Steve’s Virtual Planet

Star names & their origin - part two

A few posts ago I started to take an overview of Star names & their origin. As I said at the outset, this series will be more of a reference post since the literature on this topic is vast and not worth trying to recreate. The adage I follow to all the knowledge in the world - “you don’t have to know everything about everything, you just need to know how to locate it”. Anyhow, back to the topic of star names, in this case, the mysterious world of Chinese astronomy and Indian astronomy.

If you follow the links above, you will travel back to the early days of Asian astronomy, although, much of it is rather obscure. The historical record is harder to penetrate but still enough is known to inspire a sense of wonder at the precision of these earlier sky watchers. In both China and India, scholars looked at the sky above and continued to attempt to connect the world below. Their religious, astrological, mathematical and philosophical disciplines were intertwined with their viewpoints of the heavens.

As with many cultures around the world at various times, the practical nature of far eastern astronomy had a lot to do with creating and refining calendars. However, an even greater effort was put into creating some of the earliest star maps and catalogs. The results were usually hand printed with colorful illustrations and icons. The star maps are especially valuable since they occasionally notate a rare transient observation like a comet or even supernovae.

When you scan the link pages above, look carefully at the dates and compare them to the times of the Arab and Greek astronomers. Also see how there was a rich exchange of knowledge between Indian, Chinese and Islamic astronomers for many centuries. Some of this was bound to have had an eventual effect on the burgeoning Renaissance that would develop in Europe.

I’ll leave it to you to drill down into hyperlinks and go exploring back in time. I promise that along the way you will find yourself marveling at the skill and wisdom of those past astronomers. Enjoy the journey!

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Summer Solstice 2013

How time flies (so to speak)! The year is almost half way complete looking at our modern calendar. The Summer Solstice occurs this Friday, June 21, and that will signify the longest day of the year. So starting Friday, the days get shorter and the nights longer. That is some consolation to a star gazer. But, of course, for centuries human kind has known the cycle of the seasons was at its midpoint, even if they didn’t have a calendar hanging on the wall. And they knew that by .. well .. sky gazing.

It always fascinates me how we as a species have developed ways of keeping track of the year over the eons with some kind of calendar. Using the sky as a source for a calendar has a human legacy that began before written history. Use the link to solstice below and you can begin to follow the path through human culture and exploration back to the predawn of civilization. Our Sun has been with us every day and will continue to light our way for many millennium to come. And it’s constant return (fortunately) day after day has left its mark on us.

Just as important as a calendar is the astronomical event itself, born from our position in relation to our star, The Sun. The word solstice comes from the Latin, meaning “sun, to stand still”. This happens twice a year, once this week, and again on December 21st, more or less. Of course, this has been going on for over 3 billion years! It’s not really news but there has been a long tradition of watching the sun and its position in the sky. And over the centuries, we have managed to understand the motion of the Earth around the Sun, even if you don’t yet fully understand the Sun itself.

Next time you’re outside watching your shadow, remember that light, those photons, came from our Sun. The rock you stand on is held in a consistent orbit thanks to the gravitational pull of the Sun. Almost everything around us benefits from the energy that bathes the Earth, the clouds that rain on us, the food we eat. So, celebrate on Friday! It’s Sun Day!!

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Mercury rising!

The first stone from the Sun, Mercury, is coming into view in the evening sky. On June 10th and 11th Mercury will be joined by the 2 (and 3) day old moon with Venus brightly at it’s flank slightly to the North. By June 12, the planet will be 24 degrees from the sun and up high enough to (hopefully) clear the trees here in suburban Atlanta. Around June 19th, Mercury will be really close to Venus.

Mercury will linger in the very middle of the constellation Gemini for most of June. If you can sight Venus in the twilight hour as a start, then you can get you bearings. There are several sky charts online with links below. However, I always suggest using your SkyMap chart to get started. Then go to the the SkyView Cafe online tool to get a pinpoint layout of the western sky. By tweaking the date and time and using a 45 degree view to the west, you will be able to get a large image of the western sky that you can print.

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Working at Fernbank Science Center

This past week marked the beginning of a stint as a contract assistant at the Fernbank Science Center. I have been a volunteer since August 2005 and I now have the privilege to officially be part of the staff for the summer. It is a great opportunity to continue my work in astronomy outreach and it’s even more fun than before.

I’ll be helping out in the planetarium but these days we have the full dome digital projector to present the planetarium shows and it has made a real big difference. The audiences are loving it! The best part is that we are doing a live “Sky Tonight” presentation along with the main show. This means I get to use the Zeiss Mark V star projector again, the best way ever to map a crisp star field across the dome.

The summer observing season has gotten off to a great start with Saturn taking center stage for the next 10 weeks. I’ll be “up in the dome” on these warm summer nights, my “classroom with a hole in the roof!”

Clear skies all!

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Ancient Astronomers of Chaco Canyon

This is another post about Rich Holtzin’s blog, this time covering the amazing archeological site of Chaco Canyon in New Mexico. There will be more blogs on this since it is a growing interest of mine. But for now, here  re the links to his two part series on Chaco. Sit back, read and be amazed. Enjoy!

