Archive for the ‘Observing philosophy’ Category

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Big fish with light tackle

October 20, 2013

From the first time I read it, I have had a strange fascination with Jay Reynolds Freeman’s “Refractor Red meets the Herschel 400” (available here), wherein he describes observing the legendary deep-sky list with a 55mm refractor. Freeman wrote, “Ask people who land big fish with light tackle, why I do what I do.”

Lately I’ve been working through a slew of the open clusters in the Herschel 400 myself. And I have found that some clusters are dead easy to recognize as distinct bright patches in my 9×50 finder, but at the eyepiece they just sort of dissipate into the background starfield. That plus some fairly transformative rich-field experiences with small refractors (like this one) are working some kind of alchemy on me.

In a feat of Freeman-like proportions, my friend and frequent 10MA contributor Terry Nakazono has logged and sketched over 500 DSOs in the past 3 or so years, including 368 galaxies, almost all with scopes under 5″ aperture, mostly from at least somewhat light-polluted skies. He is just religious about dark adaptation, averted vision, and patience.

Possibly as a result of all of the above, lately I have had this mad desire to go out to the desert with a 70mm or even a 50mm refractor and spend the whole night observing with only that instrument. It feels like my reverse aperture fever and my deep-sky interests are slowly colliding. That plus a sort of perverse desire to knowingly commit to a “suboptimal” (aperture-wise) observing program just because it sounds fun.

I shared this plan on CN and fellow user blb wrote:

No mater what size telescope you use, it seems that you are looking at objects that are on the limits of what can be seen with that size scope. Once I realized this and read, some years ago now, what Jay Reynolds Freeman had to say about his observations, I came to realize there were way more objects to be seen in a small telescope than I would probably see in my lifetime.

I think this is exactly right; I find that with whatever instrument I have to hand, I tend to throw myself up against its limits.

AstroMedia plumber's telescope: a 40mm achromat made with plastic plumbing fittings

AstroMedia plumber’s telescope: a 40mm achromat made with plastic plumbing fittings

In particular, I know that all of the Messier objects have been logged with a 50mm telescope. What about a 40mm scope? I see that AstroMedia has a 40mm f/11 achromat kit (also available from AstroMediaShop.co.uk). That is strangely fascinating to me. (It would be simpler to use a larger scope and simply stop it down to 40mm, but somehow it seems more “pure” to use a scope with a native aperture of 40mm.) However, I think I would first do a Messier tour with a Galileoscope; just because other people have found all the Messiers with a 50mm scope doesn’t mean that I will, and it makes sense to start with that easier goal before plunging right into uncharted territory. It would be mighty tempting to put the 40mm scope and the Galileoscope on the same mount, though…

So…I’ll keep you posted.

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The Rule of Ones

October 19, 2013
C102 2013-10-18

Tonight: one scope, one target. Here’s the scope.

I have several distinct modes as a stargazer. Sometimes I’m in exploration mode and I want to see and log new objects. Sometimes I’m in gear mode and I want to see how a given piece of equipment performs. Sometimes I’m in aesthetic mode and I just want to look at beautiful things. Sometimes I do all three in one night, or even looking at one object.

The last post, about current and future observing projects, was written in exploration mode. “Exploration” might seem like an odd word to apply to the activity of tracking down lists of things compiled by other observers. But if I haven’t seen them myself, then there is still the thrill of the hunt and the rush of discovery. And looking at all of these things is how I personally transmute caelum incognitum into known space. That’s exploration in my book.

Saturday night at the Salton Sea, I was in a blend of aesthetic mode and gear mode, because my ongoing thought process was basically, “Oh, hey, that beautiful thing is up now. I wonder how it looks through these scopes?” I think the only new thing I logged was 8 Lacertae, and if I hadn’t been so close to fiinishing the Double Star program, I wouldn’t have logged any new objects at all, despite staying up almost all night.

I do like observing lists. Some people dismiss them as stamp collecting or say that they make a fun pursuit into work. Well, different strokes, I guess. For me, observing lists come with the implicit subtitle, “Hey, here are the next n-hundred things that are really out there to be seen, any of which might knock your socks off.” Every observing program I have completed has introduced me to new favorite objects, which I periodically revisit, and has broadened my knowledge and experience of the cosmos.

But with all of that said, I don’t do enough casual stargazing, with no plan or agenda. That’s all I used to do, in my first few months as an amateur astronomer, and it almost killed me. Observing programs gave me a way to simultaneously learn the sky and educate myself about what’s up there. But the pendulum may have swung too far now; I hardly ever haul out a scope just to take a quick peek at the moon or Saturn.

All of this is on my mind because of a thread on CN called “When astronomy becomes a chore….” Here’s are some excerpts that have been much on my mind:

RussL: If I feel lazy I can get by with just the 120ST and my trusty TV Widefield 32mm. That way I don’t even have to feel obligated to see each object at every power I can. Easy.

