Tuesday, February 24, 2009

The Number of Stars

It was a cold winter night with a dark sky and the milky way was clearly visible over our heads. I was in Boy Scouts and my father was helping to orient me to the night sky. I was working toward the Astronomy Merit Badge. Dad had Peterson's Field Guide open to a star chart. He had used some of my mom's red nail polish to paint the bulb of a flashlight so we could look at the chart without ruining our night vision.

As a good parent, my father was trying to point out constellations and the names of certain stars. Like children all over the world have asked for millennia, I just wanted to know how many stars there were. It is not for nothing that the Lord God told his people that their descendants would be more numerous than the stars in the sky. There were a lot of stars out there to see.

Skip forward about 40 years, and I am standing on the back deck of a friend that lives above a quiet valley near San Antonio. (If you are reading this years from now, it was a time before the national Dark Skies movement began, when streetlights and security lights still lit up the night skies and made stars disappear.) As I look up, all I can see from his porch are stars that are second magnitude or brighter. There are not many of them. Here and there in the sky, I can see a star. I can see about half the sky from where I am - what with a house and some trees nearby - but when I scan the sky, all I see is about 5 stars. The kids that come out to the back yard to look through my telescope are fascinated by the view of Jupiter, but it probably never occurs to them to ask how many stars there are... They can easily count to 5 if they have any interest to do so.

Astronomers break down the brightness of stars into "magnitudes". This has nothing to do with the actual brightness of the star, as it would be seen from a standard distance. It has everything to do with the brightness of the star as seen from earth. The magnitudes range from quite bright to very, very dim. It might seem strange, but the brightest stars have the smallest magnitude numbers. Think of first class, second class, third class, to get the idea of what first magnitude, second magnitude, and third magnitude stars mean. (There are even a few stars that are brighter than first magnitude and they have negative magnitude numbers less than one.)

As the sun is setting and the sky starts to get darker, the brightest stars are visible first. Sometimes a planet like Venus, Mercury, or Jupiter is visible first, because they are oten brighter than the brightest of stars. But then the stars start appearing. The first magnitude stars are the first to be seen, then second magnitude, and so forth. If the sky is very dark (far from city lights, and the moon is not out) then most people can see stars down to about magnitude six.

But with bright city lights, or nearby streetlights, the magnitude of visible stars is reduced. At my friend's house, even on the darkest night with no moon, his sky is limited to second magnitude stars.

I became interested in finding out how many stars can be seen at different magnitudes. It turns out that (like almost every question I ask) an answer can be found on the internet. The source I used for answering this question is from: http://www.stargazing.net/David/constel/howmanystars.html.

It turns out that in my friend's sky, when I could see second magnitude stars, there were about 93 stars that that can be seen world wide that are second magnitude or brighter. (Some of these are only visible from the southern hemisphere.) A persistent Boy Scout could memorize that number of stars. That is the reason that for the small slice of the sky I could see from my friend's back porch, all that I could see was a few.

My house is a little further out in the country. From my house, on a moonlit night, I can just barely see third magnitude stars. But that raises the number of visible stars to almost three hundred - three times as many as my friend can see.

When the moon is below the horizon or near new moon, I can see fourth magnitude stars. With the additional darkness I can now potentially see about 900 stars. (Remember that a portion of this number are never visible from Texas - they are too far south.)

If I drive fourty minutes from my home to the Hill Country State Natural Area, incredible stars are visible. From my house, I can never see the band of the Milky Way. But from Hill Country the Milky Way is quite brightly obvious. When I look at the little dipper, I see 9 or more stars. I am in true sixth magnitude dark skies. In this darkness, almost 9000 stars are visible. It is incredible to see how constellations which were too dim to see in town are now like signposts in the sky. I can follow the outlines of the stars and find many more dim objects than I could in brighter skies. It also means that with a telescope, I can see objects that wash out into bright background light in my back yard. In the constellation of Virgo, for instance, there are about a dozen Messier object galaxies that are pretty easy to see in dark skies but which are completely invisible to me in my own back yard.

As I look back across the years to that astronomy session with my dad, I know I must have been looking at a very dark sky with a brightly glowing Milky Way. That is the reason that I was overawed by the number of stars. Thousands upon thousands of them crowded my eyes. I only hope that we find some way to preserve what dark skies we presently have and find ways to bring dark skies back to our cities. Children deserve to be awed by the sky. We all deserve the right to know how small we are and how enormous the heavens are.

