Sunday, January 30, 2011
Lightning
A Big Scary Thunderstorm--complete with heavy rain, lightning and hail--passed over us this evening. Before the rain and hail started, though, I managed to get a few pictures of the lightning from the relative safety of my front door.
Sunday, January 2, 2011
Horsehead and Flame Nebulae
I'm still trying to learn the capabilities of my little imaging setup. The ST80 is an amazing little telescope, especially considering that it's only an achromat. One of the things that I really like about it is that it has a wide field of view, which means that it is possible to see or image fairly large areas of the sky.
Here is an image of several nebulae around the star Alnitak (Zeta Orionis). Alnitak is the easternmost star in the Belt of Orion. Three prominent nebulae in this image are the Flame Nebula, the Horsehead Nebula, and IC 434. Several smaller reflection nebulae dot the area.
The star Sigma Orionis is located at the top of the image on the right. This star is visible to the naked eye in most locations. It is located south of Alnitak.
The Horsehead Nebula is a dark nebula, which is an opaque cloud of dust and gas. Located behind it is emission nebula IC 434. The Flame Nebula is being lit up by Alnitak and stars buried within the nebula.
Here is an image of this same area that I made using Sam Houston State University's Takahashi Epsilon-200:
Here is an image of several nebulae around the star Alnitak (Zeta Orionis). Alnitak is the easternmost star in the Belt of Orion. Three prominent nebulae in this image are the Flame Nebula, the Horsehead Nebula, and IC 434. Several smaller reflection nebulae dot the area.
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| Horsehead and Flame Nebulae, ST80 on Vixen SP, 12x180 |
The Horsehead Nebula is a dark nebula, which is an opaque cloud of dust and gas. Located behind it is emission nebula IC 434. The Flame Nebula is being lit up by Alnitak and stars buried within the nebula.
Here is an image of this same area that I made using Sam Houston State University's Takahashi Epsilon-200:
Messier 79
The constellation Lepus, the hare, is located south of the Orion constellation. In some stories, Lepus is being flushed from the grass by Orion's hunting dogs, Sirius and Procyon. Located in the southern part of Lepus is a very unusual sight for this area of the sky: a globular cluster. Most globular clusters are located closer to the core of the Milky Way. There is evidence that suggests that M79 was stolen by the Milky Way from the Canis Major Dwarf galaxy.
Messier 79 is about 40,000 light years away, and is about 118 light years across.
Messier 79 is about 40,000 light years away, and is about 118 light years across.
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| Messier 79, ST80 on Vixen SP, 33x60 |
Saturday, December 18, 2010
2010 Geminid Meteor Shower
No, we're not going to warp. This is a composite image generated from several sub-frames taken of the Geminid Meteor Shower this past December 14th. I set up the camera on the Vixen SP and pointed it at Gemini. Out of 276 30-second exposures, meteors appeared on only six images.
Meteor showers usually occur when the Earth moves through a cloud of particles that have been cast off by a comet. The Geminids were assumed to be from a comet, but no comet was known that could have produced them. However, In 1983 asteroid 3200 Phaethon was discovered and shortly thereafter identified as the source. It may be a chunk that was broken off of a larger asteroid, Pallas. The particles that we see as meteors may be debris left over from a collision or other breakup event.
The shower was actually quite active--despite the lackluster appearance of meteors in the image above. I stopped counting fairly early on, but saw dozens over the course of the night.
Meteors can appear anywhere in the sky, but their trails point back to a small area called the radiant. This is the point in the sky that corresponds to the direction in which the Earth is moving and plowing through the debris field.
The two bright stars near the center of the image are Castor (left) and Pollux (right). The radiant is located just above Castor. Gemini extends to the upper-right of the image. The cluster of stars to the lower-right is Messier 44, the Beehive Cluster.
Meteor showers usually occur when the Earth moves through a cloud of particles that have been cast off by a comet. The Geminids were assumed to be from a comet, but no comet was known that could have produced them. However, In 1983 asteroid 3200 Phaethon was discovered and shortly thereafter identified as the source. It may be a chunk that was broken off of a larger asteroid, Pallas. The particles that we see as meteors may be debris left over from a collision or other breakup event.
The shower was actually quite active--despite the lackluster appearance of meteors in the image above. I stopped counting fairly early on, but saw dozens over the course of the night.
Meteors can appear anywhere in the sky, but their trails point back to a small area called the radiant. This is the point in the sky that corresponds to the direction in which the Earth is moving and plowing through the debris field.
The two bright stars near the center of the image are Castor (left) and Pollux (right). The radiant is located just above Castor. Gemini extends to the upper-right of the image. The cluster of stars to the lower-right is Messier 44, the Beehive Cluster.
Thursday, December 2, 2010
Rosette Nebula
The Rosette Nebula (Caldwell 49) lies in the constellation Monoceros, the Unicorn. It is a faint emission nebula that surrounds open cluster NGC 2244 (Caldwell 50). Both the nebula and the cluster lie between 5,000 and 5,200 light years away. At that distance, the Rosette Nebula is about 100 to 130 light years in diameter. The visible part of the nebula in the image below covers an area slightly larger than the diameter of the full moon, but is so faint that it requires either a very large telescope to see it visually, or long-exposure images. The Rosette's name comes from the nebula's resemblance to a decorative emblem.
The stars of NGC 2244 are young--only about four million years old--and extremely hot. The pressure of their stellar winds is clearing out a space within the nebula. This action also compresses nebular gas along the outside edges of the cleared space, which triggers additional star formation.
The Rosette Nebula is the most visible part of the much larger Rosette Molecular Cloud.
The stars of NGC 2244 are young--only about four million years old--and extremely hot. The pressure of their stellar winds is clearing out a space within the nebula. This action also compresses nebular gas along the outside edges of the cleared space, which triggers additional star formation.
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| Caldwell 49 (Rosette Nebula), ST80 on Vixen SP, 17x180 |
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:
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.
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:
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| NGC 1499, the California Nebula. ST80 on Vixen SP. 22x180 at ISO-1600. |
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 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.
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.
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.
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.
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| 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.
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| Messier 66 |
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| NGC 3628 |
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