Me: Peace through deliberately limited options–I love it! You have inspired me, sir.

RussL: Well, thanks. I’m glad to know my laziness has helped someone. But, it’s true that sometimes we need to relax more. It’s kinda like when I was a kid with next to nothing to view with, but happy as a clam with whatever I had. I have much more now, although not all that much. I guess part of the difference nowadays is that I have so much more knowledge and feel like I need to use it more. But there’s also a lot to be said for just having a good time without feeling like I must do everything possible.

karstenkoch: I’ve been mentally kicking around an idea for awhile that is still taking shape in my head. For lack of anything better to call it, I’ll call it the “Rule of Ones”. I’ve seen some comments above like it, so I thought I would mention it. There’s really nothing to it other than in order to keep things simple, easy, pure, and enjoyable do or choose only one of everything. Take one scope outside. Take only one eyepiece too. Pick one target to observe. You can imagine all of the other variables involved … choose or do only only one of each. Then, with no more decisions to make, just have a rest under the stars and enjoy your time observing and reflecting.

I like that. One scope, one eyepiece, just go. That sorta dovetails with another idea that has been growing in my mind–more on that in the next post.

Full moon - Oct 18 2013

And here’s the target.

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Letting the crazy out

April 24, 2011

From 2001 to 2006, we lived in Santa Cruz. This was before I became an amateur astronomer. Spring was storm season, which pretty much made it my favorite season. In the morning after a big storm, you could drive over kept strewn across West Cliff Blvd by the waves and wind. I used to go out the cliffs and just sit on the rocks. When a big wave came in and crashed against the cliffs, you could feel it, as if someone had gently kicked your chair. It was mesmerizing, watching the waves, thinking about the fact that the ocean had been there longer than life itself. Staring into that immensity always seemed to put me right with the world. My problems shrunk to manageable size. I often went down to the cliffs frustrated and bent out of shape and left with a little perspective and a little portion of calm.

I called it “letting the crazy seep out”. I don’t remember where I got that phrase, but it is one of my touchstones. It doesn’t just happen at the seaside (which is good, considering that I only lived next to the ocean for 1/7 of my life). Long drives through desolate country also do the trick, especially at night. Hikes of any length. The desert is a marvelous sponge for the accumulated mental grime of civilized life.

So is the night sky. I usually go out to observe with a purpose in mind–some new target to track down, or an old favorite I haven’t seen this season, or just to stare in awe again at the rings of Saturn or Jupiter with its little entourage of moons. But whatever purpose gets me out there looking up, one of the effects of stargazing for me has always been to let the crazy seep out. As if the telescope is a big syringe, drawing the poison out through my pupils. When I first realized this, back in Merced, I started to think of the night sky as another seashore. Carl Sagan’s description of the surface of the earth as “the shore of the cosmic ocean” resonates for me. If sitting on the cliffs in Santa Cruz brought me face-to-face with immensity, stargazing gives me a brush with eternity. I usually leave more tired but less crazy, and that’s a good trade.

Someone said of E.E. Barnard that he was a true observer because if he was prevented from making astronomical observations for any length of time, he got cranky. I can certainly relate. I am in a similar state right now. It’s been cloudy all week. It was cloudy the week before last. It cleared off last weekend, just in time for the camping trip to Owl Canyon, but the nearly-full moon and unsteady seeing made for one of the least satisfying nights of stargazing I’ve ever had, to the point that I gave up and went to bed at midnight (horror!). It’s not supposed to really clear off until Monday.

I did get out tonight, briefly. I was taking out some trash a little after 11:00 and noticed that the sky was mostly clear. By the time I got some warm clothes on, grabbed all my gear, and got set up out in the driveway, that was no longer true. Clouds from the west had already passed the zenith and were creeping down the eastern sky. Saturn and Virgo were already gone, and the Big Dipper was rapidly getting submerged in the soup. I tried without success to find a double star in Bootes, but it was eaten by the clouds too soon. The only stars I could make out lower in the sky were those of Hercules. I cruised down to M13, the Great Glob, mostly so I wouldn’t get completely skunked. It was barely there, but I swapped eyepieces around until I found the best magnification for this evening (75x; it might be higher or lower on other nights, under other conditions), cupped my hands around my face, and stared until the lights went out, which didn’t take long. Less than 10 minutes after I got the scope set up, the sky was completely socked in.

Needless to say, the experience was the opposite of therapeutic.

I know it’s probably galling for some to have a SoCal resident complaining about a measly week or two of clouds. William Herschel discovered 2500 or so deep sky objects, several hundred double stars, and the planet Uranus from England, where clouds are nearly omnipresent, sometimes even coming into people’s houses and carrying off their children. Herschel earned a post as Astronomer Royal, so stargazing was both his obsession and his occupation. If he could put up with a career of observing from England, I’m sure I can suck it up for a couple more days.

