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I recently purchased a TMB 130mm f/9.25 LW version apochromatic refractor. Here is a summary of my first observing reports with the telescope.
As with the other two apochromatic refractors that I purchased from TMB Optical, a 175mm f/8 and 105mm f/6.2 in 2004, the 130mm arrived well packed. I decided to go with the LW version as I don't do much astrophotography these days, and felt it would be lighter to carry and easier for the mount to handle.
I was eager to try the new 130mm out so planned on getting up early the following morning. The forecast was not the best, very cold and windy, but the weather has not been very good for observing since mid-November as it has often been cloudy and snowy or rainy. More often than not when it has been clear the Moon has been up so my opportunity to observe deep-sky objects has been limited. Having snow on the ground that reflects the moonlight or man-made light pollution does not help matters. Also the seeing for the planets has generally not been very good. As observing has been on a catch as catch can type of thing, I decided to set up anyway.
I set the 130mm up the next morning and began observing several hours before the onset of astronomical twilight. It was cold and clear with the limiting magnitude around 5.2. The air temperature was 15 degrees and wind chills in the upper single digits with a persistent westerly breeze. Metal surfaces became so cold that if I touched them without my gloves on my hands would hurt. As expected the seeing wasn't very good, and even though I usually try to let a telescope equilibrate to outside air temperature I did not have the chance to do it this time so I knew it would take a while before observing at higher powers would be possible. So I started off observing deep-sky objects first.
First up was M 35, an open cluster in Gemini, is located 2.5º northwest of eta Geminorum. It has a magnitude of 5.1, and a size of 28.0'. In the 130mm with an AP Maxbright star diagonal 41mm TV Panoptic (29x), 31mm TV Nagler (39x), and 20mm TV Nagler (60x) it was a very pretty cluster with curving rows of bright stars, with an orange and some yellow stars mixed in. The well-known English astronomer William Lassell observed this cluster with his 24" reflector and stated:
"A marvelously striking object - the field of view is perfectly full of brilliant stars, unusually equal in magnitude and distribution over the whole area. Nothing but a sight of the object itself can convey an adequate idea of its exquisite beauty. No one can see it for the first time without exclamation."
On the edge to the southwest of M35 is NGC 2158, an open cluster with a magnitude of 8.6 and a size 5.0'. Although it appears smaller and dimmer than M35 they are actually about the same size, however NGC 2158 is six times further away. It appeared mottled in the 130mm at 60x. William Herschel discovered this cluster on November 17th 1784 using his 18.7" reflector. He placed the cluster in his sixth class, Very Compressed and Rich Clusters of Stars, and as it was his 17th entry into this class, it is listed as H VI 17. Of the cluster he wrote:
"A very rich cluster of very compressed and extremely small stars 4 or 5' diameter. A miniature of (M)35."
Even though I knew the seeing wasn't very good, and the telescope wasn't fully settled down yet, I didn't want Saturn to get too low in the western sky so I observed it next. Regardless, it looked very pretty. I used the Baader binocular viewer with the 1.7x corrector in place and a pair of TMB 16mm Super Monocentrics (128x) and TMB 14mm Super Monocentrics (146x). Four moons were visible nearby, with Rhea and Tethys forming a close pair near Saturn while Titan and Iapetus formed another close pair further away from the globe. Features visible on Saturn included the Equatorial Zone (EZ), a light yellow color, the South Equatorial Belt (SEB), a light brown color, the South Polar Region (SPR) a green color, and the North Polar region (NPR), a blue color.
I had used a Baader Planetarium Moon & Skyglow (Neodymium) Filter often while observing Mars during the recent opposition and found it useful for enhancing atmospheric and surface detail. It works by filtering out skyglow and boosting color contrast by isolating the Red, Green, and Blue regions of the spectrum. I decided to try it for Saturn to see if it would help bring out additional detail under the prevailing seeing conditions. Indeed, it did help to enhance the detail including the Crepe Ring in front of the globe, as well as enhance the EZ, the SEB, SPR, and the NPR.