Magnitude Cumulative Number of stars
-1.50 to -0.51 2
-0.50 to +0.49 8
+0.50 to +1.49 22
+1.50 to +2.49 93
+2.50 to +3.49 283
+3.50 to +4.49 893
+4.50 to +5.49 2,822
+5.50 to +6.49 8,768

Sunday, February 22, 2009

Learning the Deep Sky with a Messier Marathon


I have been trying to see all the Messier Objects on and off for many years. I read about folks getting together for a Messier Marathon. But it was not until I joined the San Antonio Astronomical Association (SAAA) that I ran square into a group that said they were going to get together as a club on the Messier Marathon weekend for a night of observing.

A number of years ago, staying up all night to look at the stars was one of those things that was "way too hard". That was back when I slept better. These days, in my mid 50s, getting up a couple times a night is just normal. Last fall, with my love affair with the stars just starting, I tried mixing my nocturnal wandering with a star observing session in my back yard. I found two things that early fall morning. First, my neighbor across the back fences never turns his back porch light off. Second, the sky sports a different set of stars in the wee hours of the morning. Of course, I knew that fact with my head. But I had never experienced the fun of looking at the morning stars that would be evening stars many months hence.

One roadblock to the idea of an all night marathon was licked. I found that I could have fun looking at stars in the middle of the night and early in the morning.

But, could I really find all the Messier objects in a night? Last summer, I was thrilled when I was able to identify a dozen Messier objects in an evening of observing. I watched amazed as my new computerized "go to" scope slew its way from one object to another. After a while, the noise of the motors got old as I waited with less and less patience for the scope to move from this object to that one - sometimes turning in a maddeningly slow, nearly full circle just to go from one half of a constellation to the other half! When I converted to a setting circle scope and brought along a long printed page of settings for the evening's objects, I was able to speed it up just a little - but my maximum number of objects for a night was still under twenty.

I found that the secret to going from one object to another quickly was to a) know where the Messier object was, and b) use a Dobsonian reflector with a Telrad finder to point the scope at each part of the sky that contained a Messier object. It was late November when I got this together and began finding objects quickly with a new Orion XT10.

When I joined the SAAA at Thanksgiving, there was already talk about a Messier Marathon in March. I decided I would make a go of it and continued getting my skills and my mind ready for the event.

The first skill was to get good at star hopping from stars that I could see to a piece of sky where there was an object that I could not see directly with my eyes. A great practice object was M1, the Crab Nebula. Even with my urban backyard sky, I was able to find it quite easily. The Ring Nebula (M57) in Lyra was another good easy practice object.

But some of the Messier objects required seeing background stars that were dimmer than third magnitude. Fourth and even fifth magnitude stars are really helpful if a star hop is to be easy and fast. That means practice in an area with dark skies - where 5th magnitude stars are visible. It also meant finding observing times away from the bright moon - for the moon makes all those dim stars disappear even in the best dark sky location. The astronomy "Mecca" I found was Hill Country State Natural Area, ten miles outside Bandara, TX. It was only 40 minutes from my house, and the sky was very black except for a low dome of light in the east caused by San Antonio and maybe Bandera. In the little dipper, I could see stars down to 5.7 magnitude. That meant that the background sky was dark enough to see dim objects, like galaxies - and there sure are a lot of galaxies in the Messier list.

There are other great places within a reasonable drive from my house to see stars. Garner State park is 80 miles away. And if a long weekend presents itself, Big Bend or Ft Davis are only 6 hours away. I also received invitations to two private locations with very dark skies. That is one of the great benefits of meeting fellow amateur observers in a local club.

I have just gotten back from my third overnight during which I practiced the Messier Marathon. I did two practice runs near the new moon in January, and this latest one in February. For each one, I needed to spend the night out in the observing field. Making provisions to camp - or at least to take naps is important to me - I still can not contemplate staying up all night without sleep. I have used a camping hammock twice and last night I slept in the bed of my pick-up truck. Sleeping in the truck has the advantage that I am next to the scope and can get up for a half hour of observing and then jump right back into the warmth of my down sleeping bag.

For last night's session I went to a private field near Fredericksburg, TX. A couple of fellow observers were already set up for the evening when I arrived. This photo shows Yogi with three of his telescopes. As the sun set, we talked about what our goals for the evening's observing would be. (Yogi is the source of the photos in this blog post - thanks Yogi!) After talking for a bit and looking at a very pretty crescent Venus through the white refractor, I went back to my observing area and started finding the evening Messier objects as soon as the twilight let me begin.

I have learned a few lessons about running the Messier list over these practice sessions. First, it is important to have a specific plan for going from one object to another. Having specially constructed charts with Telrad circles already marked on them really helps. Fortunately, a great set of charts has already been created for the Messier Marathon and it can be downloaded directly from the Web.

