NEWSLETTER OF THE DELMARVA STARGAZERS
May 2005 www.DelmarvaStargazers.Org Vo;ume 11 Number 11
At the
April Meeting ......
Jerry Truitt brought the meeting to order at 7:15 with 29 members and guests attending.
Outreach Saturday April 16 Port Deposit Library- by Jerry Truit
Keith Lohmeyer and I had about 23 adults and 10 children show up at the library on Saturday night. We gave them a short talk and demonstration on
distances, to put things into perspective. I brought a soccer ball which repsresented the Sun. Pin heads represented Mercury, Mars and Pluto,
pepper corns were Earth and Venus in our scale model. A small walnut and an acorn were Jupiter and Saturn, peanuts were Uranus and Neptune.
We had them pace off Mercury in the library, which ran us out of room, and then explained the number of paces for the other planets.
Obviously, this is better done outside but it still gave them a good idea of the scale of our universe. This is called the 1,000 yard universe or Earth as a
pepper corn. I next talked about our universe as a quarter. I explained that if we were on one edge of the Milky Way the other edge would be the coast of California. The nearest star would be two soccer fields away.
Following answering some questions, mostly about how far is this or that, which I'm learning because I brought my Norton Star Atlas and was able to
look things up, we gave our Show on PlanetQuest and the Moon. As you all have reported, there are still lots of great things toview.
I don't think conditions could have been any worse unless it rained, of course. The sky was about as unsteady as it could be; I'm not sure if this was
because we were right on the river or it was just a bad night. On top of that the library is right next to the local bar. I might have read more as a young man
if I'd had that convenience. The bar patron’s headlights, plus outside lighting made it a brutal place to try to view. All that being said, what's out there now is
bright and easy to find. We showed them the first quarter moon, Saturn, Jupiter and the Orion Nebula. They were all amazed and thrilled and every one of
them took the time to thank us. We collected a sign-in sheet and many people expressed interest in attending more events.
Next outreach is Chesapeake City on April 30th at 7 PM. Keith drove 2 hours to come up and help me. It would be great if some people more in the area could help out with these events.
Evening Program by Jerry Truitt
Michael Borgia was slated to speak on the Space Shuttle program for this April's Delmarva Stargazers meeting. Wow! Did he deliver?
Mike's presentation included videos, animations and many technical aspects of the shuttle and the program I was not aware of before. Mike presents highly
technical information in a manner everyone can grasp. He presented a history of each shuttle and the program in general. He also gave us the pros and
cons, pluses and minuses.
Everyone in attendance walked away with a better understanding of the shuttles and what was involved with the building and operating the ships and how
decisions were made with the program. Well is the Space Shuttle program a success or not? That is up to each of us to determine, but those in
attendance have a better basis on which to make that decision.. The bottom line for me is a lot of great space programs were launched on the back of the
shuttles because nothing else in the world could throw them into space.
Keith Lohmeyer gave us a presentation on places or Delmarva Stargazers to observe. He presented us with light maps and ground
maps of Tuckahoe and Black Bird and gave us a lot of information on what we have and how things may look in the near future. A great presentation that
lead to a lot of discussion.
DAS President Billy Westergard attended this month's meeting. Billy has been one of the parties working with Don on the Black Bird site and certainly had
some information to add to Keith's presentation. Billy also wanted to invite all Delmarva Stargazers to the May DAS meeting at Lambert’s Cucina
Restaurant at 1300 Centerville Rd., Price's Corner.
Why would you want to attend a DAS meeting? Besides this being an opportunity to eat great Italian food and enjoy the camaraderie of your fellow
star gazers from the north, they have lined up John Wood from the Goddard Space Flight Center. John is an optical expert and worked on correcting the
Hubble's vision.