I found the filter helped to enhancing detail on Jupiter as well, including the belts and zones, as well as festoons and the Great Red Spot. By coincidence, two of Jupiter's moon's, Io and Europa, formed a close pairing on one side of the globe, with Ganymede and Callisto further apart on the other side of the globe.
Some of the spring and summer constellations were rising in the east so I decided to observe some deep-sky objects, including M 13 and M 57. I was surprised how well M13 was resolved in the telescope. For example in the Maxbright using the 41mm TV Panoptic (29x) some of the outer stars were resolved, while the inner core was prominent. In the 31mm TV Nagler (39x) the outer stars were better resolved and the inner core was brighter, while in the TMB 14mm Super Monocentric (146x) the stars were well resolved in outer areas as well as across the core itself. Even though M57 was only 20 degrees in elevation the ring and darker inner portion was well resolved in 24mm TV Panoptic (50x) and TMB 14mm Super Monocentric (146x).
My impression of the telescope after my first observing session was that it performed quite well given the observing conditions, and that the contrast seemed unusually high it in. This was particularly true of M13 and M57, where the detail in these objects just seemed to pop out from the sky background.
The long-range weather forecast did not look good, so I decided to set the 130mm up again the following evening. High clouds were moving in but I was able to get some observing in of the first quarter Moon and Mars. The telescope had more time to settle down this time, and the seeing was better.
Even with the high clouds the detail on the Moon was very impressive. For example the detail along the Caucasus Mountains was remarkable, showing a texture and fine detail that reminded me of rock debris that had flowed downhill. Visible also were Mons Piton, Montes Spitzbergen, Archimedes, Autolycus, and Aristilus. The terminator was just to the west of the Straight Wall. The detail in the crater Deslandres just to the south of the Straight Wall looked very much like the detail in Rukl's fold out lunar map.
I decided to see how high I could push the magnification on the 130mm. The seeing and clouds limited the amount of lunar detail visible by the time I got up to 409x using the Baader binoviewer, 1.7x corrector, and 5mm Super Monocentrics. Just for kicks I took the magnification up to 511x (Baader binoviewer, 1.7x corrector, and 4mm Super Monocentrics) and while the image wasn't good I can see how on nights of steadier seeing this telescope could support over 100x per inch of aperture. Very impressive.
Mars, a diameter of 11", showed very fine detail as well. This included the North Polar Hood, Sinus Sabaes, Syrtis Major, and Mare Tyrrhenum. The seeing was good enough that I could use 341x with the Baader binoviewer 1.7x corrector and a pair of 6mm Super Monocentrics.
I have gotten up early a couple of times recently to observe Saturn and Jupiter with the 130mm. Unfortunately the seeing was only fair at best. Still both planets have shown interesting detail. For example on Saturn the Crepe Ring was visible on both sides of the globe as well as in front of the globe. The Equatorial Zone was a light yellow color, the Equatorial Band was visible, South Equatorial Belt was light brown, and South Polar Region green and the North Polar Region blue in color. The Cassini Division was prominent and the A-Ring was darker than the B-Ring. When the seeing settled down Titan has had a red color to it. Even though the seeing hasn't been the best the telescope has provided some of the prettiest views of Saturn I have ever had.
Jupiter is lower in the sky but it too has shown interesting detail. This includes the North Equatorial Belts and South Equatorial Belts which were both brown in color, hints of other belts and zones as well as festoons in the Equatorial Zone.
I have done some addition deep-sky observing with the 130mm in recent weeks also. One was Izar, a very pretty double star Izar in the constellation of Bootes. Using the Baader binoviewer with 1.7x corrector and a pair of TMB 16mm Super Monocentrics (127x) the double star was nicely resolved, a very pretty yellowish primary star and light blue smaller secondary star.
On another night I observed M 42. Although it was clear there were gusty winds of between 20 to 30 MPH so I needed to set up out of the wind as much as possible. Using a 41mm TV Panoptic (29x), 31mm TV Nagler (39x). 24mm TV Panoptic (50x) and TMB 16mm Super Monocentric (75x) the 130mm showed mottling in the inner portion of the nebula which appeared blue-green in color and a feathered appearance to the outer portions of the nebula. The "bat wings" were visible along the bottom of the nebula, as was M43. While I could resolve the four stars in the Trapezium the seeing was not good enough to resolve the 5th and 6th stars.
