Date: 3 June 2007 U.T.
Time: 3:00 - 5:00 U.T.
Telescope: 13cm refractor
Magnifications: 35x, 90x, 170x, 240x
Filters: #56 and #58 Green (for Venus only)
Seeing: Good
Transparency: Bright and darkening twilight
After many cloudy or otherwise missed nights everything fell into place for a good evening. The telescope was set up on on an equatorial mount with an electric RA drive. The motorized tracking simplified sharing the view with two guests.
Venus was our first target, and for a long while our only target. The seeing was very steady with the refractor -- one of the benefits to using a relatively small telescope. The planet's sharply defined quarter (or 'half-moon') phase was easily visible to everyone present.
The green filters helped cut down the brightness of the brilliant, white planet to a more tolerable level. We took turns studying the planet at 90x. Through the use of questions and answers, it looked like the guests may have been able to perceive some of the subtle markings in the Venusian atmosphere.
Eventually the sky darkened enough for the younger guest to spot Saturn in the twilight sky. We shared views at 35x and gradually worked our way up to 240x. Titan was immediately noticed near the ringed planet. After the sky had darkened a bit more we saw three more of Saturn's moons. The two moons between Titan and the planet, one above the other, were later identified as Tethys (to the north) and Rhea (south of Tethys). Just off the north-following limb of the planet was Dione.
At the higher magnifications the ring was visible in front of the planet. The guests also noticed Saturn's South Equatorial Belt (SEB). Cassini's Division presented a challenge for the guests, but they eventually succeeded in seeing this division between Saturn's A and B rings -- at least on one side of the ring system. The shadow of the planet on the ring system proved to be a bit more of a challenge for the guests.
After Saturn we took a look at the globular cluster, M13 in Hercules. Next was the Ring Nebula (M57) in Lyra. The final object was Albireo (Beta Cygni) -- one of the northern hemisphere's "showpiece" double stars.
Twilight had still not quite ended by the sessions end. Nevertheless, part of the summer Milky Way was seen. We also saw at least one meteor, an airplane and at least one satellite.
Showing posts with label Nebulae. Show all posts
Showing posts with label Nebulae. Show all posts
03 June 2007
13 April 2007
A Brief Binocular Session
Date: 13 April 2007 U.T.
Time: 4:00 - 4:30 U.T.
Binoculars: 20x80 (hand-held)
Seeing: Good
NELM: 6.4 (or better)
Temperature: +29 F (-2 C)
Three relatively bright non-Messier objects were targeted this evening. The first was NGC 2403. This galaxy was very easy to see with the large binoculars. It looked like a small, distinct patch of nebulosity and was more readily visible than many of the Messier galaxies.
Next was NGC 3242 "The Ghost of Jupiter". This object is a small, but very bright planetary nebula. Through the binoculars it resembled a slightly bloated, slightly fuzzy star. The detailed charts in the Uranometria Atlas allowed for easy identification via the surrounding star field.
Last on my list was NGC 4565 "The Needle Galaxy". This well-known, edge-on, spiral galaxy was visible in the binoculars as a small, faint, elongated glow with a somewhat brighter middle.
For whatever reason, I found myself looking in the vicinity of M81 with the unaided eye. I noted the nearby star pattern as plotted on atlas charts. All of the nearby stars plotted in the Cambridge Star Atlas (2nd edition) were visible to the unaided eye. In particular, I noted 24 Ursae Majoris and the unlabeled star between 24 and M81. At times I suspected a tiny, faint glow at the exact spot where M81 was supposed to be.
I'm not positive that I saw M81 with the unaided eye on this evening; but I'll try to remember to look for this relatively bright galaxy from time to time (with the unaided eye) when conditions are favorable.
Time: 4:00 - 4:30 U.T.
Binoculars: 20x80 (hand-held)
Seeing: Good
NELM: 6.4 (or better)
Temperature: +29 F (-2 C)
Three relatively bright non-Messier objects were targeted this evening. The first was NGC 2403. This galaxy was very easy to see with the large binoculars. It looked like a small, distinct patch of nebulosity and was more readily visible than many of the Messier galaxies.