We have a lot coming up for our May meeting. Anyone out there up to reporting on the jargon of optical coatings? We also need someone to cover the
Future of Amateur Astronomy. We'll also be planning the next 5 years for Delmarva Stargazers.This is also the time of year to be thinking about what you
want to give back to the club, which is a tricky way of reminding you, nominations for next year's officers will be made at the May
meeting. Clear Skies and hope to see you at Stargaze VI. -Jerry
From the President’s Desk...
April 18, 2005 Greetings! It is 1:30 AM, I am awake, it is clear outside but I am not out there on this clear night looking at the wonders of our universe.
I hope to get my days and nights back in sync soon. The hours between 2AM and 5AM do not have the best TV programming so I have begun filling them
with non-TV activities. Overall, my recuperation is on schedule without any major obstacles; I am currently walking half a mile 3 times a day.
Yesterday, I was reading an old (1987 or 89) Sky & Tel while sunning myself on the driveway (it didn’t have the cool breeze we have been enjoying lately).
There was an article on weather/atmospheric phenomena that I found very interesting. I will not bore you with the technical details…heck, I don’t remember the details. But the gist of the story is that the changing weather patterns of Spring is a great time for observing rainbows, beautiful cloud/sun displays, sunrises and sunsets. You may want to keep a camera with polarizer filter handy just in case you spot something you would like to share with us.
Don’t forget the possibilities of black & white photography when the clouds and sun are displaying their masterpieces in the sky…you may want to use an orange
or yellow filter to enhance the clouds.
Can you believe the weather we have had so far in April? I cannot remember a longer period of clear skies both day and night. What would we do if we lived
in a place where this type of weather is commonplace? We can only dream about such a place because Delmarva will haze up and the weather patterns will
become more changeable. But that is what makes our Delmarva such a nice place to live. The green lawns, forests, farms with wonderful produce, and a usually comfortable climate require lots of rain and clouds. And Mother Nature is usually kind enuf to sprinkle in a few clear nights for us to gaze her celestial wonders.
Most of you know that I have experienced a heart attack and by-pass surgery. I stated in an email to delmarvastargazers@yahoogroups.com
that I would not seek re-election for president of Delmarva Stargazers. Frankly, I dearly love DSG but it is not at the top of my list of priorities in the
near future. I believe it is best for DSG and for me to declare my feelings now so that you have time to think about who you want to lead DSG next year. Nominations for officers will be taken at the May meeting and the election will be during the June meeting.
Immediately after I posted the message on yahoogroups there was a flurry of suggestions on how to “take up the slack”. Most of the suggestions involved
committees. I cannot argue that committees work in some cases – especially when the goal is clearly stated and success is defined as the completion of the goal.
Historically we have not had many formal “committees” but there has always been more than enough resources to man/woman any event we have held.
We may just be one large committee when it comes to execution of the plan. Did you notice the words “goal” and “plan”? Over the years I have informally
surveyed our members for ideas on what those goals and plans should be. You folks are a treasure of information about astronomy. We have not adopted every
idea mined from you in this process but those that have been accepted have been executed very successfully. Basically, I have proposed your ideas to you and you have accepted the challenge and responsibility to successfully execute them. My point is that every organization needs a goto person to make the proposals, to establish goals, and to ask for the assistance necessary to execute. For that reason DSG must have one single person to accept the responsibilities of president.
It is a very rewarding position. I can truly say that I have enjoyed every day of being president for twelve years. You have made it rewarding for me and I thank you for your past support. I know each of you, and I, will support the new president. Look amongst yourselves and nominate the persons you believe are
willing and able to be the “goto” person for DSG president.
Please note I have not mentioned our VP, Sec, Treasurer, Editor of the Star Gazer News, or Aide-de-camp. I will let them speak for themselves about their intentions. So, clean your Naglers, collimate your scope, and lets do some serious stargazing. Speaking of Star Gazing – how about the wonderfully clear skies
the DSG XI were blessed with! Thanks to all who lent a hand to make DSG XI successful. You ladies and gents are just great
See you at the Church May 3rd Don
Kent Blackwell on Easter Island
I’m at an Internet Cafe on beautiful Easter Island in the middle of the South Pacific. This place is awesome. Wow! The southern sky is incredible. I´ve been observing that sky on a moving ship´s platform but have still seen many deep sky objects, including the LMC and Eta Carinae. Here´s a short write up about my trip.