What I am using is the Star Hopping Guide to the Messier Marathon by Rob Hawley. This can be found at http://www.robhawley.net/mm/. Rob has been producing a version of this file specific to that year's Messier Marathon for several years. As I have used that set of charts (actually last year's version) I have learned a few tricks for finding objects. I have added some lines for triangles that Rob did not put in his guide. I have added a couple eyepiece views for hard to find objects. In short, I have personalized the guide.

However, as I have practiced the marathon my skills have increased. I still remember the thrill of getting all the way through the Virgo cluster of galaxies with firm identification of all the Messier objects. I have learned how to nap for a couple hours and then get up and do an hour's worth of observing a number of times during the night. I have learned to log my findings on a digital voice recorder instead of paper. And mostly I have learned where in the sky all those 110 objects are.

In last night's practice run, I saw 103 objects. That was all the objects that I could see until sunrise interrupted my session. Of the six objects in the Messier list that I still needed for an Astronomical League pin before the session, I was able to log five. That means that I have now seen 109 of the 110 Messier Objects. Whee! In another month, the sun will allow me more of those early morning objects (though it may keep me from seeing a couple of the evening ones that are easy now...) All the SAAA needs to do now is to lock in crystal clear weather for the marathon.

Sunday, February 15, 2009

Astronomical League Observing Clubs

One useful tool I have found this year for expanding my interest in the sky is the collection of "Observing Clubs" sponsored by the Astronomical League (AL). During the last year I became a member at large of the AL after looking through their website and seeing the wide range of activities they sponsor.

Just as a bit of history, the AL is a national organization of local astronomy clubs, associations, and organizations. The league has been around since dirt was young and is a known voice in promoting amateur astronomy and especially amateur observing. The observing clubs, and there are a couple dozen of them, are proposed by local groups and often administered by the local astronomy organizations. The observing clubs all have the general framework of a set of requirements that need to be met to be recognized as having met those requirements. For an old boy scout like me, it seems a lot like the merit badge requirements of the Boy Scouts of America.

This means that an individual who is a member of the AL can set out to show that they have accomplished the requirements and then be awarded a certificate or pin to show they have done so. That is a refreshingly simple idea in a world which is dominated by achievements that require political machinery, gobs of money, or overwhelming popularity. It is a simple idea - no competition, no election, no investment of money - just set out to fulfil the requirements and the award will be mine.

Another aspect of the observing clubs that reminds me of the Boy Scouts is that the different clubs tend to draw me into astronomy on a wider scale than I might be interested in on my own. There are clubs that encourage observation of deep sky objects, planets, double stars, variable stars, and even naked eye observing. There are clubs that focus on use of binoculars, quite a number that require telescopes and dark skies, and there are those that require astrophotography. The chasing of comets, asteroids, and meteors all have their separate clubs. There is even a club - the master observer - that honors amateurs that have earned awards in a number of clubs, including some of the most difficult.

It has been said that there are many observing lists on the internet for the interested amateur to pursue. However, the observing clubs of the AL are a diverse group of clubs at a moderately difficult level. They have the advantage of helping a new observer like me to set some goals with the reasonable chance of achieving those goals.

Over the last 8 months I set out to see the Messier Objects. So far I have seen all but 6 of them. I am looking forward to sending in my logs and get recognition for having done so. Along the way I observed 60 of the Messier objects through my binoculars. That is another club. I am working on the Urban list which is designed for the observer who has less than optimal skies available. I have begun to look at two of the advanced observing lists - the Caldwell and Hershell lists. There are open cluster lists and double star lists and variable star lists that I am thinking about.

One thing that pursuing the AL Observing Club lists has done for my observing is to make me begin to record my observations in a much more rigorous manner than I had before. I think this has improved my understanding of the sky and will be a lasting treasure for me to review in the future. I am now following several of the lists in a spreadsheet on my computer and keeping a logbook entry with a page for each object that I observe for the first time. It has been fun to see that log book getting thicker as the year has progressed.

All in all, I think that the AL observing clubs have made me a better amateur observer in the following ways:

- The clubs have given me goals to focus my efforts to learn more about observing
- The clubs have widened my interests and my knowledge of sections of astronomy that I might not have otherwise been drawn toward
- The clubs have improved my record keeping and this has increased my enjoyment of the sport

Saturday, February 14, 2009

The Stars in their Constellations

The stars of the sky are pretty. Looking at the sky from a dark site while the moon is below the horizon and the sky is clear is enough to amaze the most jaded observer. The Milky Way stretches from horizon to horizon and there are more stars in the sky than a person could ever count. But after a little while, looking at the pretty stars is like looking at pretty flowers. It can be superficial to just stare and say "wow" or "pretty".

