68º-58º F clear, calm, humid!
No moon (26 days)
Transparency very good
Celestron 8” Nexstar Evolution
Eyepieces: 40mm, 32mm, 13mm, 9mm, 8.8mm, 6mm
First real observing session with the new C8. It performed very well. I started by playing with the collimation (mirror alignment) a little, but it was really pretty good, even at 500x. Nice job, Celestron!
Then it was off to the races. Having GOTO and tracking is AWESOME! I was out to do more survey work than studying anything in detail, just seeing how the scope performed on different objects. So I looked at planets, globular clusters, nebulae, open clusters, and galaxies. The seeing (measure of atmospheric disturbance) made the planets a little challenging, but I was pleased nevertheless.
Jupiter was super bright, but it was hard to get much detail due to the poor seeing. The two equatorial bands were obvious, kind of thin; a few blue-gray spots under the (… oh dear, which way does an SCT turn things?… ah! Here we are. With a diagonal, it’s right side up, but mirrored left to right.) NEB; a few fainter bands visible; blah blah blah. What was especially interesting was that little black dot right about the meridian and half way up the northern hemisphere. It was visible at low power (62x), but I wasn’t convinced at first it wasn’t an artifact. At higher magnification (222x was best), it remained, so yes, a moon shadow I think! One of the moons appeared just west of the planet, so was it that one? I thought there might be a hint of something emerging from the disk in the NW, but didn’t give it much time or thought. Going back to low power, there were only three moons visible, so something was transiting or eclipsed. Upon research after the fact, it was Io that was transiting and was emerging at about 22:38, which is about when I was there. The shadow was also of Io, which exited the disk at about 23:45. This is consistent with what I saw. I returned to Jupiter later, sometime after midnight, and at 222x there were two moons hanging out west of the disk. So the one I had seen which was westerly of Io was Europa. Ganymede was to the east, and Callisto was way west.
Saturn was better behaved, being not so obnoxiously bright as Jupiter, but still wobbly. Always just such a remarkable sight, though. Even at low power I could see the Cassini Division popping in and out. The rings are still wide open, but now are encroaching on the planet disk. It is still close to opposition, so there isn’t much in the way of disk shadow on the rings, and with the seeing as poor as it was, not much ring shadow on the disk, either. The northern hemisphere change in color was visible, going from yellow near the equator to greenish over the pole. The rings outside Cassini Div. were noticeably darker than those inside. That’s about it for detail that I remember. I did push up to 333x without much benefit or cost.
Went on a tour of globular clusters after that: M4, M3, M5, M10, M12, M80. I was surprised at M4 (in Scorpius) that it was as dim as it was. I remember struggling with it with the 8” Newtonian because it seemed low contrast against the background. I guess it’s just so! There was no bright core to it, just a grainy patch surrounded by a broad ring of resolvable stars. There is a band of stars that stands out running N to S over the center. This is the defining characteristic I remember from previous views. M3 (in Canes Venatici) isn’t where I thought it was, which is over near Ophiuchus, but more on that later. It is a big, bright globular; bright center covered with grainy, resolvable stars at 154x. This is where all these globs start sounding the same, but it is really an impressive object. M5, which is closer to what I thought was M3, but still not where I thought that was either (it’s actually in Serpens Caput), is another really lovely glob. Tight bright core surrounded with a mantle of bright stars. Should have written about it on the scene, as now it’s escaping me, but I just kept saying, “Wow, that’s gorgeous!” M10 is also very pretty in much the same way, just a little less so. M12 is tiny by comparison to all these others, but also very pretty. (10 and 12 are in Ophiuchus.) The other night I was looking around with binocs and saw a big, lovely glob in Ophiuchus, which I thought was either M3 or 5, but now I know it wasn’t either, so I think it must have been M10, except that isn’t where I thought I was looking. The closest to where I thought I was looking is actually M107, but that is really small, so it probably wasn’t. Oh, well. Let’s move on.
By now the Milky Way was well up, and Sagittarius had cleared the trees, with the Teapot sitting nice and level. So I made a run up the galactic core nebulae. Starting with M8, I was astonished that it filled the field of view at 154x (13mm). The nebulosity was visible but not super obvious. I backed off to 62x and maybe that’s when I broke out the 40mm for 50x, even. M8 is just huge! Two bright stars stacked N-S just W of center, then a cascade of smaller stars to the east. Nebulosity most noticeable around the two bright ones with a dust lane cutting between them and the cascade. A small brighter patch of neb just W of the southern of the two stars. Does that make sense? Might need darker skies or a filter to enhance the contrast and bring out the nebula some more.
M20, the Triffid, is tiny and faint by comparison. Also centering on two N-S stars, but much smaller and closer together. (I should learn how to talk about these in terms of magnitude some day.) If averted my gaze, I could sort of see the nebula and the dust lane that divides its lobes. I don’t think it was just constructed from memory. Again, more contrast would help here.
