here is a bit of info for those that care...
The controversial interpretation of the Hill "star map" conducted by Marjorie Fish includes the sun and 15 nearby stars. These stars make an ideal case study for stellar age determination as described in this article. For further details specifically about this map, see in Focus and the December issue.
Commentary
Editor's Preface
The lead article in the December 1974 issue of ASTRONOMY, entitled "The Zeta Reticuli Incident", centered on interpretation of a map allegedly seen inside an extraterrestrial spacecraft. The intent of the article was to expose to our readers a rare instance where astronomical techniques have been used to analyze a key element in a so-called "close encounter" UFO incident. While not claiming that the analysis of the map was proof of a visit by extraterrestrials, we feel the astronomical aspects of the case are sufficiently intriguing to warrant wide dissemination and further study. The following notes contain detailed follow-up commentary and information directly related to that article.
The age of our own sun is known with some accuracy largely because we live on one of its planets. Examination of Earth rocks -- and, more recently, rocks and soil from the moon -- has conclusively shown that these two worlds went through their initial formation 4.6 billion years ago. The formation of the sun and planets is believed to have been virtually simultaneous, with the sun's birth producing the planetary offspring.
But we have yet to travel to any other planet -- and certainly a flight to the surface of a planet of a nearby star is an event no one reading this will live to witness. So direct measurement of the ages of nearby stars -- as a by-product of extrasolar planetary exploration -- is a distant future enterprise. We are left with information obtained from our vantage point here near Earth. There is lots of it -- so let's find out what it is and what it can tell us.
When we scan the myriad stars of the night sky, are we looking at suns that have just ignited their nuclear fires -- or have they been flooding the galaxy with light for billions of years? The ages of the stars are among the most elusive stellar characteristics. Now, new interpretation of data collected over the past half century is shedding some light on this question.
Computer models of stellar evolution reveal that stars have definite lifespans; thus, a certain type of star cannot be older than its maximum predicted lifespan. Solar type stars of spectral class F5 or higher (hotter) cannot be older than our sun is today. These stars' nuclear fires burn too rapidly to sustain them for a longer period, and they meet an early death.
All main sequence stars cooler than F5 can be as old or older than the sun. Additionally, these stars are also much more likely to have planets than the hotter suns.
There are several exciting reasons why the age of a star should be tracked down. Suppose we have a star similar to the sun (below class F5). If we determine how old the star is, we can assume its planets are the same age -- a fascinating piece of information that suggests a host of questions: Would older Earthlike planets harbor life more advanced than us? Is there anything about older or younger stars and planets that would make them fundamentally different from the sun and Earth?
Of course we don't know the answer to the first question, but it is provocative. The answer to the second question seems to be yes (according to the evidence that follows).
To best illustrate the methods of star age determination and their implications, let's select a specific problem. "The Zeta Reticuli Incident" sparked more interest among our readers than any other single article in ASTRONOMY's history. Essentially, that article drew attention to a star map allegedly seen inside an extraterrestrial spacecraft. The map was later deciphered by Marjorie Fish, now a research assistant at Oak Ridge National Laboratory in Tennessee.
In her analysis, Ms. Fish linked all 16 prominent stars in the original map (which we'll call the Hill map since it was drawn by Betty Hill in 1966) to 15 real stars in the southern sky. The congruence was remarkable. The 15 stars -- for convenience we will call them the Fish-Hill pattern stars -- are listed on the accompanying table.
Since these stars have been a focus of attention due to Ms. Fish's work and the article mentioned above, we will examine them specifically to see if enough information is available to pin down their ages and (possibly) other characteristics. This will be our case study star group.
click here for pics
In my work I was able to verify the findings of Marjorie Fish in terms of the astronomy used.
Ruff