The richness of the sky is like the abundance of a large library. When I look at either, I know there is lot there, but start looking more closely requires a system. There is nothing wrong with looking at the sky and saying - "Hey! that little group of stars looks like a baseball diamond. That group looks like a tree." There is nothing wrong with telling your pretty wife that there is star named after her - that bright one right there. But most of us also know that there is a standard set of groups of stars in the skies.

Almost all groups of people have had names for parts of the sky. In historical time, all the great civilizations have had different names for groups of stars. The constellation names we use are actually a lot more recent than is commonly known. The names of many of the stars we use come from arabic sources. The names of many of the constellations come from Greek mythology. Many of the constellations of the far south were named by european astronomers in the 19th century. But it was not until the time of my father's boyhood - the 1930s - that the sky was carved up into boundaries named after the constelations.

It turns out that the boundaries are very useful. Suddenly, with the institution of those boundaries, I can decide to take a closer look at one part of the sky. For me, it's a little like going from an overall appreciation of a field of dasies to the beauty of one individual plant.

Let me give an example. Knowing that there is a constellation called Lyra in the summer sky, I can decide to take a closer look at that little group of stars. I may want to take out a pad of paper and draw the stars in the constellation - just like with dasies, I may want to draw one of the plants or one of the blooms. I might be interested that the bright star in the constellation has a name - Vega - and that it is one of the brightest stars in the summer sky. I can see just a few other stars, but out one end of the constellation is a pair of stars that are about the same brightness - and they have names too - beta and gamma Lyrae.

Just as I might be interested in looking more closely at a daisy with a magnifying glass, adding a little magnification and light gathering power to look at Lyra is fun too. With binoculars, the bright main stars of the constellation are easier to see, and a host of other dim stars can be seen as well.

It also turns out that if I have more magnification and light gathering available through the use of a telescope, that more can be seen. This further study of the constellation yields a beautiful pair of stars visible in binoculars, each of which is a double star (and that division can only be seen with a telescope). This is Episilon Lyrae, the "double double", and it turns out that it is only one of many interesting double stars in the sky. In addition, the constellation holds a beautiful light cloud called the ring nebula right inbetween beta and gamma Lyrae. And the ring nebula is only one of a large group of fuzzy light clouds that are collectively the Messier objects.

This is the reason that I have taken the time to get aquainted with the "official" names of the constellations. Those name and the recongnition of the constellation in the sky is the index to finding all sorts of other beauty.

Here is a list of constellations that are easy to see in the evening sky this time of year (February) Orion is the most recognizable with his belt of three stars, and dangling from his belt are jewels worth looking at with binoculars and telescopes. Canis Major, (big dog) is below and to the left of him. At the heart of the big dog is a beautiful open cluster of stars that can be seen with binoculars and is a marvel with a small telescope. The oval ring of Aurigua contains three pretty open clusters of stars. At the foot of the Gemini Twins is another pretty open cluster. Cassiopeia is a small W or M of stars now in the western sky at dark, but it is chock full of wonderful objects to find - including a little version of the "phone home" ET (or the owl if you like). There is a group of 6 or 7 sisters and an arc of stars between Cassiopeia and the sisters that is full of wonders to behold. One of them, a rogue named Algol, winks down in brightness every 3 days for a few hours and has been doing so for thousands of years.

I hope I might have spurred someone to go out and look at some of the constellations and begin learning a pattern of stars that is unfamiliar. I am still learning some of the dimmer constellations and learning how to find objects in relationship to their dimmer members. It remains ultimately fascinating.

If I would recommend one book for the study of constellations, it would be "Stars and Planets" which is a Smithsonian Handbook. This book has a number of great resources, but among them is a section on each of the constellations and some wonderful items to look at in each one.

Thursday, February 5, 2009

Observing the Heavens with My Eyes

Great peace and great joy come from settling down and gazing at the heavens above. Sunrises, sunsets, slivers of brand new moons, showers of meteors, and brightly shining planets have been favorites of mine since I was a boy.

I have gazed with great contentment at the milky way on moonless nights from the tops of mountains when hiking the Appalachian Trail. I have woken in the middle of the night in my camping hammock and looked up to see that the stars of the big dipper had moved counter clockwise nearly a half circle around the north star since sun down. Seeing that let me know that morning must be near. I have counted the days of a hike, not by the days of the week, but by the phase of the moon. This use of the sky is part of what I have come to call trail time - the relaxation of modern time constraints that allows abandoning a watch and calendar - substituting the signs of the heavens for the minute by minute accuracy of modern life.