After a hearty breakfast on Friday morning April 8, 2005 Robert Hitt and I set up our telescopes and cameras on the deck of the m/v Discovery cruise ship located about 500 miles from the isolated landmass of Pitcairn Island in the middle of the South Pacific. The sky was mostly clear however some puffy white clouds and a few high cirrus clouds gave us a bit of a scare. It wouldn't take much for one of those clouds to completely obscure a total eclipse lasting only thirty-one seconds. As our ship steamed slowly forward we actually gained a full second of totality from our intended position. The reason Captain Erik Bjurstedt moved his vessel was that he feared clouds would be more prevalent in the original location. Our final position as totality neared was -22 37.879 south latitude and W129 39.27 longitude.
At 10:22 am we saw first contact, as suddenly a tiny bite was taken out of the sun's disk. I've anticipated this for a long time and it was hard to believe the time had finally come to witness this awesome event. As 2nd contact approached at 11:51 am everyone began getting more and more excited. Suddenly the moon slipped completely in front of the sun, revealing a spectacular diamond ring. This was my 10th total solar eclipse and in my experience I've learned not to waste valuable time photographing it. At totality, especially one of this short duration, it's far more important to look at it visually. Believe me, you will never witness anything in nature to match it.
I watched the eclipse through my Orion 4.5" f/4 StarBlast, and the view was nothing short of astounding. For those who have seen prominences through hydrogen alpha filters you may take my word for it that it can't even come close to the vibrancy and glory of those marvelous pink prominences visible during a solar eclipse. I can honestly say I have never witnessed a more beautiful corona or more spectacular prominences than this eclipse. Surely that's because the moon was so much smaller in angular size than it is at longer eclipses. The view was just breathtaking. As I viewed the sun in the StarBlast I was simultaneously photographing it with a 8 Megabyte Canon 20D digital SLR camera riding piggyback, fitted with a 80mm f/6 William Optics Megrez refractor telescope. My gracious thanks to friend Steve Hamilton for lending me this superb instrument. I never took my eye away from the 25x image in the StarBlast telescope, so could only hope the camera caught at least a fraction of what I saw visually.
Viewing and photographing this eclipse was one of them most challenging I have ever undertaken because the swells in the Pacific Ocean reached nearly 10-12', with very high wind gusts. Even at 25x the sun's image would, at times, drift completely out of the field of view, return to the center and then drift out the opposite side. You
have to learn to snap a picture on one of these "returns" to be even moderately successful.
The trip has been wonderful so far , visiting such interesting ports as Papeete Tahiti and the lovely Moorea Tahiti. Our next port was Pitcairn's Island. Pitcairn is famous as the isolated island chosen by the mutineers from the ship HMS Bounty. Reaching Pitcairn remains to this day very difficult because of its inaccessibility and dangerously heavy swells. The 45 inhabitants of this island are surely some of the most isolated people on this planet, and only have electricity a few hours per day. Imagine how glorious the southern night sky is from Pitcairn Island with absolutely no lights, and hundreds and hundreds of miles from any land mass! I could find no flat surface on this mountainous island to set up my 25" telescope!
The next port will take me to Easter Island, truly the most remote place in the world. The nearest inhabited island is tiny Pitcairn over 1200 miles to the west. Easter Island is almost 2,300 miles from Santiago and, in the other direction nearly 2500 miles from Tahiti. To its inhabitants it has always been the center of the world, a fact reflected in its name, Te Pito o Te Henua, meaning "navel of the world", in the belief that they were the only inhabitants. Easter Island is most famous for it's Moai statues. The exact number of Moai is unknown because many lie buried in piles of rubble or beneath the soil at the stature quarry, the estimates vary from 800 to 1,000 and range in size from 12' to 30' tall.