I hope so. The crazy is building up.

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So close and yet so far

August 24, 2010

Some of the folks on Cloudy Nights have really cool quotes in their sig files. Last night I came across this one, which crystallizes the elusive feeling that I catch on some nights and pursue on all the rest:

There is a moment after you move your eye away
when you forget where you are
because you’ve been living, it seems,
somewhere else, in the silence of the night sky.

I figured this had to be part of a poem, so I Googled it, and found the original source here. It’s a poem entitled “Telescope” by Louise Gluck, and it originally ran in New Yorker on January 17, 2005. Since it’s already out there on the intarwebz, I don’t feel bad about reproducing it with attribution.

Telescope

by Louise Gluck

There is a moment after you move your eye away
when you forget where you are
because you’ve been living, it seems,
somewhere else, in the silence of the night sky.

You’ve been stopped being here in the world
You’re in a different place
a place where human life has no meaning.

You’re not a creature in a body.
You exist as the stars exist,
participating in their stillness, their immensity.

Then you’re in the world again.
An night, on a cold hill,
taking the telescope apart.

You realize afterward
not that the image is false
but the relation is false.

You see again how far away
each thing is from every other thing.

I think it’s a smashing poem and I wholly agree with the sentiments expressed, right up until the last two stanzas. Then, as far as I’m concerned, it all goes straight to heck.

– – – – – – – – – –

M8 photographed by Rob Gendler

One of the things I like best about observing is that with very modest equipment, one can see most of the stages of the life cycles of stars. Turn to M8, the Lagoon Nebula, or M42, the Great Nebula in Orion, and you can see stellar nurseries. The nebulae are great clouds of gas and dust that are only visible because they are illuminated from within by the terrifying light and heat of newly formed stars.

This process cannot last forever. Even as the last few protostars of a nebula straggle into ignition, their older siblings are blowing away the nebular cocoon by the force of their stellar winds. Eventually the nebula will be entirely dissipated, and all that will remain is a cluster of young stars, all of similar ages and chemical compositions. These are open clusters–as opposed to the vast and ancient globular clusters that haunt the galaxy’s halo–and they include some of the sky’s most brilliant jewels, such as the Pleiades and Hyades, the Beehive, the Double Cluster, and thousands more, of many sizes, ages, and distances.

The Double Cluster photographed by Rob Gendler

Even the stars of open clusters are not destined to remain together forever. They may remain together for tens or hundreds of millions of years, but the lives of stars are measured in billions of years. As open clusters orbit the core of the galaxy, repeatedly passing through the galactic plane, being overtaken and left behind by successive spiral arms, their constituent stars are stripped away from their weak mutual gravitation embrace. Eventually the cluster is entirely dispersed, its constituents becoming the un-clustered field stars that make up most of the galactic disc. Almost all of the stars  that you can see with the naked eye are field stars, each pursuing its own course around the galactic core, forever sundered from their siblings. Lurking out there in the Milky Way are the long-lost sister stars of our own Sun, which we might identify now only by their chemical fingerprints.

Even stars do not last forever. Near the end of their lifespans, with most of the hydrogen fuel in their cores converted to helium, main sequence stars start fusing hydrogen in the shell around the helium core. The star’s interior heats up still further, and the outer layers expand into a vast tenuous envelope. The surface area of this envelope is much larger, in relation to the total energy passing through it, than the star’s old surface. Hence it is cooler, and the light emitted at the star’s surface is shifted toward the red. The star has become a red giant. Arcturus in the constellation Bootes and Aldebaran in Taurus are familiar examples, respectively the third and thirteenth brightest stars in the night sky.

Still larger stars start to fuse helium to carbon and eventually carbon into still heavier elements. These stars may become red hypergiants, so large that they could swallow the entire inner solar system. Betelgeuse in Orion and Antares, the glaring red eye of Scorpio, are red hypergiants, and respectively the eighth and sixteenth brightest stars as seen from Earth.

M27 photographed by Rob Gendler

Now we come to a fork in the road. In small and mid-sized stars, such as the sun, the process of helium fusion proceeds in fits and starts, alternatively heating and cooling the star’s outer envelope. As it expands and contracts, the gas in the outer envelope picks up enough kinetic energy to escape the star’s gravity and expand into space. This process repeats, and star comes to be surrounded by concentric shells of blown-off gas. The gas is still energized by the star’s radiation, and glows as a nebula. This type of nebula is called a planetary nebula, not because it has anything to do with planets (the planets of such a star will have been scorched to cinders or completely eroded by star’s late-stage pulsations), but because they are often round and looked something like planets in the small telescopes of early astronomers. M57, the Ring Nebula, and M27, the Dumbbell Nebula, are two of the best and brightest planetary nebulae. Even tiny NGC 7662, the tiny round glow Brian and I star-hopped to last week, could not be mistaken for anything else. After blowing off most of their mass, the cores of the former giants persist as white dwarfs, which glow not because they sustain fusion but because their matter is heated to fantastic temperatures by gravitational contraction. Even after their planetary nebulae dissipate, white dwarfs may shine feebly for tens of billions of years.

