The Messier objects in Auriga (M37, M36, M38)
It's been rainy and windy for most of November and December. Raining hard, too. Buckets. Not exactly the kind of weather favorable to telescope observing.
It's cleared up for the last few days, though. Saturday morning when it became bright and sunny I decided to bag the housewarming party that night (sorry Bonnie) and try to get some observing in. But a raft of clouds formed over the Olympics and by full dark it had become completely overcast. I had been hoping to get a good look at Comet Machholz, but it would have to wait.
The next morning the clouds burned off, and again it was sunny at sunset. I checked the collimation of my scope (a good thing too, as it was seriously out of alignment) and tried to get set up for some eyepiece-projection viewing of sunspots, but I didn't quite get my act together by sunset. (Dang Christmas lights taped to the window.) Still, I booted up my night sky software, SkyMap, and went outside to check what was visible, and to cool off my scope. While I was waiting for my scope to reach the ambient temperature I looked at the Moon, just reaching first quarter; the image was a little shaky, but the Moon's bright enough that it barely mattered. As the image steadied I took a quick look at the Pleiades, always beautiful at low power, and technically my first Messier object of the night (M45). Auriga was just rising in the northeast and I remembered that there were some Messier objects within its borders that I'd never seen. SkyMap confirmed it: three open clusters, M37, M36, and M38, were in a line dropping almost straight down from the midway point between iota Aurigae and theta Aurigae, two stars at the corners of the constellation's squished-hexagon shape. On the map I noticed a small circlet of stars, sort of a "mini-Auriga" that I would use as my marker to find M37, and I went out to try and find them.
I started at iota and, looking through the finderscope, worked my way left (north) and down. I came to a tightish grouping of six stars, so I went to eyepiece and searched for a faint fuzzy a little further north. I didn't find it, and something didn't seem right, so I had to go back inside to consult the map again. (Gotta get me a laptop, to make that easier.) It turned out the group I had found was a slightly brighter grouping with a narrower shape, starting from 16 Aurigae (magnitude 4.5). This group turned out to be a good marker for the actual circlet I was looking for (anchored by phi Aurigae, mag 5.1), and soon I was looking at a few dim, barely-perceptible strings of stars. They seemed to form a sprawling arrow pointing back at phi. Later, I looked up M37 on Hartmut Frommert's seds.org Messier database, and he called the shape a Greek letter pi, but I stand by my arrow interpretation. High power didn't seem to resolve many more stars.
Next, I had to drop straight down (east) past a 6th-magnitude star that was just barely outside of the same field of view as M37, and then past that star about the same distance again to find M36. Here were a number of brighter stars that were arranged in two lines of three in a slightly disjointed V. The brightest members were brighter than anything in M37 but the overall cluster was much more compact; again, high power didn't help much.
Finally, slewing downward again, I had to go past a field-of-view's worth of 7th-magnitude stars, and then nearly twice that distance that showed starless on SkyMap and was nearly so in the actual sky, to find M38. I was worried that's I'd lose my way crossing the featureless void, but it was actually easy to find M38. Its stars are hardly perceptible, but its overall glow gives a sense of breadth. Here, high power resolved more stars and turned the cluster's glow grainy.
I looked toward Comet Machholz, which I knew to be off to the right of Rigel, but it was still too low to hope to see anything. I went inside to waste a few moments while it was rising, and looked up my evening's haul on the Messier database. After about twenty minutes I went back outside; unfortunately it had clouded over once more.
Last night, Monday, it was sunny all afternoon, and instead of working out I left work right at 5:30 so I could get home and get my scope cooling as soon as possible. I got the scope set up and went back to iota Aur right away. Within moments I had found my little pointers in the finder, then the circlet, then M37. Still there, still arrow-shaped. Next I dropped down to M36. Poor little broken V. Then down across the starless dark to M38. Again easier to find than I anticipated, and reminding me of a little starry snow globe.
Having assured myself that I knew my way around these objects, I wanted to try finding M35, down yet a little further and just off the foot of one of the Gemini twins. But it was still too low, so before Cygnus could set in the west I thought I'd try bagging a Messier object that had eluded me last summer. M29 is near Sadr in the center of Cygnus and should be easy to find, but I always tried to find it when it was inconveniently high overhead, and now that it was lower in the west I hoped to have better luck. Sure enough, starting at Sadr and slewing to the left (south) brought me right to 40 Cygni, mag 5.6, the only bright star in the area. Dropping down a little brought me to a tight grouping of six or seven fairly bright stars with very little associated glow. It was so easy to find, I wonder why I couldn't last summer, during my explorations of the Summer Triangle.