The more I use the sky for trail time, the more interested I become in it. The more I live in trail time, the more personal the sky is. The moon's names for its great month long seasons have become important to me. Looking at the traditions of many cultures, I developed names appropriate to the time of year a moon encompassed. A moon begins with a sliver of a new moon just after sunset and waxes (grows) to first quarter and then to full. The first quarter moon is South at sunset and the full moon is East at sunset. It then wanes to third quarter which is South at sunrise and ends with a sliver to the east just before sunrise - a cycle that takes about 28 days.

There are a number of magical times of year for me. First green grass of the spring and apples ripe on the trees are two of my favorites. Longest day in June and longest night in December are also on the top of my list. So it made sense to name those moons green grass, apple, long day, and long night moons. Planting moon, following green grass moon is when tender tomato plants can be set outdoors without much risk of them freezing. In Ohio green grass moon was April and planting moon was in May. Harvest moon followed apple moon, and hunter's moon followed harvest. (In Texas, this system is all messed up, as I plant tomato plants in early March and I never find apple trees in the woods. The grass often does not turn green until late July when the rain starts. All of this has knocked me a little off center as I try to adjust to Texas moons.)

Planets are quirky sky objects that move at their own speeds through the night skies. Venus and Jupiter are very bright - usually brighter than the brightest stars. Mars is a pretty red dot and Saturn a reasonably bright star-like object that wanders slowly from constellation to constellation. Venus slowly moves eastward away from the setting sun to an altitude above the western horizon of several spans of my hand, and then approaches sunset again as the evening star. Then it rises before sunrise earlier and earlier and then approaches the sunrise again. Mercury escaped my notice until this last year. I had mistakenly believed it was a very hard planet to see in the brightness of the sunrise or sunset. Instead it turns out that Mercury is very bright and easy to see either to the East or to the West for several days every six weeks.


Next: Observing the stars, studying the constellations.

Wednesday, February 4, 2009

Location, Location, Location

are the three most important factors when it comes to success, according to many wise counselors.

Location certainly matters when it comes to success in observing the sky. In my back yard observing area, I can only have partial success. I am limited by the trees of the back yard and the roof line of my house. I am limited by the amount of urban light that limits my best unaided observations to magnitude 4. I am limited by the intrusion of light from my own windows and from backyard lights of my neighbors. I am limited by the heat that rises from the shingles of my home, roiling the air with turbulence.

But my backyard location leads to increased probability of success too. My least obstructed view of the sky is to the south. That is good, because as the seasons change this area gives the most chance to see new large swaths of the sky. My urban light problem is much less bothersome as that of friends that live just 15 minutes away toward the center of San Antonio. From their beautiful perch looking over downtown, I can seldom see anything dimmer than second magnitude stars. They have great sunsets, but pretty poor conditions for seeing any of the galaxies on the Messier list. Another great advantage of my location is that by driving an hour west or northwest, I can move below some of the darkest skies in the United States.

My location in near San Antonio also means that I have access to a large number of objects which are not visible from further north. It's true that I can not see the Big Dipper during winter evenings, like I grew up being able to do in Ohio. However, the full tail of the scorpion is very obvious in the summer, along with its treasure trove of Messier objects. From further north this part of the sky is much closer to the southern horizon than it is here.

Observing from a location in the northern hemisphere certainly gives me a different view of the sky than my friends in Australia have. Obviously, I can not see the constellations furthest south and have never observed those two close galaxies associated with the Magellanic clouds.

Another aspect of the northern hemisphere observing location recently occurred to me. A decade ago I needed to find a way to teach my son how to identify the waxing and waning moon. I remembered a scene from Karate Kid - a movie he had seen - in which the master taught his apprentice how to strengthen his arm muscles by waxing his old car. "Wax on - Wax off" with the right hand and then the left was his mantra. I taught my son that the "Wax on" motion with the right hand could remind him that the waxing moon was lit up by the sun on the moon's right side looking south or southwest, and that the waning moon would be lit on the moon's left side.

This fall, as I was looking through different telescopes at the moon, I was trying to determine whether I was looking at the moon's east or west on the right side of the eyepiece and whether the moon's north or south pole was at the top of the eyepiece view. It was clear that with binoculars, the Moon's north was at the top of the view and the moon's east was to the right, just like in a map of the United States. That view differs with different telescopes - a topic complex enough that it is worth writing a blog on the subject sometime in the future.

However, from my backyard it was clear that the first quarter moon was to my south at sunset. As I looked at this waxing moon, its right side was lit by the sun. The moon's north pole was up and its eastern side was to my right.

