Sunday, November 28, 2010

Broke California

Sometimes, imaging sessions don't work out so well. Unexpected changes in the weather, equipment problems, and even poor planning can bring disaster. Take, for instance, the other night...

I set up in the ObservaRory (my yard) to image Messier 77. I quickly realized, though, that M77 was way too small for my ST80--there's not much to see at that magnification. I wouldn't have wasted my time if I done sufficient research on my target.

Auriga was above the trees, so I decided to try something really ambitious: the Flaming Star Nebula. No good, though. It wasn't nearly dark enough, and even with a 3-minute exposure there wasn't much to see. Again, poor planning on my part.

I've been wanting to image the California Nebula (NGC 1499) for some time. It's a large nebula, from our perspective, but it's also very faint. I figured that if I could get a minimally decent image of the Witch Head Nebula, then I could get the California.

Within a few minutes I was set up and taking 3-minute exposures. It was faint, but I was happy that it showed up at all. Maybe the night wouldn't be a complete loss.

Time was not on my side. For one, the Moon was rising at 10:23 that night, and it was already nearly 9:30 by the time I got everything going. Also, my infant son was asleep and would likely wake sometime between 10:30 and 11:00 to be fed and have his diaper changed. Once everything was set up I went inside to watch a movie with my older son.

I went outside around 11:00 (just as the little one was starting to stir) to check things out, expecting the sequence to be just about done. To my dismay, however, I discovered that the laptop that was controlling the camera had gone into sleep mode due to inactivity. UGGGG!!! (I know that I had disabled the auto sleep mode. How it came to be turned back on again, I have no idea...) The sky was too bright to continue imaging the California Nebula, and I had baby maintenance duties to perform, so I shut everything down.

Upon examining the images later, I discovered that there was an odd blemish--probably something to do with dust and/or dew on the objective lens. I had forgotten to take flats, so I was stuck with it. Add to that the fact that I didn't get nearly as many subs as I wanted...

But, here it is, anyway. Like the real state of California, mine is broke(n), but it's still a pretty nice place:

NGC 1499, the California Nebula. ST80 on Vixen SP. 22x180 at ISO-1600.
The nebula lies approximately 1,500 to 1,800 light years away, and resides in the Orion arm, which is the same spiral arm of the galaxy as the Sun. It is about 100 light years across.

To the south of the nebula is the bright star Xi Persei, also known as Menkib. It is on the right-hand side of this image. Menkib may be providing most of the light that is energizing the nebula

Menkib means "collarbone" in Arabic, and it is part of an old Arabic constellation that includes the nearby Pleiades. Even though Menkib is relatively faint in our skies (apparent magnitude of 3.96), it is actually about 13,500 times brighter than then Sun in the visible spectrum. That makes it the most luminous star that we can see with the naked eye. It appears so dim to us because of its distance and the vast amount of light-absorbing interstellar dust between us.

Menkib is also a "runaway star." It is moving away from us at an unusually high rate of speed (about 20 km/s). Its speed may have been gained from a gravitational encounter with another star, or by the supernova explosion of a previous companion star. Menkib itself is a supernova candidate, and may explode anytime within the next million years.

Friday, November 19, 2010

The Leo Triplet

About 35 million light years away in the Leo constellation lie three galaxies--Messier 65, Messier 66 and NGC 3628. This group is called the Leo Triplet, or the Leo Trio. Each is a spiral galaxy, and each is gravitationally influenced by the other two.

Here is Messier 65. It has a high ratio of old to new stars due to its relatively low quantity of gas and dust. Note the prominent dust lane in the foreground. The star in the middle of the dust lane resides in our own galaxy.

Messier 65

Messier 66 has an unusual shape.  Its spiral arms appear to be bent above the plane of the galaxy, and the nucleus is off-center. This is likely due to its gravitational interaction with its neighbors. Messier 66 is about 95 light years across, which makes it slightly smaller than the Milky Way.

Messier 66
The faintest of the three galaxies is NGC 3628. It is seen edge-on. The outer edges are distorted as a result of the gravitational influences of Messier 65 and Messier 66.

NGC 3628
The Leo Triplet can be easily viewed in a 6-inch telescope (and in some smaller scopes) in clear, dark skies. It is likely that Charles Messier's equipment was not sensitive enough to detect NGC 3628, which explains why it was not cataloged along with its neighbors.

Sunday, November 14, 2010

Looking for Faces in All the Wrong Places

Note:  This is a discussion of the Face on Mars. It will likely make some people angry. I believe that the "face" is a natural feature. This topic has been discussed to death by various individuals on both sides of the argument, but I thought I'd try my hand at it, anyway.

Images are courtesy of the European Space Agency. Yes, I'm using data from an ESA web site to discuss something that NASA did. Go figure.