Now that I had one of my "ones that got away," I returned to Gemini and M35. It should have been an easy starhop: find 3rd-magnitude eta Geminorum in the eyepiece, then go up (west) about as far as 1 Geminorum only to the north. The trouble was, the dimmer stars in the area that I had intended to use as markers were pretty numerous and ended up confusing more than helping me. I had hoped to use 3 and 5 Gem as landmarks, but I might need to rethink that. However, once I got myself oriented properly the cluster was obvious; M35 was huge! The core consisted of seven brighter stars arranged like a boat or mini-Pleiades. I pointed at the "mini-Alcyone" star near the middle and popped in the high-power eyepiece; stars appeared down to the limiting magnitude and the background appeared very grainy. This must be a huge nearby cluster.
Again, Machholz was still not high enough, especailly considering the closeness of the now-gibbous Moon, so I tried for another target that had eluded me: M1, the Crab Nebula, should be an easy find nearly in the same field as zeta Tauri, but I hadn't been able to find it in previous attempts. Returning to zeta, I noticed an asterism I'd seen before, consisting of a triangle with Zeta at one vertex and three other stars of more-or-less equal magnitude, one at each vertex and one in the center. A short arc of dimmer stars curved down from the northwest vertex star. Based on the stars I could see in SkyMap I thought that I'd see M1 near this arc, but it simply wasn't there.
I couldn't end my Messier-hunting on this note, so I cheated and took in the easy Orion Nebula, M42, which was amazing as usual. Only the central bright areas are visible to me here in the city; the outer wisps fade into the skyglow, although I think I catch hints of them from time to time. Also, I'm pretty sure I can see faint de Mairen's Nebula, M43, across the dark gulf from the Trapezium stars.
Once again, it started to cloud over just as Machholz climbed into the sky, but at least I caught a glimpse of Saturn right before the clouds moved in. The seeing was getting pretty unsteady, but Titan stood out just to the northeast, and I think I caught the Cassini division.
Once inside, I got online to look up M1 on the Digitized Sky Survey to try and find where I went wrong. Well, as it turns out M1 is quite a bit further from zeta Tauri than I thought; the arc of stars could actually have been used as a pointer. Next time, I guess.
Today's catch: M29, M35, M36, M37, M38, M42, M43, M45
The one that got away: M1
It's cleared up for the last few days, though. Saturday morning when it became bright and sunny I decided to bag the housewarming party that night (sorry Bonnie) and try to get some observing in. But a raft of clouds formed over the Olympics and by full dark it had become completely overcast. I had been hoping to get a good look at Comet Machholz, but it would have to wait.
The next morning the clouds burned off, and again it was sunny at sunset. I checked the collimation of my scope (a good thing too, as it was seriously out of alignment) and tried to get set up for some eyepiece-projection viewing of sunspots, but I didn't quite get my act together by sunset. (Dang Christmas lights taped to the window.) Still, I booted up my night sky software, SkyMap, and went outside to check what was visible, and to cool off my scope. While I was waiting for my scope to reach the ambient temperature I looked at the Moon, just reaching first quarter; the image was a little shaky, but the Moon's bright enough that it barely mattered. As the image steadied I took a quick look at the Pleiades, always beautiful at low power, and technically my first Messier object of the night (M45). Auriga was just rising in the northeast and I remembered that there were some Messier objects within its borders that I'd never seen. SkyMap confirmed it: three open clusters, M37, M36, and M38, were in a line dropping almost straight down from the midway point between iota Aurigae and theta Aurigae, two stars at the corners of the constellation's squished-hexagon shape. On the map I noticed a small circlet of stars, sort of a "mini-Auriga" that I would use as my marker to find M37, and I went out to try and find them.
I started at iota and, looking through the finderscope, worked my way left (north) and down. I came to a tightish grouping of six stars, so I went to eyepiece and searched for a faint fuzzy a little further north. I didn't find it, and something didn't seem right, so I had to go back inside to consult the map again. (Gotta get me a laptop, to make that easier.) It turned out the group I had found was a slightly brighter grouping with a narrower shape, starting from 16 Aurigae (magnitude 4.5). This group turned out to be a good marker for the actual circlet I was looking for (anchored by phi Aurigae, mag 5.1), and soon I was looking at a few dim, barely-perceptible strings of stars. They seemed to form a sprawling arrow pointing back at phi. Later, I looked up M37 on Hartmut Frommert's seds.org Messier database, and he called the shape a Greek letter pi, but I stand by my arrow interpretation. High power didn't seem to resolve many more stars.
