Questions tagged [history]

Questions regarding the history of astronomy, including discoveries and scientists.

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75
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2answers
14k views

Could the dinosaurs have seen the asteroid that killed them?

Wikipedia says the Chicxulub impactor is thought to have been a 10-15 km diameter object. Would it have been visible to a (human*) naked eye before impact? And if so, would it have appeared like a ...
6
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2answers
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Did Cassini return a photo of Saturn's rings shown from closer to Saturn?

A quote from a book, Perelandra by C.S. Lewis: "no eye looked up from beneath on the Ring of Lurga"; now Lurga is Saturn, and no human eye has been to Saturn, let alone at a lower altitude ...
5
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3answers
181 views

How did Astronomers mostly(?) agree to publish arXiv preprints along with peer-reviewed Journals? Was there pushback?

This excellent, thorough and well-sourced answer to Has a gravitational microlensing event ever been predicted? If so, has it been observed? includes four links to papers on adsabs.harvard.edu pages, ...
7
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Explanation of an imaginary transformation occurring in the determination of trigonometric series for the elliptical equation of the center

One of the oldest problems in astronomy, which dates back to to the time of Kepler, is the problem of development in infinite trigonometric series of the "equation of the center" - to ...
4
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1answer
616 views

What is the mnemonic reason behind b being galactic latitude? (in the Galactic Coordinates frame)

I'm not sure if this is a question that has been posted before, and I'm also not sure if the answer is really mnemonic. If that's the case, I'd like to understand why we assigned $b$ to latitude ...
6
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3answers
4k views

How did the authors of Surya Siddhanta find the diameters of other planets in the solar system?

The Surya Siddhanta, "a Sanskrit treatise in Indian astronomy from the late 4th-century or early 5th-century CE" is truly a great work. But how was it possible for the writers to find the exact ...
5
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1answer
154 views

Who discovered Wolf 359?

I always assumed that Wolf 359's discoverer had been Max Wolf, but I just found out that he simply measured its high proper movement and included it in his star catalog. Since Wolf 359 is a very ...
5
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2answers
999 views

Was Newton the first to mention the orbital barycenter?

A barycenter is the common center of mass of an orbiting system. Here is a illustrative gif from wikipedia: The first mention of something like a barycenter that I could find is in a translation of ...
4
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0answers
58 views

Equivalence of minor epicycle and eccentric

In epicycle-deferent astronomy, adding a second ”minor” epicycle to account for observational discrepancies is observationally equivalent to shifting the deferent into a so-called eccentric, or a ...
1
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1answer
75 views

On Augustus' Actual Prescription to Restore the Julian Calendar to Accuracy

I hope that I may ask this question here as I have seen some favorably received questions related to the Julian calendar on this site. From James Evans' book, ``The History and Practice of Ancient ...
3
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4answers
204 views

Nicolas Copernicus discovery

As I was reading about the heliocentric model, a question came up: How was Nicolaus Copernicus able to figure out that the sun is at the center of the solar system, and that all planets orbit around ...
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0answers
40 views

Statistics of the purposes of archeoastronomical sites?

Archeoastronomy is not the most prominent tag used here at astronomy SE. It can be defined as the interdisciplinary or multidisciplinary study of how people in the past "have understood the ...
15
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8answers
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Has great eyesight been necessary for astronomers?

In a different (but somewhat related) field, some baseball stars have been known to have "baseball eyes." That is, an exceptional ability to visually follow the trajectory of a 90+ mph baseball to a ...
3
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1answer
64 views

Historical estimates of the density parameter

From the reference in this answer I learned that our current estimate for the density parameter (i.e., the density of the universe divided by the critical density, which determines the shape of the ...
1
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1answer
114 views

Since when do astronomers have the notion that space is void? [duplicate]

Since when do astronomers have conjectured that space is void, and not full of air like our immediate environment? I am more interested about how long the notion has been around and how influential ...
8
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1answer
93 views

Mercury's spin-orbit resonance

When was it confirmed that Mercury has a 3:2 spin-orbit resonance and by whom (research group/radio observations...)? The first suggestion was made by Giuseppe Colombo in 1965. Its proximity to the ...
5
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1answer
64 views

Ptolemy’s understanding of the planet’s whereabouts

I imagine that Ptolemy’s epicycles were performed as real circles - around equants - in two dimensions, e.g that he was able not only to give the angles to planets and the Sun as seen from the Earth, ...
3
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1answer
90 views

What happened to the 2017 proposal on redefining planethood? Is this information available?

