Limited Tuesday night observing report, as I’m exhausted from running four hard miles (inspired by possibly running Maryland in a month). All good, no matter what may occur. In any case, tonight was atrocious weather-wise; sticky and humid, with the sky enshrouded in a haze that scattered all the light from Coatesville, the airport, and the house down the street who loves paying PECO for bright yard lights at 11:30 pm. Limiting magnitude at zenith was maybe 4, which was all I needed for this, while near the middle of the sky it was more like 3 (if that). All of it can be attributed to the weather. Anyway, to the observing. First, before dinner, I got Nova Delphini, which AAVSO is pegging between 7.4 and 7.5. I’m somewhat stunned to notice that I wrote about this 48 hours ago, because it seems like many days. Regardless, the AAVSO reports have plateaued, and the nova has not lost anything (or, at least, not an averaged-out tenth) since about September 6 (plus or minus a day; that graph is tough to read). Considering the nova’s past behavior, this is a rather intriguing development, and I’m interested to read professional reports as to why this might be. I can also navigate Sagitta a bit better now. The “jump stars” are easy to find, and Gamma Sagittae (the last naked-eye star in the constellation, at 3.5) has a little two-star “road” in front of it leading to Eta Sagittae (5.05). Finding the nova (which retains its weak orange hue) is easy, and I like to compare it to its companion 8.7 star. You would think the difference between 7.5 and 8.7 is huge, and it is; you’re looking at more than 2.6 times more brightness from the nova than from the star. In practice, though, they’re both rather sedate objects. They’re far below naked-eye visibility, and in my telescope they appear pedestrian. Close study reveals the nova is easily brighter, but it’s not apparent to the level that you’d think. I then moved to Chi Cygni, which I found despite myself. I easily jumped from Eta over the “wall,” but due to Cygnus’ weird orientation (almost on top of the zenith), I couldn’t figure out whether I had caught Chi (the Enclosure has a specific shape, which wasn’t readily apparent). An “Enclosure-like” set of stars (which I learned later was the actual Enclosure tipped on its side due to the perspective), sat near a dim red dot, which was obviously Chi. I had to corroborate that, though, one more telltale bit of evidence that this star is becoming more difficult each week. So, I went out again about 90 minutes later and caught it unequivocally. Perhaps due to the weather (though at 65 degrees altitude at that time, it can be seen as zenith for atmosphere purposes), the star was tough. At 28x it was mostly averted-vision; very little could be done to tease it out directly. At 70x it blinked in and out, then as my eye caught it and focused, it seemed to hold. I do not think its very modest dimming (see below) did that much damage, so I will simply blame the haze again. AAVSO reports are ticking down a bit here, though not much; the last three were 9.8, 9.9, and 9.7. There are only about two observations a day now, and only one on September 10 at all (9.8), so I’m going to go with that, which constitutes a 0.1 magnitude dimming since the last update. Again, though, it may be dimmer than this; the reports are not coming in quickly enough to establish the magnitude in real time like with Nova Delphini. If you told me it was 10 or 10.1, I wouldn’t disbelieve you, though haze can certainly cause an extinction rate of about that much. Perhaps on my next clear night I can see. The only other targets were the ice giants Uranus and Neptune, and both were highly obnoxious targets to find. I started with Neptune, and while I know its exact position, the complete and total invisibility of anything below 20 degrees naked-eye forced me to use Beta and Gamma Capricorni as jump stars (which is like firing a shot over the wall of the fort without looking). I found a tight double in the area east of that star set, in Aquarius, then spent a few minutes just going back and forth through the area. Had this been any of the first ten times I searched for Neptune, this would have been pointless and I would have gone inside. Eventually, though, I came upon the triangle-shape of stars west of Sigma Aquarii from the west (i.e. backwards). I knew I had found Neptune before I confirmed it (I just continued on and caught Sigma, then panned back, so that was cool. Neptune has slid past HIP 110439 and is now out of the triangle, though it retains a very close relationship on the celestial sphere with that star. It will begin to move away now, but that will take some days. When I last observed it, Neptune was parallel to one of the triangle’s lines; now it is just west of the assembly. A reminder that we are talking single-digit percentages of a degree, not visible unless one knows exactly where they’re looking. The view there was just as horrible. Both bodies, Neptune and the star, were a washout, with magnification only making the problem worse. Neptune has never really been magnifiable with my telescope, and this was no different. Going to 70x only smudged the entire image, and I quickly moved on after confirming location. A note that this was the first time I had checked Neptune’s position outside WITHOUT consulting Stellarium until after the fact; I’ve tracked the motion so much in my head that I’d probably recognize the planet at least for the next couple of weeks without needing charts. Finally, Uranus. This was the most obnoxious of all. I initially tried to go off of Eta Piscium (Epsilon was hopelessly invisible). This didn’t work very well; the jump was too far and the dimmer stars too washed out. I kept going, though, hunting in the dark, knowing full well that Uranus was brighter than its companion stars and therefore it would stick out. Plus, it’s got a green tint, so it had the proverbial “sore thumb” going for it. It still took a while, but I eventually stumbled on it by sweeping the area below Pegasus in line with the stars of Aries (both are about 15 degrees away from Uranus and require a lot of tracing). You can’t star-hop that far; I was literally just slowly going up and down, left and right, trying to find the degree-wide assembly of stars that contained Uranus. Eventually I did. This time, I had to crossreference Stellarium, but I was in the right place (the green-white dot of much more substantial brightness made that determination quite easy). Magnification again made Uranus a distinct disk, though very small, as usual. Uranus has passed HIP 3357, by the way, and is now among (rather than next to) an assembly of about seven or eight stars between 7th and 9th magnitude (with a couple outliers). Uranus, at 5.7, is easily the brightest, and can easily be recognized. I mentioned before that Uranus was becoming one of my favorites, and that stands. It’s big enough to magnify, it has an uncommon and rather cool color, and it’s just enough of a challenge to be fun. Finally, one more note. While looking for Nova Delphini, I caught a faint satellite sweeping through the body of Sagitta, entirely telescopically. It was too faint to be seen by the naked eye, but I tracked it through the Arrow then into Aquila before losing it and going back to the nova. Neither Stellarium nor Heavens-Above has any information on it (the satellite was likely too faint), so it will forever remain unknown. Goodnight, all.
Posted on: Wed, 11 Sep 2013 04:10:38 +0000
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