#1
|
|||
|
|||
Demos and Phobos
After the visitors and most members had left our Mars openhouse at clubs
observatory two of us spent the early morning hours looking for the two moons rather than surface detail. The nearby 9.95 magnitude star (TYC6386-00334-1), Sky and Telescope's Mars moon java applet and TMB SuperMono's were critical to the hunt. All observations were made sitting down, one must be comfortable and patient to wait for the moment of good seeing. The sky conditions were mostly clear with some thin clouds, no wind and high humidity. After 5UT the seeing improved to being variable from a 7 to nearly a 9. I had my AP130F6 and he a 13" Dob with a good galaxy mirror. After trying for a half hour to 45 minutes looking unsuccessfully for Demos I switched to the 13" Dob. I put in my 4mm TMB SuperMono and was able to find Demos after about 15minutes of looking at 6:10 UT. Had to keep Mars outside of the FOV though. It was not visible in the other observers 4.8 Nagler due to excessive light scattering. The dob had not been set up on it's platform but smooth hand tracking keeping Mars on the edge of the field stop was possible or 30 to 40 seconds before more rapid motion was needed to reposition the planet. The nearby star made for a convenient estimator for the magnitude and position of Demos. With the visual field now know I went looking for it again with the AP130 and after another half hour of looking was able to get it using either a 4 or 5mm TMB SuperMono straight through (no barlow or diagonal). Demos was frequently not visible for periods of time as the transparency of sky conditions varied. However, when visible it was visible 100% of the time. The sighting in the AP130 was confirmed by the other observer and we bounced back and forth between the two scopes with our observations after that. The first observation was about 1 hour before greatest elongation (7:12UT per S&T). A driven scope sure makes it easier to keep Mars just outside and adjusted it north or south on the field stop. I was not able to get Demos with my binoviewer and TMB 8 or 10mm eyepieces with or without a barlow. After Demos we started looking for Phobos as it started to approach greatest elongation. I had one clear view at 6:50 UT for approximately 1 minute of the star, Demos and Phobos in their expected positions using the AP130 and TMB 5mm. This was approximate 1hr before maximum elongation (7:53 per S&T). The sighting was not confirmed by the second observer nor repeated by myself over the next hour, although Demos was frequently visible. I packed up at 4am since sky transparency had fallen off and Demos became less frequently visible. So did we see the moons in a 5.1" scope? Demos for sure, many times, and it's motion relative to Mars and Mar's motion relative to the star were obvious. I believe I saw Phobos as it was clear and steady for a short period of time. |
#2
|
|||
|
|||
Demos and Phobos
In article
, "Enyo" wrote: After the visitors and most members had left our Mars openhouse at clubs observatory two of us spent the early morning hours looking for the two moons rather than surface detail. The nearby 9.95 magnitude star (TYC6386-00334-1), Sky and Telescope's Mars moon java applet and TMB SuperMono's were critical to the hunt. All observations were made sitting down, one must be comfortable and patient to wait for the moment of good seeing. The sky conditions were mostly clear with some thin clouds, no wind and high humidity. After 5UT the seeing improved to being variable from a 7 to nearly a 9. I had my AP130F6 and he a 13" Dob with a good galaxy mirror. SNIP_ So did we see the moons in a 5.1" scope? Demos for sure, many times, and it's motion relative to Mars and Mar's motion relative to the star were obvious. I believe I saw Phobos as it was clear and steady for a short period of time. An excellent post- thank you. I saw Deimos three times this past week, and Phobos once with a 6" f/9.4 AstroPhysics Starfire with Tak LE 5mm and 4mm Zeiss Abbe Ortho. After identifying them, I could drop the magnification somewhat. I agree with your comments about making yourself comfortably seated and spending a good long time looking. Having a good planetarium program is also a big help (I use Starry Night Pro). And some of the faint field stars that have been so common lately are useful for both position and magnitude. Since my scope is set up permanently, it is very accurately polar aligned, which is a BIG help in keeping Mars in the precisely needed position just out of the field of view. When I saw them, I was pretty sure they could be seen in something a little smaller. You have confirmed my suspicions. During the last edgewise presentation of Saturn's rings, I was able to find Enceladus and Mimas with the same 6"scope. I thought that was remarkable, but finding Deimos and Phobos was tougher. Starry Skies, Rich PS: On the one night that I found them both, I tried to see them at the same time. Couldn't do it. If I left one to look at the other, the first one would disappear....... |
#3
|
|||
|
|||
Demos and Phobos
In article
, "Enyo" wrote: After the visitors and most members had left our Mars openhouse at clubs observatory two of us spent the early morning hours looking for the two moons rather than surface detail. The nearby 9.95 magnitude star (TYC6386-00334-1), Sky and Telescope's Mars moon java applet and TMB SuperMono's were critical to the hunt. All observations were made sitting down, one must be comfortable and patient to wait for the moment of good seeing. The sky conditions were mostly clear with some thin clouds, no wind and high humidity. After 5UT the seeing improved to being variable from a 7 to nearly a 9. I had my AP130F6 and he a 13" Dob with a good galaxy mirror. SNIP_ So did we see the moons in a 5.1" scope? Demos for sure, many times, and it's motion relative to Mars and Mar's motion relative to the star were obvious. I believe I saw Phobos as it was clear and steady for a short period of time. An excellent post- thank you. I saw Deimos three times this past week, and Phobos once with a 6" f/9.4 AstroPhysics Starfire with Tak LE 5mm and 4mm Zeiss Abbe Ortho. After identifying them, I could drop the magnification somewhat. I agree with your comments about making yourself comfortably seated and spending a good long time looking. Having a good planetarium program is also a big help (I use Starry Night Pro). And some of the faint field stars that have been so common lately are useful for both position and magnitude. Since my scope is set up permanently, it is very accurately polar aligned, which is a BIG help in keeping Mars in the precisely needed position just out of the field of view. When I saw them, I was pretty sure they could be seen in something a little smaller. You have confirmed my suspicions. During the last edgewise presentation of Saturn's rings, I was able to find Enceladus and Mimas with the same 6"scope. I thought that was remarkable, but finding Deimos and Phobos was tougher. Starry Skies, Rich PS: On the one night that I found them both, I tried to see them at the same time. Couldn't do it. If I left one to look at the other, the first one would disappear....... |
Thread Tools | |
Display Modes | |
|
|