Most of the stars live in the LA area, so that puts them about 1000 miles or so from where I live. Your mileage may vary…
Well, someone had to say it, didn’t they? Anyway, seriously …
That used to be the case, but that was before the Hipparcos satellite (mentioned by Squink above) did its job.
From the ground, reasonably accurate parallaxes are limited to about 100 parsecs, or some 326 light years. But from space, above the distorting atmosphere, Hipparcos was able to measure parallaxes much further out. I’m not sure what its distance limit was, but Betelguese was within it. Hipparcos also had a limit on the brightness of the stars it could see. IIRC, it was somewhere around magnitude 13. Anything dimmer than that it couldn’t see to do a parallax on.
I believe someone (ESA?) is planning a followup to Hipparcos. It’s supposed to be more accurate as well as having a lower limiting magnitude. Other than that, I don’t know anything about it. I can’t even remember its name.
Interesting! Is there, by any chance, any plan to send out ‘parallax probes’ that would travel further out into the solar system to get a wider baseline? The parallax out between the orbits of jupiter and saturn would have to be more noticeable than from the earth.
(I realize that there would be problems with this scheme, controlling the probe accurately at such a distance, the fact that a more distant orbit means a longer time between measurements, etcetera.)
PS: Several years ago I was working on a science fiction story set in the late 21st century, after a fluke accident had led to the discovery of a ‘hyperspace drive’. As people started to explore interstellar space, developing precise distance figures for the stars became more important to the task of drawing a map of our area.
On Arabic star names: Most of the star names we use today come for the Almagest. The Syntaxis of Ptolemy, written circa 130 CE in Greek, was basically the synthesis of all Greek astronomical knowledge of the time: their cosmology, star charts, etc. It was translated into Arabic, commonly known by the shortened title Al-Majisti, ‘The Greatest,’ in the 9th century, and studied for centuries, but all copies in the original Greek have been lost. Around 1410, it was translated back into Latin as the Almagest, giving us all the mangled transliterated star names we know today.
I spent two years in Saudi Arabia back in the early 80’s and developed an appreciation for why astronomy was so well developed there.
There were no clouds.
Seriously. There were only a dozen or so nights a year with any significant cloud cover. Every evening I would go out for a walk in the desert. The clarity of the sky was spectacular, and the changes in the sky were impossible to miss - some of the “stars” changed positions relative to the other stars, and unlike the moon some of them reversed course from time to time. Over a few months the effect was like dancing stars.
And the landscape was flat as a pancake as far as the eye could see, but finding your bearings was simple with a sky that quickly became as familiar as the back of your hand.
Intimate familiarity with the night sky is a wonderfully natural experience there.
Sorry, but I don’t understand why the Hipparcos satellite is such a help in measuring parallax. If I understand the concept correctly, the diameter of the earth’s orbit is not all that large compared to the immense distances of the stars, so it is not very useful in measuring distances via parallax. The link to the Wiki article on the Hipparcos satellite says it’s in a geosyncrynous orbit no larger than 22,000 miles from the earth and down to as little as 300 miles. That’s really puny. So how does it help? Is it just a matter of being above the atmosphere and making more accurate measurements? Why was this satellite such a big deal in making these measurements? I thought I was going to read that it swung way out in the solar system and measured the distances to the stars from vantage points like the orbit of Mars or something.
I’m not sure, but I’d imagine that it’s precisely the issue of being above the atmosphere… that might not seem like such an improvement to those of us who have been starwatching from underneath it all our lives, but refraction and distortion can make it absolutely impossible to measure small angles with precision and accuracy.
Something in earth orbit can still use the diameter of the earth’s orbit around the sun as a parallax baseline. And I wouldn’t be surprised if getting above the atmospheres would allow for measuring angles 3%-10% of the size of the smallest angles that can be measured from the earth’s surface. That turns into a 25x or better increase in range.
WAG
Remember, the two important elements are baseline and angle. Earth’s orbit may not be much compared to interstellar distances, but if we can measure the tiny angles accurately, that effectively magnifies the effects of our own orbit many times.
Actually, there are surviving Greek versions of it. The thing is that these weren’t available in western Europe during the Middle Ages, so the Latin translations that circulated, like that from the 12th century by Gherardo of Cremona, were based on the Arabic translations.
But texts of it in Greek started turning up in the 16th century - possibly ones that had come from Constantinople after 1453 - and there was a translation into Latin from one of those printed in 1528. An edition of 1538 in Greek was then the major one in use through the next century. The modern editions are primarily based on the Greek texts.
I’ve actually seen proposals (though rather pie-in-the-sky ones) for a network of radio interferometers scattered through the Solar System, which would have sufficient angular resolution to actually get trignometric parallaxes for quasars. Between that and their easily-measured redshifts, we could get a very precise and very reliable figure for the Hubble constant and other interesting cosmological parameters. It’ll probably never happen, as there are probably easier ways of getting the same quality of data, but it’s certainly possible.