In 2017, Alan Stern et al. submitted a geophysical planet definition to the IAU for review which states “A planet is a sub-stellar mass body that has never undergone nuclear fusion and that has ...
0
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1answer
63 views

Researching mechanics without “fixed stars”

In the history of humanity, easily observable extra-(Solar System) objects greatly helped understanding certain phenomena inside the Solar System. Importantly, the “precession of the equinox”, and ...
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2answers
100 views

Why do astrologers use the “wrong” sign?

I realize this may be the wrong site for this question... I apologize if you consider it inappropriate but hope this community knows the answer. We just experienced the spectacular conjunction of ...
4
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2answers
168 views

Mystery CCD camera

What I know: this is a Meade-brand CCD camera. I believe it to be relatively old (2004?). It does not have a model number, and the only pictures I can find on the internet call it a "USB PC-...
10
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5answers
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Where to obtain Tycho Brahe's data?

I would like to obtain Tycho Brahe's data on Mars. What would be an authoritative source? One source I could find is this page (the data is given as an Excel file) but I have no idea can that be ...
6
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1answer
139 views

When was it first determined that the Sun is a star?

Just looking at the sky, it is not at all obvious that the Sun is a star: stars are fixed on the celestial sphere, they are point-like and not very bright, whereas the sun is a big (compared to a star)...
2
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1answer
165 views

Why have brown dwarf classes been dubbed L, T and Y?

The classes used to categorize stars (O, B, A, F, G, K, M) are in a bizarre order for historical reasons. Stars were labeled based on the spectral lines that were visible, then the categories were put ...
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2answers
95 views

What was the definition of a planet before August 24, 2006?

In 2006, the IAU produced a definition of what it is to be a planet. This definition famously excludes Pluto, to the disarray of this small body's fans. Before this decision, what was the definition ...
2
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1answer
77 views

What other definitions for a planet were proposed?

This article from the IAU states The first draft proposal for the definition of a planet was debated vigorously by astronomers at the 2006 IAU General Assembly in Prague and a new version slowly took ...
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0answers
47 views

Angles in Ptolemaic Model

I am about to work with Ptolemy's Model for the motion of an upper Planet (Mars). I use a epicycle rolling on the deferent. As a first step, I am just interested in the shape of the trajectory, which ...
20
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1answer
579 views

What are Kepler's laws (as he wrote them)?

There are of course many, many sources that quote Kepler's laws of planetary motion. This is preventing me from finding out what I really want to know: which is - what are Kepler's laws as he wrote ...
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2answers
99 views

When was the distance to a star measured for the first time without using parallax?

This is somewhat of a follow-up to When was the parallax of a star first measured? Once the distance to the nearest stars was determined, it was possible to discover physical properties of stars (such ...
1
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1answer
69 views

How were the distances to stars measure before parallax?

A comment under When was the distance to a star measured for the first time without using parallax? mentions that the distance to stars was measured before parallax was possible. How was this done?
3
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1answer
95 views

What comet's tail did Earth pass through before Halley's?

This answer to Any record of the Earth passing through the tail (not trail) of a comet? mentions Earth passed through the tail of Halley's Comet in 1910. It caused a bit of a panic due to claims that ...
3
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0answers
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What were they expecting to see when Halley's comet appeared in 1910?

This answer to Any record of the Earth passing through the tail (not trail) of a comet? mentions Earth passed through the tail of Halley's Comet in 1910. It caused a bit of a panic due to claims that ...
4
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1answer
96 views

Any record of the Earth passing through the tail (not trail) of a comet?

Discussion below the Space SE question How hard is it to fly through the tail of a comet? Has it been done? has led me to ask if there is any record of the Earth passing through the tail of a comet. ...
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1answer
181 views

What exactly is a Hamiltonian telescope? Is this one?