Next year's total solar eclipse will occur through Libya and the Mediterranean Sea. I highly recommend you try see it. Totality at that eclipse will last nearly 4 minutes. I'm already planning my 2006 vacation.
Kent Blackwell kent@exis.net
Moondark for May: Hipparchus of the Greek Islands
Jerry Truitt brought the meeting to order at 7:15 with 29 members and guests attending.
Outreach Saturday April 16 Port Deposit Library- by Jerry Truit
Keith Lohmeyer and I had about 23 adults and 10 children show up at the library on Saturday night. We gave them a short talk and demonstration on
distances, to put things into perspective. I brought a soccer ball which repsresented the Sun. Pin heads represented Mercury, Mars and Pluto,
pepper corns were Earth and Venus in our scale model. A small walnut and an acorn were Jupiter and Saturn, peanuts were Uranus and Neptune.
We had them pace off Mercury in the library, which ran us out of room, and then explained the number of paces for the other planets.
Obviously, this is better done outside but it still gave them a good idea of the scale of our universe. This is called the 1,000 yard universe or Earth as a
pepper corn. I next talked about our universe as a quarter. I explained that if we were on one edge of the Milky Way the other edge would be the coast of California. The nearest star would be two soccer fields away.
Following answering some questions, mostly about how far is this or that, which I'm learning because I brought my Norton Star Atlas and was able to
look things up, we gave our Show on PlanetQuest and the Moon. As you all have reported, there are still lots of great things toview.
I don't think conditions could have been any worse unless it rained, of course. The sky was about as unsteady as it could be; I'm not sure if this was
because we were right on the river or it was just a bad night. On top of that the library is right next to the local bar. I might have read more as a young man
if I'd had that convenience. The bar patron’s headlights, plus outside lighting made it a brutal place to try to view. All that being said, what's out there now is
bright and easy to find. We showed them the first quarter moon, Saturn, Jupiter and the Orion Nebula. They were all amazed and thrilled and every one of
them took the time to thank us. We collected a sign-in sheet and many people expressed interest in attending more events.
Next outreach is Chesapeake City on April 30th at 7 PM. Keith drove 2 hours to come up and help me. It would be great if some people more in the area could help out with these events.
Evening Program by Jerry Truitt
Michael Borgia was slated to speak on the Space Shuttle program for this April's Delmarva Stargazers meeting. Wow! Did he deliver?
Mike's presentation included videos, animations and many technical aspects of the shuttle and the program I was not aware of before. Mike presents highly
technical information in a manner everyone can grasp. He presented a history of each shuttle and the program in general. He also gave us the pros and
cons, pluses and minuses.
Everyone in attendance walked away with a better understanding of the shuttles and what was involved with the building and operating the ships and how
decisions were made with the program. Well is the Space Shuttle program a success or not? That is up to each of us to determine, but those in
attendance have a better basis on which to make that decision.. The bottom line for me is a lot of great space programs were launched on the back of the
shuttles because nothing else in the world could throw them into space.
Keith Lohmeyer gave us a presentation on places or Delmarva Stargazers to observe. He presented us with light maps and ground
maps of Tuckahoe and Black Bird and gave us a lot of information on what we have and how things may look in the near future. A great presentation that
lead to a lot of discussion.
DAS President Billy Westergard attended this month's meeting. Billy has been one of the parties working with Don on the Black Bird site and certainly had
some information to add to Keith's presentation. Billy also wanted to invite all Delmarva Stargazers to the May DAS meeting at Lambert’s Cucina
Restaurant at 1300 Centerville Rd., Price's Corner.
Why would you want to attend a DAS meeting? Besides this being an opportunity to eat great Italian food and enjoy the camaraderie of your fellow
star gazers from the north, they have lined up John Wood from the Goddard Space Flight Center. John is an optical expert and worked on correcting the
Hubble's vision.