I asked myself the thought experiment question, "What would I be seeing from Perth, Australia at sunset today?" The answer surprised me after I puzzled through it. I would be looking north at the first quarter moon. This waxing moon would be lit by the sun on my left. The moon's south pole would be up and its eastern edge would be to my left. Everything about the view would be completely backwards from my northern hemisphere viewing area.

This understanding may be completely obvious to southern hemisphere observers. They are used to having to translate texts to their point of view. But it was an understanding that had escaped me for the first 55 years of my life. It was a good feeling to finally come to a new understanding of a very basic idea.

Tuesday, February 3, 2009

The Sun, the Seasons, and the Day


I enjoy a good sunrise.

After a long winter night in the woods, seeing the sky begin to lighten and then seeing the sun rise above a hill to warm my bones is a fantastic time - linked in my mind to birth and resurrection. The beginning of the day is the beginning of life all over again. Daybreak is the resumption of goals and the fulfillment of the dreams dreamed the night before.

A few years ago, I realized just how different sunrises are as the year progresses. Sitting in my east facing office, the sunrise of late December is two spans (the hand held at arms length - the distance from little finger to thumb, with the fingers spread) south of East. The sun follows an arc that appears makes the same angle with the horizon no matter what time of year, but it begins further south in the mid winter. That makes the day shorter and the height of the noon sun lower at this time of year than any other time of year.

On the day of an Equinox, the first days of Spring and Fall, the sun rises directly to the East. The day is longer, the sun at noon is higher, and the average daytime temperature is rising. At the Summer Soltace, the sun rises two spans north of East and the day is at its longest. I have watched this progression from my sun room in Ohio and from my office in Texas. For me, it is a rite of yearly passage to observe the rising of the sun.

I also enjoy the daily passage of the sun from its rising to its noon to the south and back to its setting. A couple years ago, I enjoyed almost daily trips to a tipi in my Ohio backyard. I had it set up with the door facing East. In the winter, I would often traipse down to the tipi before sunrise and start a fire in the central fire ring. Then as the sun rose I opened the door flap and enjoyed the fresh sunlight streaming through the doorway onto the figures I had painted on the tipi liner. It was a quiet time that encouraged me to pray and to think about the day to come.

In that peaceful time, I came to appreciate the daily circle of life. The brilliant red rays of the sunrise became linked to the East and with the beginning of life as well as a day's occupation. Almost automatically East became linked in my mind to spring and the beginning of the year's cycle of growth and harvest. As the sun traveled southward toward noon, I thought of the South as being the place of warm summer, adolesence, growth, greenness, and summer. Sunset in the west reminded me of the accomplishment of adult life and the Fall of the year. I thought of the moon as being born to the West, where each new moon begins. North became the place of night, rest, the respect of elders, a time for reflection, dreaming, and planning for the day to come. North was a time for the brilliant stars that slowly wheel their way across the sky.

Southern hemisphere readers will realize that all these illusions are all exactly backwards for observers south of the equator. If you have tipis, you are welcome to come to your own conclusions and reminders of the lessons of life in your own way.

Coming back to astronomy in the years of my elderhood seems natural. It is a time to appreciate the night more and to think more about the eternal. It is a time to discover what has remained hidden during much of my life. It is a time to revel at the enormous beauty of the creation and to think about the wonderful hugeness of the creation and my small and fleeting part of it.

Monday, February 2, 2009

Comet Lulin - Beginning of February

There is a comet in the morning skies which is within the reach of anyone with a telescope. This is the first bright comet which has wandered into the inner solar system since I became interested in astronomy again.

I first picked up Lulin when it was just above the left two stars of the fan of three stars above Scorpio. (Scorpio is one of the few constellations that I think looks like its name sake.) It has now moved further up in the sky and is approaching one of the brighter stars in Libra. The comet is moving faster and faster against the starry background as it approaches earth on its way back out from the sun.

Just the other day, I did a drawing of the comet. Here is the diagram showing where the comet was that morning:

And here is a drawing from the eyepiece of my telescope. Everything in the telescope is reversed, up for down and left for right. If I turn the drawing around, it would look like a binocular view (which is right side up and correct left and right.)


By the by, the way I made these drawings was to make a drawing with white paper. I made the stars very black with a Sharpie marker and the rest of the writing and drawing was done with a pencil. I took a photograph of the drawing and then used Microsoft Paint to reverse the colors. It is a simple way to make drawings which are correct for black and white.

