Once again, the Boston Globe’s Big Picture feature is doing a Hubble advent calendar. Every day between now and Christmas, you’ll get another brain-exploding picture of some unspeakably huge and distant space thing. Point your browsers here.
Archive for the ‘Planetary nebula’ Category
There is a certain segment of the population that, when encouriaged to get outside to do a little stargazing, says, “Nah, I’ll stay inside and surf for pictures on the internet.” I don’t advocate doing this instead of going outside and seeing things for yourself, but I’m certainly not opposed to surfing for pictures in addition to stargazing. And this is a good time to do it!
Hubble is back, baby, and the Hubble team showed off the rejuvenated telescope’s mojo with a ream of mind-bendingly awesome pictures, many taken by the newly installed Wide Field Camera 3 (WFC3). These have turned up all over the astro-blogosphere. My favorite is the Butterfly Nebula, NGC 6302, a planetary nebula blown off by a dying star (at top). Would that we could all go out with such grace.
For my money, the coolest non-Hubble camera in existence is the HiRISE camera on the Mars Reconnaissance Orbiter. Image above shows craters and ridges in Hesperia Planum (full version here). The archive of publicly available images from HiRISE continues to grow; go here and spend some time exploring another planet.
We started observing with the Mt Wilson 60-inch at about 8:15 PM Wednesday evening. We aimed at Arcturus first, just to make sure that everything was in good working order. Then we split a nearby double star, Epsilon Bootes. After that we got started in earnest. Our first deep sky object (DSO) was M13, the great globular cluster in Hercules. This vast sphere of several hundred thousand stars was discovered by Edmund Halley in 1714. It has special significance for me because it was the first object I observed through the Great Lick Refractor on September 15, 2007, on the night that my lifelong interest in astronomy finally caught fire. In the 60-inch telescope M13 filled the field of view. It almost exhausted the eye, there was so much to look at.
Then we went outside at about 9:20 to watch an Iridium flare–the sudden brightening of a giant solar panel on one of the Iridium communications satellites. It was the first time I’d seen one, and it was pretty cool.
Then it was back inside for more telescopic goodness. Post-flare we looked at NGC 6543, the Cat’s Eye Nebula. This is another summer to early autumn classic, and another object that I first viewed through the Lick Refractor almost two years ago. It was even better in the 60 inch telescope, a visibly S-shaped swirl of green with hints of structure around the central star.
Then it was on to Jupiter, which was huge. The visible Galilean moons were not just points of light in the eyepiece but little spheres; they looked like the worlds that they are. An odd side effect of looking through the giant telescope was to make us appreciate our own scopes more. For picking out detail on nearby objects like Jupiter, atmospheric turbulence is often more limiting than telescope optics. I’m not going to lie and claim that the views in my 6-inch telescope are as good as the views through the Mt. Wilson 60-inch–but on Jupiter I reckon that the 60-inch scope delivered twice as much detail as my scope, rather than the ten times more detail that optical theory would suggest. If the 60-inch was up on Mauna Kea and not plagued by light pollution, smog, and turbulence, it would perform a lot better–as would any telescope. I’m not complaining. Just observing that although our backyard scopes don’t show nearly as much as big observatory scopes, they still show quite a bit.
There was another way in which the views Wednesday night made me appreciate my own telescopes more. Galileo discovered the moons of Jupiter, and he never saw them through a telescope with a diameter of more than an inch. The finderscope that I use on my airline-portable travel telescope has a bigger aperture and sharper optics. And yet Galileo changed the world with the observations he made through his tiny, optically terrible telescope. To get to see the Galilean moons as little worlds in the 60-inch reinforced how ridiculously fortunate all of us are to have such nice tools available.
Speaking of tools, we got to take turns photographing Jupiter through the eyepiece. As is often the case, I got my best picture in the first few snaps. I was so busy previewing my pictures and talking with the other visitors that I completely missed the next object, planetary nebula NGC 7662, the Blue Snowball. Many thanks to Tom Mason, our scope driver, for sharing the photo below.
Faint DSOs require light-gathering ability primarily and not the resolution of fine details. The 60-inch totally blew away any backyard scope on planetary nebulas. After the Blue Snowball we checked out another, even more famous planetary nebula, the Ring Nebula or M57. In backyard scopes it looks like a perfect little doughnut of gray smoke. In the 60-inch it was a huge and green, with threads of gas and dust visible in the middle. I could even make out the central star, which is a legendarily tough object to detect visually.
After the Ring we went back to Jupiter, and then on to Neptune, which is currently close by Jupiter in the sky, just as it was for Galileo four centuries ago. Neptune is incredibly distant, 4.5 billion kilometers away. That’s 30 times farther from the sun that we are, and 6 times farther away than even Jupiter. Even in the 60-inch Neptune was small, but it was visibly a sphere, which is quite an achievement for any Earth-bound optical telescope. Coming down the ladder, I had to remind myself that Neptune is now the most distant planet in the solar system, since Pluto was (correctly, IMHO) demoted to dwarf-planethood.
The final object I observed through the big gun was the Saturn Nebula, NGC 7009, another planetary. It looked much like its namesake. Click on the link above, get 10 feet back from your computer, and you’ll have a pretty good idea of what I saw through the 60-inch.
By the time I’d gotten down the ladder from looking at the Saturn Nebula, it was 3:00 AM and time for me to skidaddle; I had to teach Thursday morning and that meant getting at least a little sleep. On the way out, though, I did stop long enough to enjoy a view of the newly-risen Pleiades in my binoculars. You can do the same if you’re willing to get up in the middle of the night–or you can look forward to a Pleiades mission here in a few months. It all comes back around.
Lots of things came back around for me Wednesday night. M13 and the Cat’s Eye ushered me into astronomy, and it was great to revisit them with two years of knowledge and experience under my belt–as well as 24 more inches of aperture.
What I wanted most from the evening, though, was to photograph Jupiter and its moons. They were the first things I ever viewed through a telescope, in my high school astronomy class. They were also among the first things that Galileo observed with his telescope, 400 years ago this December. I wish he could see how far we’ve come–and how much we owe him.
Finally, a huge thank you to the Pomona Valley Amateur Astronomers for inviting me along and being such gracious and interesting hosts. I had the time of my life. If you ever get the chance, go.