Observing conditions were better when I observed M 97. Also known as the Owl Nebula, M97 is a planetary nebula located in Ursa Major. It has a magnitude of 9.9 and a diameter of 170". Pierre Mechain discovered it in 1781. It received its name from a sketch made by Lord Rosse who observed the nebula through his 72" telescope and saw two dark holes that look like eyes peering from a round face. Through the 130mm at 29x (41mm TV Panoptic) and 39x (31mm TV Nagler) M97 appeared surprisingly bright and there were times I felt I could make out to two round darker area of the nebula. At higher magnifications of 50x (24mm TV Panoptic) and 75x (TMB 16mm Super Monocentric) the nebula appeared larger and brighter, and the two round darker areas were seen more often, as well as the 14th magnitude central star which popped into view from time to time.
Overall I have been very impressed with the quality of the telescope and the views it has provided. I had thought that it might do well for the Moon and planets, but based on it's performance on the deep-sky objects I have observed so far I think it will turn out to be an excellent performer here as well.
We had some clear skies recently so I decided to get some more deep-sky observing in with the TMB 130mm f/9.25 refractor while the Moon was near its new phase. The weather conditions were not the best, as the limiting magnitude was around 4.9, and on the best nights at my observing site it is around 5.5. Plus the wind was gusty from time to time, and high clouds drifted through, but as time went on the winds subsided and the skies cleared. I observed for about six hours.
First up was VX Andromedae, a carbon star located not far from the Andromeda Galaxy. Its magnitude varies from 8.0 to 9.5 magnitude in 367 days. Through the telescope at 39x (31mm TV Nagler) and 60x (20mm Nagler) the star had a pronounced deep orange color to it. Carbon stars have surface temperatures that range from 2000K to 3000K and are usually giant variable stars. They have outer shells or clouds of carbon dust that gives them a deep red or deep orange color. It was neat to observe.
I then observed NGC 7789, an open cluster located in Cassiopeia. It has a magnitude of 6.7, and a size of 25'. It has several hundred 11th magnitudes and fainter stars. The cluster was discovered by Caroline Herschel in 1783 using a telescope that her brother William made for her that she could use to sweep for comets, double stars, and nebula while he was away. William observed it on November 3, 1787 using his 18.7" reflector and wrote:
"A beautiful cluster of very compressed small stars very rich."
Through the 130mm the cluster appeared faint and quite large at 29x (41mm Panoptic). It became easier to resolve the stars as I increased magnification to 60x (20mm Nagler). Some of the stars along the bottom cluster appeared brighter than those near the top or in the interior portion of the cluster.
M1, the Crab Nebula, was near the meridian at this point so I swung the telescope over to observe it. At 39x (31mm Nagler) the nebula appeared somewhat elongated and had a light greenish color to it. It appeared mottled at 60x (20mm Nagler).
At low power, 29x (41mm Panoptic) and 39x (31mm Nagler), the central region of the Orion Nebula M 42, was light blue in color and appeared mottled. At higher magnifications (75x, TMB 16mm Super Monocentric, and 86x, TMB 14mm Super Monocentric) there appeared to be some dark striations visible in the central region of the nebula, and the fifth and sixth stars were visible in the Trapezium. Along the bottom of the nebula, the "bat wings" were prominent (visible in this image I took of M42 ), with the left hand side having a slight mauve or light purple color to it, while the right hand side appeared bisected. Extending up from the bat wings the left-hand side appeared feathered as it extended towards the top of the nebula, while the right hand side was more diffuse. M43 was visible below M42.