The motion of this comet is somewhat unusual in that it is traveling in the plane of the planets, but backwards. That is, while all the planets and most comets are traveling around the sun one direction, Lulin is bucking all that traffic. There is still some debate about why this might be, and I will be interested in seeing how the astronomy community comes to an understanding of this unusual comet.

I saw a very nice photograph of the comet on the Astronomy Picture of the Day site this morning. It clearly showed the dust trail on one side of the comet (it was on the left) while the particle trail was being streamed out in the opposite direction (toward the right) beyond the comet.

I have observed the comet from my Helotes backyard a number of times with my 10 inch reflector. I have not been able to see the comet with binoculars from there yet. When I was up near Fredericksburg early Saturday morning, I thought that Lulin was getting brighter, and with the dark skies there I was able to see the comet with binoculars.

The last time I went outdoors to see a comet was Halley's comet back in the mid 1980s. That comet was an easy visual one. There have been a number of very nice visual comets since then, but I was involved in other hobbies and projects and never took the time to find them. Given that, it has been fun to follow this comet through the morning skies. I am hoping that it reaches naked eye visibility within the next couple weeks before it starts fading later in February.

Dark Skies Begin at Home

Recently I wrote to my city of Helotes, Texas to find out what the lighting ordinance might say about lights in my neighborhood. This all began because, in my small backyard observing area, one of the neighbor's lights shines into the back yard over my fence every night of the year. I wondered if there was any legal basis for my asking that neighbor to shield their light.

I was surprised to find out that in the summer of 2006, the city had passed a very well written ordinance requiring compliance with lighting standards that are friendly to dark skies. All new installations after that date must be in compliance - which essentially requires full shielded lights. All grandfathered lights must come into compliance by 2012.

Like most houses on my street, I had clear glass "carriage light" type fixtures at my front door and above my address marker on the front of the house. I thought that it would be interesting and perhaps important to change out my fixtures. If I was not willing to take the time and shell out the money for new fixtures, there was no hope that I could get others to begin taking this challenge seriously.

I looked through the offerings at the local Home Depot hardware store. Though they had scores of outdoor fixtures displayed on a large wall, only one seemed to meet the fully shielded requirement. I brought this to the attention of the supervisor of that section of the store and he said that their buyer would be meeting with them later in the month and that he would push for more fully shielded lights. I think that is a good idea, because by the lighting ordinance, any lighting fixtures purchased to be installed in Helotes are already required to meet the requirement of the lighting ordinance.

Next, I drove to the nearby Lowe's Hardware store. Here I found about a half dozen fully shielded lights and several others that meet the requirement if they are installed under an overhang, such as the alcove at my front door. I bought two fixtures. One, pictured at the beginning of this entry was less than $20 and is fully shielded. I think it works much better than the light I replaced for the purpose of making my address visible after dark. It does not shine any light outside my property lines.

For the replacement of the light under my front door overhang, I chose a fixture which shields horizontal light. It does not meet the requirement of full shielding above the horizontal, but with the roof above it, it meets standard and no light is transmitted above the horizontal. (This fixture could be brought into compliance with the fully shielded requirement by installing a baffle in the upper portion of the light to restrict upward light.)

My next projects to work toward dark skies will be to contact my Home Owner's Association to get the broken street light on the corner nearest my home replaced with a fully shielded light. The swimming pool lights a block away are of the old-fashoned barn light design. I will talk with the Association about those lights too.

Some new construction in the city has lighting which does not meet the lighting ordinance. Worst among these lights are "pack lights" installed on the side of the buildings which radiate very intense light horizontally. I plan to talk with the building inspector about these lights.

Maybe I will find a way to invite my neighbor over to my backyard observing site and politely mention his bright white-blue light that shines in my backyard all night every night. God give me the grace to be nice and friendly.

Sunday, February 1, 2009

Observing at Cat's Meow Star Field


What a fantastic night I had on Friday evening and Saturday morning!

At Hunter Scott's invitation, I drove up to his place on Friday afternoon for a night of Messier Marathon practice. I knew the moon would be up until about 11PM, but most of what I wanted to observe was going to be up after midnight.

Despite his commitments to his arriving overnight guests, Hunter took time out of his late afternoon to show me the observing field and make me feel welcome. Ron Weber had also given me permission to use his trailer on this cold night. My intent was to outdoor camp, but it was nice to know that I had an escape plan if I started to get cold on a night that was forecast to drop to the mid 20s.

I found a great place to hang my hammock 20 yards off the end of Ron's camper between two oak trees. First dibs claimed on this place during the club Messier Marathon in March! It was a great place to get some shut eye on and off through the night.