Next was NGC 3242 "The Ghost of Jupiter". This object is a small, but very bright planetary nebula. Through the binoculars it resembled a slightly bloated, slightly fuzzy star. The detailed charts in the Uranometria Atlas allowed for easy identification via the surrounding star field.
Last on my list was NGC 4565 "The Needle Galaxy". This well-known, edge-on, spiral galaxy was visible in the binoculars as a small, faint, elongated glow with a somewhat brighter middle.
For whatever reason, I found myself looking in the vicinity of M81 with the unaided eye. I noted the nearby star pattern as plotted on atlas charts. All of the nearby stars plotted in the Cambridge Star Atlas (2nd edition) were visible to the unaided eye. In particular, I noted 24 Ursae Majoris and the unlabeled star between 24 and M81. At times I suspected a tiny, faint glow at the exact spot where M81 was supposed to be.
I'm not positive that I saw M81 with the unaided eye on this evening; but I'll try to remember to look for this relatively bright galaxy from time to time (with the unaided eye) when conditions are favorable.
07 March 2007
M 78
Date: 07 March 2007 U.T.
Time: 2:34 - 2:54 U.T.
Telescope: 30cm Newtonian
Magnification: 90x
Seeing: Good
NELM: 6.5
Temperature: +43 F (+6 C)
M78 is a bright patch of nebulosity in Orion. Two bright stars and one fainter star were seen within the nebulosity. A fourth star was briefly suspected, but not recorded. The northwestern edge of the nebula was brightest and best defined. The rest of the nebula fanned out south-southeastward like a short, but very wide cometary tail.
Nearby, just northwest of M78 was a fainter, elongated patch of nebulosity, NGC 2067. Oddly enough, I noticed a dark lane between the two nebulous patches before I realized that there had to be a second patch of nebulosity to complete the appearance of a dark lane. This nebula came as a surprise to me. If I had seen it before I had forgotten about it.
A third patch of nebulosity, NGC 2071 was easily seen surrounding a bright star in the same field of view north-northeast of M78.
After looking up M78 in various books and atlases I noted a fourth patch of nebulosity, NGC 2064 southwest of M78. I failed to notice this patch at the telescope; but now that I know it's there I can look for it next time.
Time: 2:34 - 2:54 U.T.
Telescope: 30cm Newtonian
Magnification: 90x
Seeing: Good
NELM: 6.5
Temperature: +43 F (+6 C)
M78 is a bright patch of nebulosity in Orion. Two bright stars and one fainter star were seen within the nebulosity. A fourth star was briefly suspected, but not recorded. The northwestern edge of the nebula was brightest and best defined. The rest of the nebula fanned out south-southeastward like a short, but very wide cometary tail.
Nearby, just northwest of M78 was a fainter, elongated patch of nebulosity, NGC 2067. Oddly enough, I noticed a dark lane between the two nebulous patches before I realized that there had to be a second patch of nebulosity to complete the appearance of a dark lane. This nebula came as a surprise to me. If I had seen it before I had forgotten about it.
A third patch of nebulosity, NGC 2071 was easily seen surrounding a bright star in the same field of view north-northeast of M78.
After looking up M78 in various books and atlases I noted a fourth patch of nebulosity, NGC 2064 southwest of M78. I failed to notice this patch at the telescope; but now that I know it's there I can look for it next time.
20 February 2007
The Great Orion Nebula
Date: 20 February 2007 U.T.
Time: 4:20 - 4:50 U.T.
Telescope: 30cm Newtonian
Magnifications: 61x and 155x
NELM: 6.5
Seeing: Poor
Temperature: +24 F (-4 C)
The Great Orion Nebula, also known as M42 is one of the brightest and most beautiful nebulae in the night sky! This large nebula practically fills the field of view at 61x. In its brightest regions it's possible for some people to see color. I noted a weak greenish glow in the brightest parts of the nebula and a hint of red in some of the other areas.