Next, I had to drop straight down (east) past a 6th-magnitude star that was just barely outside of the same field of view as M37, and then past that star about the same distance again to find M36. Here were a number of brighter stars that were arranged in two lines of three in a slightly disjointed V. The brightest members were brighter than anything in M37 but the overall cluster was much more compact; again, high power didn't help much.
Finally, slewing downward again, I had to go past a field-of-view's worth of 7th-magnitude stars, and then nearly twice that distance that showed starless on SkyMap and was nearly so in the actual sky, to find M38. I was worried that's I'd lose my way crossing the featureless void, but it was actually easy to find M38. Its stars are hardly perceptible, but its overall glow gives a sense of breadth. Here, high power resolved more stars and turned the cluster's glow grainy.
I looked toward Comet Machholz, which I knew to be off to the right of Rigel, but it was still too low to hope to see anything. I went inside to waste a few moments while it was rising, and looked up my evening's haul on the Messier database. After about twenty minutes I went back outside; unfortunately it had clouded over once more.
Last night, Monday, it was sunny all afternoon, and instead of working out I left work right at 5:30 so I could get home and get my scope cooling as soon as possible. I got the scope set up and went back to iota Aur right away. Within moments I had found my little pointers in the finder, then the circlet, then M37. Still there, still arrow-shaped. Next I dropped down to M36. Poor little broken V. Then down across the starless dark to M38. Again easier to find than I anticipated, and reminding me of a little starry snow globe.
Having assured myself that I knew my way around these objects, I wanted to try finding M35, down yet a little further and just off the foot of one of the Gemini twins. But it was still too low, so before Cygnus could set in the west I thought I'd try bagging a Messier object that had eluded me last summer. M29 is near Sadr in the center of Cygnus and should be easy to find, but I always tried to find it when it was inconveniently high overhead, and now that it was lower in the west I hoped to have better luck. Sure enough, starting at Sadr and slewing to the left (south) brought me right to 40 Cygni, mag 5.6, the only bright star in the area. Dropping down a little brought me to a tight grouping of six or seven fairly bright stars with very little associated glow. It was so easy to find, I wonder why I couldn't last summer, during my explorations of the Summer Triangle.
Now that I had one of my "ones that got away," I returned to Gemini and M35. It should have been an easy starhop: find 3rd-magnitude eta Geminorum in the eyepiece, then go up (west) about as far as 1 Geminorum only to the north. The trouble was, the dimmer stars in the area that I had intended to use as markers were pretty numerous and ended up confusing more than helping me. I had hoped to use 3 and 5 Gem as landmarks, but I might need to rethink that. However, once I got myself oriented properly the cluster was obvious; M35 was huge! The core consisted of seven brighter stars arranged like a boat or mini-Pleiades. I pointed at the "mini-Alcyone" star near the middle and popped in the high-power eyepiece; stars appeared down to the limiting magnitude and the background appeared very grainy. This must be a huge nearby cluster.
Again, Machholz was still not high enough, especailly considering the closeness of the now-gibbous Moon, so I tried for another target that had eluded me: M1, the Crab Nebula, should be an easy find nearly in the same field as zeta Tauri, but I hadn't been able to find it in previous attempts. Returning to zeta, I noticed an asterism I'd seen before, consisting of a triangle with Zeta at one vertex and three other stars of more-or-less equal magnitude, one at each vertex and one in the center. A short arc of dimmer stars curved down from the northwest vertex star. Based on the stars I could see in SkyMap I thought that I'd see M1 near this arc, but it simply wasn't there.
I couldn't end my Messier-hunting on this note, so I cheated and took in the easy Orion Nebula, M42, which was amazing as usual. Only the central bright areas are visible to me here in the city; the outer wisps fade into the skyglow, although I think I catch hints of them from time to time. Also, I'm pretty sure I can see faint de Mairen's Nebula, M43, across the dark gulf from the Trapezium stars.
Once again, it started to cloud over just as Machholz climbed into the sky, but at least I caught a glimpse of Saturn right before the clouds moved in. The seeing was getting pretty unsteady, but Titan stood out just to the northeast, and I think I caught the Cassini division.
Once inside, I got online to look up M1 on the Digitized Sky Survey to try and find where I went wrong. Well, as it turns out M1 is quite a bit further from zeta Tauri than I thought; the arc of stars could actually have been used as a pointer. Next time, I guess.
Today's catch: M29, M35, M36, M37, M38, M42, M43, M45
The one that got away: M1
posted by Pete in Space at 5:01 PM
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