Chaco Canyon

Part 1

Part 2

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Archeoastronomy - An introduction

I am always on the lookout for interesting articles on astronomy and recently I came across a series on archeoastronomy by Rich Holtzin. He has been on an extensive tour of the South West United States since late last year and has spent quite a lot of time visiting archeological sites of astronomical significance.

The links below are his first blog entries on the topic. Unlike many blogs, they are very extensive, detailed and filled with photos. I’ll be posting more link to Rich’s blogs, covering Chaco Canyon and other important location throughout the Four Corners area.

Intro to archeoastronomy:

Part 1

Part 2

Part 3

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Star names & their origin - part one

This is going to be a reference post that can help you get started into a very deep subject. There are so many different paths one could take when exploring the history of star names and their respective constellations so I’ll try to just set you up and you can take it from here. This post covers what I call more “classical” star names since many of the names we use today come from this tradition. I’ll have more posts in the series in the coming months covering the less well known star names.

Even though there is a lot of literature covering what I would call the classic star name history (Greek and Arabic especially), one should also look to the Chinese and Indian cultures for some very early developments. You could also look to the Anglo Saxon times for connections to the sky from places like Stonehenge. Then, travel west across the Atlantic and examine the rich culture of the Meso Americans like the Maya. Finally, there are also a number of great star stories, myths and traditions throughout North America, such as the native pueblo Indians like the Hopi, and the Pawnee of the great plains. All of these cultures have contributed their own names for the star in our sky.

I have begun reading more about the Southwest American Indian cultures such as those that lived in the 7th through the thirteenth centuries. I hope to follow that thread more in the future in what I hope will be a section on American Archeoastronomy. I’ll have a future post on this coming soon. Here is a useful link on archeoastronomy if you’re interested in a primer on the subject.

The Wikipedia links below are a good starting point for researching star names from the Greek, Latin and Arabic traditions. And watch for the upcoming posts in this series.

Wikipedia: Star observation history

Wikipedia: History of the constellations

Wikipedia: Star Names - Their lore and meaning

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How stars shine

One of my previous posts considered the use of the terms magnitude and size when talking about a star. Well, as I pointed out, when we are talking about stars, one has to start with the term “mass”. Everything depends on the stellar mass. That is the starting point when trying to understand all of the other physical properties of any star. The star’s initial mass sets the course for the life of that star and even it life span.

These links get you to the heart of a star quite literally to detail a star’s radiation and stellar structure. Star’s shine because of the enormous amounts of energy released in their cores due to nuclear fusion. The star’s mass, in combination with the force of gravity and the electromagnetic and nuclear forces, provides the means for a star to brightly shine for millions and even billions of years.

Without duplicating all that is written already about stars, these additional links take you to more of the Wikipedia pages on stars and their complex characteristics.

Wikipedia: Star

Wikipedia: Stellar_evolution

Wikipedia: Star_formation

Wikipedia: Stellar_structure

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Hercules and it’s mythology

The sky has been painted for centuries with creatures and symbols alike and we can enjoy this history through the mythology of the heavens. Constellations reveal patterns in the sky that have been interpreted by many societies and peoples near and far. The stories of the ancient Greeks are perhaps the most familiar to us and their myths encompass a whole family of characters.

One of the great mythical figures is Hercules, although, his legend stems from stories originally crafted by the Babylonians. In any case, you can follow up on his great adventures and his many labors at the link below. Like all of the great constellations, the story of Hercules has many angles depending on which part you’re reading and which society it came from.

Follow the link below to begin your journey into the Greek mythology of Hercules. And check out the hyperlinks within the page to other famous characters in the pantheon of superheroes!

Wikipedia - Hercules

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Winter Colors

This time of year is always a little bit of a challenge when it comes to listing good targets for public observation sessions. The last of the globular clusters have moved off, the galaxy scene is sparse and if the moon isn’t up all you can hope for is a nice big fat planet. Aside from the planets, what does one do to tickle the imagination of the public?

One way I have found is to use color as a theme. It’s a tricky topic since our eyes don’t perceive color very well in the first place. But then again, this is always a good opportunity for teaching a little physiology. I use my standard short explanation of how our eyes work to explain how to better enjoy the view through the telescope, regardless of the color we perceive.

Major stars like Aldebaran in Taurus and Betelgeuse in Orion are a good start. Most people see a bit of orange in both of these big stars. Rigel is in the immediate area in lower Orion, so it can serve as the quintessential “bright white” star (not to mention a bonus companion that makes it a double!). Then, by merely tilting the telescope down about 5 degrees into Lepus and navigating slightly west, we get to Hind’s Crimson Star. See my recent post on this lovely red carbon star.

The Orion Nebula is another possibility even if you don’t have a large aperture ’scope. I usually have my laptop running a program like Stellarium so I can show an image in color to augment the actual view through the telescope. Through the 36 inch cassegrain, I sometimes pick up a little color and some of the yonger visitors also do. In any case, I usually promote the idea of investigating this wonderful nebula online, since it’s probably the most photographed object in space. But this helps get the point across that even with the limitations of our eye biology, we have great resources for images to pick up where our eyes leave off.

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