Within the brightest part of M42 is a tight group of four stars known as the Trapezium. At 155x I was able to see a fifth star in the Trapezium without much difficulty. A sixth star was more difficult due to the poor seeing conditions; but it was occasionally suspected near the glow of the brightest member of the 'big four.' On a good night I've seen all six stars with ease while using a considerably smaller (13cm) telescope.
M42 is a very irregularly shaped nebula. It has many curves and regions of widely varying brightness. I used the low magnification of 61x in order to be able to see the entire nebula at once; but it's well worth the time to study individual parts under higher magnification.
M43 shares the field with M42. It's much smaller in size, has a semi-bright star within it, and has the shape of a fat comma. While having separate entrees in the Messier Catalog, M42 and M43 are parts of the same nebula complex.
Before ending the session I swung the scope around to Saturn for a quick look at one of our solar system's real show-pieces. Saturn is always a joy to behold!
Even if I weren't too tired to continue observing I would have had to quite soon due to increasing clouds. As I was bringing the scope, etc. back inside more and more stars were disappearing behind the thickening clouds.
Time: 4:20 - 4:50 U.T.
Telescope: 30cm Newtonian
Magnifications: 61x and 155x
NELM: 6.5
Seeing: Poor
Temperature: +24 F (-4 C)
The Great Orion Nebula, also known as M42 is one of the brightest and most beautiful nebulae in the night sky! This large nebula practically fills the field of view at 61x. In its brightest regions it's possible for some people to see color. I noted a weak greenish glow in the brightest parts of the nebula and a hint of red in some of the other areas.
Within the brightest part of M42 is a tight group of four stars known as the Trapezium. At 155x I was able to see a fifth star in the Trapezium without much difficulty. A sixth star was more difficult due to the poor seeing conditions; but it was occasionally suspected near the glow of the brightest member of the 'big four.' On a good night I've seen all six stars with ease while using a considerably smaller (13cm) telescope.
M42 is a very irregularly shaped nebula. It has many curves and regions of widely varying brightness. I used the low magnification of 61x in order to be able to see the entire nebula at once; but it's well worth the time to study individual parts under higher magnification.
M43 shares the field with M42. It's much smaller in size, has a semi-bright star within it, and has the shape of a fat comma. While having separate entrees in the Messier Catalog, M42 and M43 are parts of the same nebula complex.
Before ending the session I swung the scope around to Saturn for a quick look at one of our solar system's real show-pieces. Saturn is always a joy to behold!
Even if I weren't too tired to continue observing I would have had to quite soon due to increasing clouds. As I was bringing the scope, etc. back inside more and more stars were disappearing behind the thickening clouds.
Horsehead Nebula, etc.
Date: 20 February 2007 U.T.
Time: 4:10 U.T.
Telescope: 30cm Newtonian
Magnification: 61x
Filter: UltraBlock
NELM: 6.5
Seeing: Poor
Temperature: +25 F (-4 C)
I started out without using the above mentioned filter. NGC 2024 (also known as the Flame Nebula and Tank Track Nebula) was visible near Zeta Orionis. This nebula has a prominent dark lane running through it.
After shifting the telescope slightly to the south, Zeta Orionis left the field of view. The small, bright nebula NGC 2023 was now easily visible surrounding a star.
The next logical step was to look for IC 434 (a faint 'bright' nebula) and the dark notch within it known as B33 -- the Horsehead Nebula. These objects were visible with difficulty. IC 434 was only slightly brighter than the background sky. The Horsehead Nebula has a reputation for being a particularly difficult object to see visually without the use of a specialized (H-Beta) filter. In order to successfully see this object without a filter one must observe from a dark location that's free from the glow of city lights.
I don't have an H-Beta filter; but I do have an UltraBlock filter. The UltraBlock is a multi-layered, interference filter that selectively blocks the wavelengths of some of the more common man-made light sources (as well as some of the natural sky glow) while allowing other wavelengths to freely pass through. I screwed the UltraBlock filter into the eyepiece and took another look.