The human brain is an amazing piece of engineering. Ironically, it is so complex that not even the human mind can't fully comprehend it, but significant progress has been made in decoding some of the brain's mechanical processes.

One of these processes deals with face recognition. Studies have shown that part of the brain's visual processing region, called the fusiform gyrus, is responsible recognizing and categorizing visual information. A specific area in the fusiform gyrus, known as the fusiform face area, seems to be responsible for recognizing human faces. Other studies have shown that this ability is already functioning at birth. Such mechanisms are essential for our survival, and most tend to stick with us throughout our lives.

And that's a good thing. Imagine what life would be like if you couldn't recognize friends, family, or even yourself. Unfortunately, there is such a condition. It's called prosopagnosia, and may involve damage to the fusiform face area.

Conversely, we often recognize faces where there are none. Pareidolia is a phenomenon where we see images and faces in things that are not related to the things we perceive. For example, most of us have recognized the shape of an animal or other thing in a cloud.

This ability has its advantages. It permits us to see through camouflage, pick out faces from a crowd, and produce interesting art.

But, it can easily be carried too far.

Take for example, the infamous Face on Mars.

While taking pictures of potential landing sites in 1976, the Viking 1 probe imaged the Cydonia region of Mars. One of the more intriguing features was a mesa that resembled a human face. As soon as the image became public people began to claim that the image was an artificial construction. It was hard to argue against what the eye was perceiving, though, until NASA was able to get higher resolution images nearly 25 years later.

I thought it might make an interesting exercise to show how the real feature can be mistaken for something that it's not, when the conditions are right.

First, here is the original Viking 1 image from 1976:

Yes, it's small. Actually, I think this is a slightly enlarged version of the original image. The resolution was very low--somewhere in the order of 150 to 300 meters per pixel. The pixels represent two types of things: luminance data, and missing data. Luminance data represents the brightness of the surface being imaged. Combine luminance pixels together and you get a black-and-white image. The missing data is just that: pixels that were lost in transmission.

Below is an image from the Mars Global Surveyor (MGS). This one has been scaled down to save space. A larger version is available here.

Big difference, huh? Well, the resolution of this image is MUCH higher, and the image was taken when the sun was higher in Cydonia's sky. It's still easy to see some parts of the face in the image, but, in my opinion, it certainly doesn't look as much like a face as the Viking 1 image.

For my little exercise, I reduced the MGS image to approximately the same size as the Viking 1 image:

Next, I simulated the shadows from the Viking 1 images by adjusting the contrast:

I thought that the image still had too much detail, so I blurred it a little:

Finally, I attempted to identify the missing pixels on the Viking 1 image and apply them to this image. This gives the face its right "nostril:"

OK, maybe it's not as impressive as the original Viking 1 image, but I think it still proves my point that it is easy to mistake one thing for another.

And this phenomenon isn't limited to just the "I-know-what-I-saw" and the I Want to Believe crowds. Famed astronomer Percival Lowell was convinced that there were canals--and therefore an advanced civilization--on Mars. And more recently one of my favorite astronomers thought he saw the ghost of Lenin on his shower curtain.  (OK, not really, but it sounds funnier that way.)

Still, despite the evidence, some people cling to the idea that the Face on Mars was made by some intelligent force. I admit its more fun to believe in space aliens, fairies, and that Andy Kaufman and Elvis are still alive. But, there are times when we need to face facts and move forward--and hanging onto a fantasy doesn't do anyone any good.

I think, instead, that we should focus our energy on finding out who or what created these interesting Martian features:

Tuesday, November 9, 2010

Messier 33

Messier 33, also called the "Triangulum Galaxy" or "Triangulum Pinwheel," is located in the Triangulum constellation. It is barely visible to the naked eye in clear, dark skies. It appears as a circular fuzzy patch in a small telescope.

M33 is part of the Local Group, which is the group of at least 30 or so galaxies that include our Milky Way and the Andromeda Galaxy. It is located about 3 million light years away, which is relatively close in a galactic sense. It's proximity makes it an ideal target for study by astronomers.

This image is composed of 21 2-minute sub-frames taken by a Canon EOS Rebel XS with the ST80 on a Vixen SP mount.

Messier 33, The Triangulum Galaxy

Monday, November 1, 2010


I've been trying to photograph lightning for quite a while.  It's pretty tough to get good shots.  It takes patience, and a good deal of luck.  So far my efforts have been mediocre at best.

This evening I got my best shots so far.  While our neighbors in Montgomery County were getting pounded by powerful thunderstorms, I was taking snapshots of all of the excitement from my front yard.  Below are the best two shots of the series.  They are 5-second exposures, taken at ISO-1600.