We have a lot coming up for our May meeting. Anyone out there up to reporting on the jargon of optical coatings? We also need someone to cover the
Future of Amateur Astronomy. We'll also be planning the next 5 years for Delmarva Stargazers.This is also the time of year to be thinking about what you
want to give back to the club, which is a tricky way of reminding you, nominations for next year's officers will be made at the May
meeting. Clear Skies and hope to see you at Stargaze VI. -Jerry
From the President’s Desk...
April 18, 2005 Greetings! It is 1:30 AM, I am awake, it is clear outside but I am not out there on this clear night looking at the wonders of our universe.
I hope to get my days and nights back in sync soon. The hours between 2AM and 5AM do not have the best TV programming so I have begun filling them
with non-TV activities. Overall, my recuperation is on schedule without any major obstacles; I am currently walking half a mile 3 times a day.
Yesterday, I was reading an old (1987 or 89) Sky & Tel while sunning myself on the driveway (it didn’t have the cool breeze we have been enjoying lately).
There was an article on weather/atmospheric phenomena that I found very interesting. I will not bore you with the technical details…heck, I don’t remember the details. But the gist of the story is that the changing weather patterns of Spring is a great time for observing rainbows, beautiful cloud/sun displays, sunrises and sunsets. You may want to keep a camera with polarizer filter handy just in case you spot something you would like to share with us.
Don’t forget the possibilities of black & white photography when the clouds and sun are displaying their masterpieces in the sky…you may want to use an orange
or yellow filter to enhance the clouds.
Can you believe the weather we have had so far in April? I cannot remember a longer period of clear skies both day and night. What would we do if we lived
in a place where this type of weather is commonplace? We can only dream about such a place because Delmarva will haze up and the weather patterns will
become more changeable. But that is what makes our Delmarva such a nice place to live. The green lawns, forests, farms with wonderful produce, and a usually comfortable climate require lots of rain and clouds. And Mother Nature is usually kind enuf to sprinkle in a few clear nights for us to gaze her celestial wonders.
Most of you know that I have experienced a heart attack and by-pass surgery. I stated in an email to delmarvastargazers@yahoogroups.com
that I would not seek re-election for president of Delmarva Stargazers. Frankly, I dearly love DSG but it is not at the top of my list of priorities in the
near future. I believe it is best for DSG and for me to declare my feelings now so that you have time to think about who you want to lead DSG next year. Nominations for officers will be taken at the May meeting and the election will be during the June meeting.
Immediately after I posted the message on yahoogroups there was a flurry of suggestions on how to “take up the slack”. Most of the suggestions involved
committees. I cannot argue that committees work in some cases – especially when the goal is clearly stated and success is defined as the completion of the goal.
Historically we have not had many formal “committees” but there has always been more than enough resources to man/woman any event we have held.
We may just be one large committee when it comes to execution of the plan. Did you notice the words “goal” and “plan”? Over the years I have informally
surveyed our members for ideas on what those goals and plans should be. You folks are a treasure of information about astronomy. We have not adopted every
idea mined from you in this process but those that have been accepted have been executed very successfully. Basically, I have proposed your ideas to you and you have accepted the challenge and responsibility to successfully execute them. My point is that every organization needs a goto person to make the proposals, to establish goals, and to ask for the assistance necessary to execute. For that reason DSG must have one single person to accept the responsibilities of president.
It is a very rewarding position. I can truly say that I have enjoyed every day of being president for twelve years. You have made it rewarding for me and I thank you for your past support. I know each of you, and I, will support the new president. Look amongst yourselves and nominate the persons you believe are
willing and able to be the “goto” person for DSG president.
Please note I have not mentioned our VP, Sec, Treasurer, Editor of the Star Gazer News, or Aide-de-camp. I will let them speak for themselves about their intentions. So, clean your Naglers, collimate your scope, and lets do some serious stargazing. Speaking of Star Gazing – how about the wonderfully clear skies
the DSG XI were blessed with! Thanks to all who lent a hand to make DSG XI successful. You ladies and gents are just great
See you at the Church May 3rd Don
Kent Blackwell on Easter Island
I’m at an Internet Cafe on beautiful Easter Island in the middle of the South Pacific. This place is awesome. Wow! The southern sky is incredible. I´ve been observing that sky on a moving ship´s platform but have still seen many deep sky objects, including the LMC and Eta Carinae. Here´s a short write up about my trip.