Stars over a certain size, just a few times larger than the sun, have a different destiny. Bigger, hotter, they sustain more rapid fusion, exhaust their hydrogen and other light elements in rapid succession, and then blow themselves apart as supernovae. The cores of the exploded stars persist as neutron stars and black holes. Although supernovae are frequently spotted in other galaxies, there hasn’t been a naked-eye supernova in the Milky Way in centuries. There are some fine supernova remnants, however, diffuse halos of material still expanding outward from the explosions that created them. M1, the Crab Nebula, is one, and the much older and larger Veil Nebula in Cygnus is another.

M1 photographed by Rob Gendler

The matter blown off by dying stars, slowly and gently in planetary nebulae or all at once and violently in supernovae, rejoins the vast, diffuse molecular clouds that clot the galactic disc. Eventually the clouds will be sufficiently compressed, by the pressure waves that form the spiral arms, or by the shockwaves of nearby supernovae, for knots of material to start to accumulate. As the gravitational force of these concentrations pulls in more and more material, they will pass a critical threshold: fusion reactions will start in their cores and they will become new stars, lighting the encircling nebula from which they were born. The circle is then complete.

– – – – – – – – –

It is often noted that we are made of stardust. This is true, but it has become such a cliche that I fear it has lost its visceral impact. Consider: every breeze that has ever cooled you, every bite you’ve ever savored, every caress you’ve ever felt, the blood in your veins, the brain that you think with, the pillow under your head at night, the plastic and metal on which you’re reading this–every atom you’ve ever perceived with any of your senses, and all of others in the universe that you have not perceived, were born in the hearts of stars (except for the hydrogen and some of the helium atoms, which formed in the cooling fires of the Big Bang itself). So, yes, you are made of stardust. And so is everyone and every material thing you know.

And we will be stardust again. In five billion years the expanding sun will envelope the Earth. Our atoms, having been through the planetary cycles dozens  or hundreds of times, and incarnated in countless organisms of which we are but a snapshot, will be blown off with the rest of the crust and outer mantle. For a while we will shine as part of the sun’s planetary nebula, before being dispersed into the interstellar medium. But our constituents will know still greater fires when they are taken up into new stars, and new life when they are incorporated into other worlds.

Ashes to ashes, dust to dust, light to light.

– – – – – – – – – –

That is why I disagree with the estimable Louise Gluck, former Poet Laureate of the United States. When I am packing up the telescope, I don’t see how far each thing is from every other thing. I am still charged by what I have seen, and by the knowledge that I have been a nebula and an open cluster, a red giant and a supernova remnant. Any stage of stellar evolution that I can see in the sky, my atoms have gone through–and will go through again. There is no distance separating me from the stars. There is only time.

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Lunchtime musings

February 24, 2010

In my first six months with my scope I spent most of my time observing the same double handful of objects. I realized that I was stuck in a rut, so one night I took Turn Left at Orion and a red flashlight out with my scope. I figured it couldn’t hurt to try. I decided to start with something I’d never seen before, but which was supposed to be easy–M41 in Canis Major. It was easy–and beautiful! I saw that M46 and M47 were a short distance away, so I tracked them down. And so it went, from one target to the next. I was too excited to linger on any one object. After a couple of hours I’d seen about two dozen DSOs that I’d never seen before. My final targets were M81 and M82. It was the first time I’d ever seen two galaxies in the same field, and it stopped me in my tracks.

In the two years since that night, I’ve been back to all of those objects and many more besides. Almost every time, I notice something that I haven’t seen before. The more times I observe, the more I learn to see, the more I realize how worthwhile it is to linger on each object for a few minutes and give myself a chance to tease out its details.

The objects that I found that night have become like friends. When I am in their neighborhood, I stop by to see what new impressions I will have. And then I go on to meet their neighbors down the street, and the folks on the next block over. Every observing run is an opportunity to improve my skills, to deepen my knowledge of the sky, to explore and to discover.

What kind of relationship do you have with the objects that you observe? Can you remember what they look like when you’re apart? Are they unique individuals or just a long line of warm bodies? Can you point out where they live? Could you get there with a map?

If someone abandoned you for a couple of hours in an empty field on a clear dark night with only binoculars or a spyglass, would that be too much time or too little?