M21 is a small open cluster. Next to these other show pieces, it’s no wonder no-one pays attention to it. Including me. Next….
M24 is the galactic star cloud, which would be a good name for a 70s pop band. It is so big that even with the 40mm, it just looks like a lot of stars. Which of course is what it is, but it isn’t identifiable here as an “object.” Really need binoculars for this one. Just saw something about it, though, pointing out it is actually a hole in the galactic dust lane that allows us to see these stars that are near the heart of the galaxy. It’s not really a cluster of any sort. So that’s cool.
M17, the Swan Nebula, is always a favorite of mine. Here it appears to be on its head. The loop of its neck, as it were, concave to the west with two stars on the curve. The body runs from west to east, pretty large and obvious. (I should learn how to talk about these things in terms of arc minutes and arc seconds some day.) Will always remember how it appeared in the 25” scope in New Mexico. Ohh baby.
M16, the Eagle Nebula, appears as a small open cluster without much in the way of nebula. Again, with some averted vision I could pretend there was some nebula, but I wouldn’t swear to it.
Mars had now made its way up to a reasonable height, for all the good it did me. Poor seeing, still a relatively low altitude, and the planet-wide dust storm it is undergoing all conspire to make the current appearance of Mars, just 3 weeks from the closest approach in 15 years, a mess to look at. Basically no detail at all, just a salmon-colored ball. Not so much as a polar cap. I think I went up to 222x. At some points with a little averted vision, I thought I could make out some faint surface markings, but I wouldn’t swear to it. I tried a couple filters. What I think turned out to be a green filter had the interesting effect of making the disk essentially white. Wasn’t expecting that! Again, some impression of faint surface markings. Tried a red filter, which was really, really RED and made everything RED! Not very helpful, but interesting. Tried it on Saturn, too, with much the same effect. Upon further research, it appears that Syrtis Major should have been about on the meridian at midnight, so it is possible I was seeing some of its outline.
By this time things were getting damp. I mean, there was water standing on things on the table. I had my dew shield on the scope, but when I checked, there was some dew on the corrector. I pressed on a little more to catch a few galaxies.
M51, just south of the tip of the Big Dipper’s handle, is always a favorite. It appeared as two bright blobs, the cores of the two galaxies, surrounded to the SW especially by nebulous fuzz. No real sense of structure at all. I think I was running at 154x? Or maybe it was the 32mm at 63x.
Popped over to M81, Bode’s galaxy, a large elliptical that looked kind of an oblong blob. I think I was using either the 32mm or the 40mm and expected to find M82 right next door. I didn’t. So I didn’t spend much time with 81 and went to 82, but again its neighbor was not in sight anywhere. I thought they should both appear in the same field of view at low power, as they are less than a degree apart, but couldn’t find both at the same time after some searching. M82 appeared as a long, bright slash running SW to NE.
By now I had serious dew on the scope. I also had not set the scope up high enough that I could just stand, so I was doing a lot of half bends or high squats, and I was getting tired. All in all, the scope performed admirably. The goto worked really well, and the tracking was quite steady, and these were the things I really wanted in a computerized mount. The tracking motor buzzes in cycles, which may have been enough to send a vibration through the image, which I noticed especially on Saturn. It’s possible, though, that it was just the rippling of the atmosphere keeping time with the mount. I hope for a bit better experience on planets with better seeing conditions. Deep sky will also need some getting used to, trying to find the right magnifications for the various types of objects. The globs and open clusters were the winners of the night. After taking the scope off line, I just spent some time looking, as it was still a really beautiful night, and it felt good to sit down for a few minutes. As usual, I thank God for the beauty of the night sky, the eyes, time, and equipment to behold it, and for all peace I feel in the process.
Stuff I looked at:
Jupiter – with moon shadow
Saturn – Cassini division w/ 32mm
Mars – totally washed out with dust, but maybe a few surface features
M3 – very nice
M4 – oddly dim
M5 – absolutely gorgeous
M8 – enormous
M10 – beautiful
M12 – adorable
M16 – hint of neb
M17 – lovely
M20 – pretend it’s there
M21 – meh
M24 – better in binocs
M51 – getting dewed, dude; two cores and some fuzz
M80 – very pretty
M81 – visible blob
M82 – long, thin, bright
5 thoughts on “Observing, 8 July 2018”
It’s great that you were able to see a moon’s shadow on Jupiter! Bummer about the dust storm on Mars. One question – what does “seeing bubbly” mean?
The “seeing” is a measure of how steady the atmosphere is. It was not steady that night! I guess I need some punctuation in there – “seeing: bubbly”
LikeLiked by 1 person
Hi, thanks for the observing report. I was hoping Mars would at least have a good size area of polar clouds to give some contrast in small scopes. 😦 I haven’t looked yet, so I don’t know for myself.
Yes, Mars is currently a total wash-out. Very disappointing. Fortunately, our atmosphere doesn’t get that bad all at once!
Comments are closed.