After a hearty breakfast on Friday morning April 8, 2005 Robert Hitt and I set up our telescopes and cameras on the deck of the m/v Discovery cruise ship located about 500 miles from the isolated landmass of Pitcairn Island in the middle of the South Pacific. The sky was mostly clear however some puffy white clouds and a few high cirrus clouds gave us a bit of a scare. It wouldn't take much for one of those clouds to completely obscure a total eclipse lasting only thirty-one seconds. As our ship steamed slowly forward we actually gained a full second of totality from our intended position. The reason Captain Erik Bjurstedt moved his vessel was that he feared clouds would be more prevalent in the original location. Our final position as totality neared was -22 37.879 south latitude and W129 39.27 longitude.
At 10:22 am we saw first contact, as suddenly a tiny bite was taken out of the sun's disk. I've anticipated this for a long time and it was hard to believe the time had finally come to witness this awesome event. As 2nd contact approached at 11:51 am everyone began getting more and more excited. Suddenly the moon slipped completely in front of the sun, revealing a spectacular diamond ring. This was my 10th total solar eclipse and in my experience I've learned not to waste valuable time photographing it. At totality, especially one of this short duration, it's far more important to look at it visually. Believe me, you will never witness anything in nature to match it.
I watched the eclipse through my Orion 4.5" f/4 StarBlast, and the view was nothing short of astounding. For those who have seen prominences through hydrogen alpha filters you may take my word for it that it can't even come close to the vibrancy and glory of those marvelous pink prominences visible during a solar eclipse. I can honestly say I have never witnessed a more beautiful corona or more spectacular prominences than this eclipse. Surely that's because the moon was so much smaller in angular size than it is at longer eclipses. The view was just breathtaking. As I viewed the sun in the StarBlast I was simultaneously photographing it with a 8 Megabyte Canon 20D digital SLR camera riding piggyback, fitted with a 80mm f/6 William Optics Megrez refractor telescope. My gracious thanks to friend Steve Hamilton for lending me this superb instrument. I never took my eye away from the 25x image in the StarBlast telescope, so could only hope the camera caught at least a fraction of what I saw visually.
Viewing and photographing this eclipse was one of them most challenging I have ever undertaken because the swells in the Pacific Ocean reached nearly 10-12', with very high wind gusts. Even at 25x the sun's image would, at times, drift completely out of the field of view, return to the center and then drift out the opposite side. You
have to learn to snap a picture on one of these "returns" to be even moderately successful.
The trip has been wonderful so far , visiting such interesting ports as Papeete Tahiti and the lovely Moorea Tahiti. Our next port was Pitcairn's Island. Pitcairn is famous as the isolated island chosen by the mutineers from the ship HMS Bounty. Reaching Pitcairn remains to this day very difficult because of its inaccessibility and dangerously heavy swells. The 45 inhabitants of this island are surely some of the most isolated people on this planet, and only have electricity a few hours per day. Imagine how glorious the southern night sky is from Pitcairn Island with absolutely no lights, and hundreds and hundreds of miles from any land mass! I could find no flat surface on this mountainous island to set up my 25" telescope!
The next port will take me to Easter Island, truly the most remote place in the world. The nearest inhabited island is tiny Pitcairn over 1200 miles to the west. Easter Island is almost 2,300 miles from Santiago and, in the other direction nearly 2500 miles from Tahiti. To its inhabitants it has always been the center of the world, a fact reflected in its name, Te Pito o Te Henua, meaning "navel of the world", in the belief that they were the only inhabitants. Easter Island is most famous for it's Moai statues. The exact number of Moai is unknown because many lie buried in piles of rubble or beneath the soil at the stature quarry, the estimates vary from 800 to 1,000 and range in size from 12' to 30' tall.