This comment on the current answer to Why is this telescope so short? How hard is it to make such a fast primary? says In this forum topic Borisov appears to call it an f/1.5 Hamiltonian. Wikipedia'...
4
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1answer
391 views

Sorting out Julian Day, Julian Date, Julian Day number, Julian Day Calendar, and Julian Day Table

In this answer I mention day number which is 1 on the first day of each calendar year (January 1) and increments to 365 or 366 on December 31 of that year. There was an edit proposed, which included ...
10
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4answers
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How much does the sky change in a few thousand years?

The "fixed stars" are not actually fixed, the earth's tilt changes over time etc., but all that happens slowly on human timescales. Imagine a Babylonian astronomer (or astrologist?) ...
0
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2answers
134 views

Did the night sky ever change in recorded history?

I wonder whether there has ever been a major change of the firmament in recorded history, like changes in the positions of stars, changes in constellations, or stars disappearing after going supernova....
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2answers
67 views

Why does the Simbad page “A.A. Michelson's Jovian Galilean-satellite interferometer” show data for Betelgeuse?

When searching for things related to How did Michelson measure the diameters of jupiter's moons using optical interferometry? I came across the ui.adsabs.harvard.edu entry A. A. Michelson's Jovian ...
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1answer
111 views

When was the parallax of a star first measured?

Telescopes like Gaia measure the parallax of stars with a great precision. But for stars that are beyond 11 kpc, their parallax is still too small to be measured. With Earth-bound telescopes, only the ...
3
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0answers
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How did Michelson measure the diameters of jupiter's moons using optical interferometry?

In Betelgeuse: How its Diameter was measured (Chant, C. A., Journal of the Royal Astronomical Society of Canada, Vol. 15, p.133, Bibliographic Code: 1921JRASC..15..133C) the author says: The paper in ...
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2answers
70 views

Before the 1761 transit, what was our best estimate of the distance to the Sun?

In 1761, many expeditions were launched to determine the distance to the Sun using parallax during the transit of Venus. Prior to the 1761 transit, what was the best estimate for the Earth-Sun ...
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34 views

Records of Venus transits prior to 1761

Following the publication in 1716 of Edmond Halley's method to determine the solar parallax with the transit of Venus, many expeditions were launched to observe the 1761 transits. The following ...
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0answers
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When was the variation of apparent diameter of the moon first measured?

The orbit of the Moon around the Earth isn't quite a circle. Since distance between the Earth and the Moon changes over time, the apparent diameter of the Moon also varies very slightly. With a ...
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2answers
4k views

How was the mass of Venus determined?

The mass of Venus seems rather complicated to determine to me: Venus doesn't have any satellites, so you can't just apply Kepler's third law (like you would with Jupiter or Saturn for instance) to ...
5
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1answer
448 views

Why were the Magellanic Clouds named that way?

From the Wikipedia article, the Large and Small Magellanic Clouds were observed prior to Magellan's expedition, and the name only stuck long after Magellan's expedition (at first, they were called ...
3
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2answers
157 views

What was the field of view of the Ohio State University Radio Observatory of Wow! signal fame?

This answer to Did comets 266P/Christensen or P/2008 Y2 (Gibbs) cause the Wow! signal? points out that the comets in question were nowhere near where the radio telescope was pointed. Wikipedia says ...
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1answer
75 views

When was the diameter of Titan first measured?

Titan is enshrouded in a thick opaque cloud of methane : with a telescope, you can't see the moon's surface. Because of this, from a distance, you can only see the diameter of the moon + its ...
28
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2answers
7k views

How did Eratosthenes know that the sun is far away?

The famous measurements and calculations done by Eratosthenes around 300 BC are very widely known. He concluded correctly that the circumference of the Earth is about $252\,000$ times the length of an ...
0
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1answer
27 views

Who coined the phrase “martian dichotomy”?

This question is adjacent to this other one. The martian dichotomy refers to the fact that the northern and southern hemisphere are radically different on Mars, with different surface ages and ...
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1answer
134 views

Why are Uranus' satellites named after characters in Shakespeare?

Oberon, Titania, Ophelia, Puck, Miranda... Uranus' satellites are named for characters in the works of Shakespeare and Pope. Yet the names of Jupiter and Saturn's moon come from the Roman and Greek ...