in 1774. The larger galaxy, Messier 81, is a spiral galaxy and is often referred to as "Bode's Galaxy," or "Bode's Nebula." Messier cataloged both objects in 1781.

Messier 82 is an unusual cigar-shaped galaxy. It is usually classified as an irregular galaxy, but a study in 2005 discovered evidence of spiral arms. Tidal forces from Messier 81 have compressed gas and dust in Messier 81's core, which has triggered a large amount of star formation. As a result, it is classified as a starburst galaxy. Messier 81 and Messier 82 are moving toward each other and will eventually merge into a single galaxy.

Messier 81 and Messier 82, Epsilon-200 on NJP mount, 14x240
This image was the first that I've taken with the Epsilon-200 in several months. The tracking issues on the NJP have been largely resolved, so I am able to take longer exposures. Longer exposures generate more noise in the images, though, and the improved tracking means that objects in the field of view move very little from one exposure to the next. As a result, the stacking software tends to see hot pixels (stuck sub-pixels) as "signal" instead of "noise."