Next year's total solar eclipse will occur through Libya and the Mediterranean Sea. I highly recommend you try see it. Totality at that eclipse will last nearly 4 minutes. I'm already planning my 2006 vacation.
Kent Blackwell kent@exis.net
Sun and Moon Data for May 2005 Tuckahoe MD
38.98°N 75.93°W 5hrWDaylight Time Astronomical Twilight
Sun Moon
Date Twi. Rise Transit Set Twi. Rise Transit Set %
5/1/2005 4:24a 6:06a 1:01p 7:57p 9:38p 2:45a 7:38a 12:38p 45
5/2/2005 4:23a 6:04a 1:01p 7:58p 9:40p 3:19a 8:31a 1:53p 34
5/3/2005 4:21a 6:03a 1:01p 7:59p 9:41p 3:48a 9:21a 3:04p 24
5/4/2005 4:19a 6:02a 1:00p 8:00p 9:43p 4:13a 10:08a 4:14p 15
5/5/2005 4:18a 6:01a 1:00p 8:00p 9:44p 4:36a 10:53a 5:22p 8
5/6/2005 4:16a 6:00a 1:00p 8:01p 9:45p 5:00a 11:39a 6:30p 3
5/7/2005 4:15a 5:59a 1:00p 8:02p 9:47p 5:26a 12:26p 7:38p 1
5/8/2005 4:13a 5:58a 1:00p 8:03p 9:48p 5:54a 1:14p 8:46p 0
5/9/2005 4:12a 5:57a 1:00p 8:04p 9:50p 6:27a 2:05p 9:52p 2
5/10/2005 4:10a 5:56a 1:00p 8:05p 9:51p 7:06a 2:58p 10:55p 6
5/11/2005 4:09a 5:55a 1:00p 8:06p 9:52p 7:52a 3:51p 11:50p 11
5/12/2005 4:07a 5:54a 1:00p 8:07p 9:54p 8:44a 4:43p ***** 18
5/13/2005 4:06a 5:53a 1:00p 8:08p 9:55p 9:42a 5:34p 12:38a 25
5/14/2005 4:04a 5:52a 1:00p 8:09p 9:57p 10:43a 6:22p 1:18a 34
5/15/2005 4:03a 5:51a 1:00p 8:10p 9:58p 11:45a 7:07p 1:51a 43
5/16/2005 4:02a 5:50a 1:00p 8:11p 9:59p 12:47p 7:50p 2:19a 53
5/17/2005 4:00a 5:49a 1:00p 8:12p 10:01p 1:48p 8:32p 2:43a 62
5/18/2005 3:59a 5:48a 1:00p 8:12p 10:02p 2:50p 9:14p 3:06a 72
5/19/2005 3:58a 5:48a 1:00p 8:13p 10:03p 3:53p 9:56p 3:27a 80
5/20/2005 3:57a 5:47a 1:00p 8:14p 10:05p 4:58p 10:40p 3:49a 88
5/21/2005 3:55a 5:46a 1:00p 8:15p 10:06p 6:07p 11:28p 4:13a 94
5/22/2005 3:54a 5:45a 1:00p 8:16p 10:07p 7:20p ***** 4:41a 98
5/23/2005 3:53a 5:45a 1:00p 8:17p 10:09p 8:36p 12:21a 5:14a 100
5/24/2005 3:52a 5:44a 1:01p 8:18p 10:10p 9:51p 1:19a 5:57a 99
5/25/2005 3:51a 5:43a 1:01p 8:18p 10:11p 11:00p 2:22a 6:51a 95
5/26/2005 3:50a 5:43a 1:01p 8:19p 10:12p 11:58p 3:27a 7:56a 89
5/27/2005 3:49a 5:42a 1:01p 8:20p 10:14p ***** 4:32a 9:10a 81
5/28/2005 3:48a 5:42a 1:01p 8:21p 10:15p 12:44a 5:32a 10:27a 70
5/29/2005 3:47a 5:41a 1:01p 8:21p 10:16p 1:21a 6:28a 11:43a 59
5/30/2005 3:46a 5:41a 1:01p 8:22p 10:17p 1:51a 7:19a 12:56p 48
5/31/2005 3:45a 5:40a 1:01p 8:23p 10:18p 2:17a 8:06a 2:06p 37
Moondark for May: Hipparchus of the Greek Islands
| Methodology
first formalized over twenty centuries ago by
the
ancient Greek philosophers.There’s a little
Greek in all star gazers, perhaps even more than just a little. The
fantasies and legends of Greek
mythology are depicted in many present-day
constellations. We use Greek
letters to denote the brightest
of their stars. Professional astronomers employ the mathematics and
analytical m