IC 434 and the Horsehead Nebula were suddenly significantly easier to see! The filter significantly darkened the background sky, but not the light from IC 434. As a result, the nebula became easier to see.
I should add that filters such as the UltraBlock do not improve the visibility of all objects in the night sky. Many objects become more difficult to see when such filters are used. Everything depends upon the wavelengths of light and their relative intensities as emitted by the various celestial objects. Furthermore, the effects of many such filters can vary significantly depending upon one's sky conditions and light pollution situation.
For more information on the Horsehead Nebula the curious reader is encouraged to visit Stephen Waldee's excellent Horsehead Nebula Main Page and associated links at:
http://home.earthlink.net/~astro-app/horsehead/index.html
Time: 4:10 U.T.
Telescope: 30cm Newtonian
Magnification: 61x
Filter: UltraBlock
NELM: 6.5
Seeing: Poor
Temperature: +25 F (-4 C)
I started out without using the above mentioned filter. NGC 2024 (also known as the Flame Nebula and Tank Track Nebula) was visible near Zeta Orionis. This nebula has a prominent dark lane running through it.
After shifting the telescope slightly to the south, Zeta Orionis left the field of view. The small, bright nebula NGC 2023 was now easily visible surrounding a star.
The next logical step was to look for IC 434 (a faint 'bright' nebula) and the dark notch within it known as B33 -- the Horsehead Nebula. These objects were visible with difficulty. IC 434 was only slightly brighter than the background sky. The Horsehead Nebula has a reputation for being a particularly difficult object to see visually without the use of a specialized (H-Beta) filter. In order to successfully see this object without a filter one must observe from a dark location that's free from the glow of city lights.
I don't have an H-Beta filter; but I do have an UltraBlock filter. The UltraBlock is a multi-layered, interference filter that selectively blocks the wavelengths of some of the more common man-made light sources (as well as some of the natural sky glow) while allowing other wavelengths to freely pass through. I screwed the UltraBlock filter into the eyepiece and took another look.
IC 434 and the Horsehead Nebula were suddenly significantly easier to see! The filter significantly darkened the background sky, but not the light from IC 434. As a result, the nebula became easier to see.
I should add that filters such as the UltraBlock do not improve the visibility of all objects in the night sky. Many objects become more difficult to see when such filters are used. Everything depends upon the wavelengths of light and their relative intensities as emitted by the various celestial objects. Furthermore, the effects of many such filters can vary significantly depending upon one's sky conditions and light pollution situation.
For more information on the Horsehead Nebula the curious reader is encouraged to visit Stephen Waldee's excellent Horsehead Nebula Main Page and associated links at:
http://home.earthlink.net/~astro-app/horsehead/index.html
14 December 2006
NGC 2174
Object: NGC 2174
Date: 14 December 2006 U.T.
Time: 5:45 - 6:00 U.T.
Binoculars: 25x100 tripod-mounted
Seeing: Good
NELM: 6.0 or better
Temperature: +40 F (+4 C)
Wind: Moderate
The above sketch is a close-up of the binocular view of NGC 2174 (RA 06hr 09.7', Dec. +20 30'). North is up. West is to the right. The sketch covers an area approximately 30 minutes of arc across. This nebula appeared considerably fainter in the binoculars than shown in the sketch. It was difficult to ascertain its edges. A bay-like structure was visible in the southwest. Fainter nebulosity extended southward from the brighter region.
Date: 14 December 2006 U.T.
Time: 5:45 - 6:00 U.T.
Binoculars: 25x100 tripod-mounted
Seeing: Good
NELM: 6.0 or better
Temperature: +40 F (+4 C)
Wind: Moderate
The above sketch is a close-up of the binocular view of NGC 2174 (RA 06hr 09.7', Dec. +20 30'). North is up. West is to the right. The sketch covers an area approximately 30 minutes of arc across. This nebula appeared considerably fainter in the binoculars than shown in the sketch. It was difficult to ascertain its edges. A bay-like structure was visible in the southwest. Fainter nebulosity extended southward from the brighter region.
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