I had observed M 97 during my last observing session with the 130mm so decided to observe it again as well as M 108, which is located nearby. Both of these objects fit into the same field of view of the 41mm Panoptic and 31mm TV Nagler, with M97 appearing larger and brighter than M108. M108 is a galaxy with a magnitude of 10.6 and is 8.6'x2.4' in size. As with M97, it was discovered by Pierre Mechain in 1781 - 1782. While observing the galaxy at 50x (24mm TV Panoptic) a telescopic meteor appeared and disappeared within the field of view, which was cool to see. The galaxy appears as an elongated slash of light and at 75x (TMB 16mm Super Monocentric) it appears to have some mottling and brighter portions visible near the center. There is also a relatively bright foreground star visible in front of the center of the M108.
At low powers Saturn was very pretty near M 44, which had a mix of yellow and white colored stars. At higher magnifications, using the Baader binoviewer with 1.7x corrector and a pair of TMB 8mm and 7mm Super Monocentrics (255x and 292x respectively), Saturn showed interesting detail. This included the North Polar Region which appeared blue in color, the Equatorial Band visible in the Equatorial Zone which was a light yellow color, the South Tropical Zone which was tan in color, and the South South Temperate Belt which was green in color. The Crepe Ring was visible on both sides of the globe as well as in front of the globe. It has been noted recently that when Saturn is at opposition and its rings are wide open there can be a marked increase in ring brightness. This seemed to be the case when I observed Saturn as the B-Ring in particular seemed brighter. In addition Saturn's moon Rhea appeared larger or brighter than Dione. While it is true that Rhea is larger than Dione, and brighter (Rhea has a magnitude of 9.5 while Dione has a magnitude of 10.2) this was the first time I have noted that Rhea appeared larger and brighter. I will need to observe these moons again in the coming weeks and months and see if there still appears to be a difference in size between them. As I have seen before Titan had a red color to it.
I got up a little after 4:00 am to observe Comet Pojmanski (C/2006 A1) that is currently visible rising in the eastern sky before dawn. I used a pair of Oberwerk 11x70mm and Oberwerk 22x100mm binoculars mounted on a tripod. The air temperature was 8 degrees Fahrenheit but there was little wind so it didn't feel too cold.
Although it was mostly clear with a limiting magnitude of around 5.2 there were some clouds in the eastern sky and some trees to the east of my observing site. So I had to wait for a little while for the comet to rise higher in the sky. By the time the comet had climbed high enough to be seen astronomical twilight had just set in.
Even so the comet appeared relatively bright and strongly condensed with a light blue color to it through both the 11x70mm and 22x100mm binoculars. The pseudonucleus and the coma were visible, and through the 22x100mm binoculars there appeared to be a faint dust tail that extended approximately 1° in length.
It has been reported that the comet is around 5th magnitude, and based on some comparisons with nearby stars with magnitudes between 6th and 4th magnitude this seemed to be the case.
Grzegorz Pojmanski of the Warsaw University Astronomical Observatory discovered the comet on January 2nd when he was examining a photograph taken by the All Sky Automated Survey (ASAS). At the time the comet was roughly 11 to 12 magnitude and visible only from the Southern Hemisphere. However since then it has been moving northward and will make its closest approach to Earth on March 5 when it be 71.7 million miles away.
After March 5th the comet gradually become fainter, and there will be interference from moonlight from March 11th to the 29th.
I observed Jupiter using a TMB 130mm f/9.25 refractor on an alt-az mount. The seeing conditions varied from poor to fair, so I was limited to using a magnification of mostly 170x in the Baader binocular viewer.
In the southern portion of the globe the South Polar Region (SPR) the South Tropical Zone (STropZ), and the South Equatorial Belt (SEB) were visible. The SPR had a tan color to it. The SEB appeared to be bisected by a rift possibly composed of a number of ovals but I wasn't 100% sure, and the southern portion of the SEB was reddish-tan in color. Along the southern edge of the SEB the Great Red Spot (GRS) appeared light pink in color. "Red Spot Jr.", oval BA, was visible along the northern edge of the SPR but I did not note a red color to it.
There were several prominent festoons visible along the North Equatorial Belt (NEB) south. The NEB had a reddish-brownish color to it. The North Tropical Zone (NTropZ) was visible between the NEB and the North Polar Region (NPR). The NPR had a green-tan color to it.
When the seeing settled down the Jovian moons appeared as disks and had subtle but noticeable differences in size and color.