Hipparchus, born circa 190 B.C. in Nicea in Turkey, is foremost amongst Greek astronomers. He lived on the Dodecanese island of Rhodes and there became the greatest observer of antiquity. He correctly estimated the distance from the Earth to the Moon by parallax. By the same reasoning, he concluded that the sun and stars were immeasurably farther away. He understood the geometry of lunar eclipses and predicted them accurately. Hipparchus noted that the seasons were not equal in length, and he offset the Earth from the center of the solar system to better account for the observation. He ranked stars by their brightness, initiating the system of magnitudes still used today. Although largely lost to history, Hipparchus created a revolutionary star catalog employing equatorial celestial coordinates. His observations were accurate enough that he discovered the precession of equinoxes, the slow westward shift of stars along the ecliptic. Although he could not know that this effect was due to the 27,000-year wobble of the Earth’s axis, Hipparchus realized that any catalog would become outdated with time, and estimated the rate of precession at about 1° per century. No celestial charts survive from the classical Greek era. But Hipparchus’ catalog may have been rediscovered recently in Naples, Italy on the Farnese Atlas, a Roman copy of a Greek statue with an accurately carved celestial globe. Noted astro-historian Bradley Schaefer has just published his analysis of the engraved coordinates of constellations and figures. Accounting for precession, he has determined that the source of the atlas dates from Hipparchus’ time and the latitude of Rhodes and excluded all other possiblities. This remarkable discovery will no doubt shed light on long-standing questions surround this pioneering astronomer and his work. Unfortunately, aside from this recent detective work and a single, surviving commentary on an astronomical poem, none of Hipparchus' work has survived. What we do know of him is recounted in the Syntaxis or as it is more commonly known in Arabic, the Almagest. This text, possibly the most important in all of astronomy, was written some three centuries later by Claudius Ptolemy (ca. 85 to ca. 165 A.D.), a descendent of a Greek family, living in Alexandria, Egypt and a Roman citizen. Although there continues rancorous debate (see Sky & Telescope, May 1984, p. 421 and February 2002, p. 39) about the degree to which Ptolemy appropriated Hipparchus’s work as his own, it is Ptolemy’s catalog, organized by the 48 “ancient” constellations that has come down to us. Of the treatise's 15 books, the last five focus on the geocentric theory of the solar system most closely associated with the author. Ptolemy also published on celestial cartography, sundials, optics and geography. These two Ancient Greek astronomers, Hipparchus and Ptolemy dominated astronomy for the nearly fifteen centuries and were not surpassed until Copernicus moved the Sun to the center of the solar system. While our understanding of the scale and physics of the universe has grown unimaginably since these times, perhaps the best of the Greek Astronomer’s legacy, ancient constellations, still pass above us essentially unchanged, on each clear night. Moondark is written by Doug Miller, published online, and printed in the Delmarva Star Gazers' Star Gazer News. Last revised on 24 April 2005. Text and images are copyright © 2005 by Douglas C. Miller, All Rights Reserved. This material may not be reproduced in any form without prior permission. |
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