I also took a long walk around the star field, judging how high the trees were above the horizon. I took a look at a far corner of the property, where Hunter said he may put an observatory one day. In the end, I chose a spot closer to the center of the star field. I set up my Orion XT10 and parked my truck with the tailgate near the scope to work as an observing table. I put the cover over the scope to keep dew and birds off the optics.

The sun was still up as I cooked my noodle dinner on the picnic table and settled down for a winter's nap about 5 PM. The sun was still up, but trees shaded my camping spot and I had not had an afternoon nap. So I was able to get right to sleep.

I woke at about 0130 Zulu time (730 PM) with the moon still way above the horizon. I spent a few minutes planning how to find the Andromeda galaxy and a few other early marathon objects only using landmarks over these objects. (I usually use the great square of Pegasus to find the Andromeda Galaxy, and instead found a way to use Perseus and Algol to point to the Andromeda and M33 pointers.) After a half hour of goofing around with these, I went back to bed.

My next observing session began about 0545 Z and lasted until about 0730. The temperature had dropped to about 30, but fortunately there was no wind. The sky was in perfect shape with no clouds and very easy magnitude 6 viewing. The eastern light domes were all very small and easy to deal with. The western constellations were just about where they will be at the beginning of the marathon. Even though it was about midnight local time, I could not see M74 or M77 through the thick atmosphere, despite knowing that I was looking at exactly the right spot. (I had seen them earlier at my evening observing session.) M31, M32, M110, and M33 were all easy. I began working my way through the evening MM list and had no difficulty with the CAS objects, the objects near ORI, TAU, GEM, and AUR.

The open clusters of CMA and MON worked out very well. I had puzzled through them at Garner SP the week before. I forgot M48 when I thought it was part of the M46-47 group. That was the only object on the list that I should have easily been able to find and did not log for the night.

For the second time, I used a dictaphone recorder to do logging. It was much easier than trying to write my observations, especially in getting details down about objects.

By the time I had gotten to this point, my toes were pretty cold and I wanted to wait until UMA and LEO were further up in the sky to continue. So I set an alarm for 3:30 AM local time and laid back down in my hammock for another winter nap. It took a long time to warm my feet up in the sleeping bag as it was about 28 degrees. My set up was plenty warm for sleeping, but rewarming was not easy. I found myself warm in my core, but my feet stayed cold. I even took my socks off and used my legs to warm my toes. Any way, by the time my alarm went off I was toasty warm and ready to get up and see more stars. But for some additional help with warming, I turned on the gas heater in Ron's trailer before starting the next session which lasted an additional two hours.

This session was from 0930Z to 1130Z. During that time, the largest part of the observing was of faint galaxies. Before starting the galaxy sweep I warmed up with the two open clusters in CAN. Then I went to the faint fuzzies with with the LEO quintuplet and then moved on to the 12 Messier objects in the big dipper and CVN. All but M40 are galaxies. BOO next got my attention with its trio of objects, and the globular clusters M3 and M53 were a little odd after all those faint fuzzy galaxies.

Of the 19 objects in the VIR, COM and HYA area, only one is a globular cluster. Using the excellent eyepiece charts by Rob Hawley, I was able to make my way through the Virgo cluster of galaxies another time without a hitch.

THen I picked up the "early summer objects" that I could - including M13, M93, M5, M12, M10, M14, M57, M58, M29, M39, M80, M4, and M107. By then I was cold again and I retreated to the trailer to warm my toes next to the hot air vent for about 20 minutes.

Dawn was approaching, as I could see the sky beginning to get lighter in the east at 1200Z. In my rush, I tried to see what else I might be able to see. I picked up M27 and M71 through a break in the tree line. M19, M62, M6, M7 (in the tree line) M8, M20, M21 were seen with binoculars. as I hurried the last few minutes of reasonable seeing. I could have seen M23, M24, M16, M26 and M11 if I had not been so time pressed with the dawn. And so it finally was over.

I ended up seeing 90 Messier objects, none of which were new for me, but 14 objects that I saw with binoculars were new on that list. I now have well over the necessary 50 binocular messier objects to apply for that Astronomical League pin.

I retired to sleep another couple hours until the sun was lighting the whole world all around me. It was about 8 AM.

Then it was just a matter of packing up. I turned off the gas and the thermostat in Ron's trailer, packed up my camping gear and scope, and as quietly as I could I drove out Hunter's front gate. In Fredericksburg, I stopped for some coffee and breakfast and then drove home for a hot shower.

Fun? You bet! Rewarding? Oh yes!.

Again many many thanks to both Hunter and Ron for their invitations. I hope I left everything pristine and looking like I had never been there. I want to get another invitation after all.

Dark Skies,

Risk