# Tag Info

7

As you said, the Sun takes a year to cycle the Zodiac, and it takes a year between two spring or autumn equinoxes. Both statements are true, but "year" in them means two different things. It takes a sidereal year to cycle the Zodiac, but it takes a tropic year to cycle between equinoxes. Since the tropic year is about 20 minutes shorter, the equinoctial ...

7

Running a simulation in Stellarium, on March 21st, you can just about see Pisces at about 7pm, but it is setting, and at 5am Aquarius is just rising, before being hidden by the sun. The sun is "in Pisces" on the 21st (the astrological houses have not been updated) but it is a pretty big constellation! This means that you can see, or partly see all the ...

6

In some cases, constellations don’t look like their names because they were completely mistranslated by Greek astronomers from Mesopotamian constellations. One of these is Pegasus, the Flying Horse. Originally, it was 𒀸𒃷 AŠ.IKU, One Field (piece of land, but also measurement unit), to the Mesopotamians. However, IKU sounds like Mycenaean 𐀂𐀦 i-qo, “horse,”...

6

Who says they don't? Surely it just depends on how you play "join the dots"? The human brain will make out patterns where it wishes and what things look like is largely in the eye of the beholder. The second explanation isn't true. Although the relative positions of the stars do change, they have not changed very significantly over a period of 3000 ...

5

TL;DR: Calculating the right ascension (i.e. converting from ecliptic to equatorial coordinates) requires some spherical trigonometry, but fortunately there are internet tools that will do this, such as here. The resulting RA coordinates are: Aries 0h 0m 0s; Taurus 1h 51m 39s; Gemini 3h 51m 16s; Cancer 6h 0m 0s; Leo 8h 8m 44s; Virgo 10h 8m 21s; Libra 12h 0m ...

4

I don't really know what you mean by "Zodiac stars". I suppose you mean the stars of the 12 traditional Zodiac constellations. Alpha Scorpii, known as Antares, or Jyeshtha in Hindu astrology, is a red supergiant. It is in a similar stage of its lifecycle to Betelgeuse. It is expected to explode in a supernova in the next 10000-100000 years (the ...

4

Depends on you considered as "see an astrological sign", because the constellations are pretty big and are not always on top of the elliptic or in their 30º spot of it. Scorpius for example is a bit off the ecliptic, so a general calculation on the visibility of the ecliptic might tell you that you see the right longitude (210º), but (most of) Scorpio could ...

4

This is far too complicated. You can find any asterism in the sky far more simply by remembering its shape and its position relative to other (perhaps brighter) constellations. For the Zodiac constellations, they are all in a band that (in the Northern hemisphere) goes from East through South, to West. In the winter, that band will be high is the sky. In ...

4

The Zodiac sign of a month is decided by the month when the Sun is "in" that sign from the point of view of Earth. (See Mike G's comment below - because of the precession of the Earth, Zodiac signs are now 30 degrees "off" from their original markings/associations with the months of the year.) I believe that August is actually the month ...

3

Guy Ottewell makes a comprehensive Astronomical Calendar each year. From the 2020 edition: 8959.117 Apr 19 SUN 15 Sun enters the astrological sign Taurus, i.e. its longitude is 30° That's 2020-04-19 ~15h UT, which falls on April 20 in far eastern terrestrial longitudes and April 19 everywhere else. The next such event is 1 ...

3

I think the reverse question can be asked with the same reasoning: how does it come the zodiac constellations actually show fish, cancer etc. At least they didn't change significantly in historic times - the fixed stars move much too slowly for that. The answer is quite simple: be creative, use your imagination. They are the ancient comic style of stick ...

2

I assume that by "zodiac stars or the stars of lunar mansions" you're referring to visible stars that are within 8° or so of the ecliptic, since that's the ecliptic latitude range where the Sun, Moon, and planets appear. Wikipedia has an article listing the known Milky Way supernova candidates. Some of those are currently visible stars in zodiac ...

2

One point not made clearly above. With unpolluted dark skies many more stars were routinely visible. Today we are often looking at just the brightest handful of 20 or 30 stars that make up a figure.

2

The equinoxes are where the ecliptic crosses the equator. As the Earth's axis and equatorial plane pivot under precession, the equinox points migrate westward along the ecliptic, 360° in 25800 years or 1.4° per century. This animation shows the vernal equinox drifting 28° in 20 centuries of precession: Images generated by Stellarium The Sun ...

2

The stars are not visible during the day, but they are still there (we just can't see them because of the brightness of the sun). We can't see the stars, but we can calculate where they would be if we could see them. Over the course of the year the sun appears to move relative to the stars. This is actually due to the orbit of the Earth around the sun. ...

2

A sidereal zodiac is not the same as the IAU constellations but corresponds more closely to them than the Western tropical zodiac does, e.g. the eastern edge of Virgo remains near Spica despite precession. I assumed equal 30° blocks of ecliptic longitude with the J285.25 equinox as origin (Lahiri ayanamsa). Your local tradition may differ slightly, but ...

2

The key coordinate is the Sun's geocentric ecliptic longitude: 0° at the March equinox, 90° at the June solstice, 180° at the September equinox, and 270° at the December solstice. The tropical zodiac subdivides each of these four 90° spans into three 30° blocks of ecliptic longitude. The Gregorian calendar is designed to keep the ...

2

The position of the sun, relative to the stars, at the time of the equinox changes slowly and predictably. This means that we know to a high degree of precision exactly where the sun was at the time of the equinox in 1500. It is pretty easy to calculate The position of the sun at the time of the equinox changes by about 1 degree every 71.3 years. The sun ...

1

What is the astronomical logic in it? Based largely on what Wikipedia says about the history of the zodiac it seems that the choice was made by Babylonian astronomers (and astronomy and astrology were heavily interwoven at that time) sometime during the rough period 1000 BC to 500 BC. Wikipedia quote : Around the end of the 5th century BC, Babylonian ...

1

You don't clarify whether you must see the whole constellation or perhaps seeing any star of the constellation suffices. Right now, 07 April 2020, 14:58:21 UTC, at $65^{\mathrm{o}} 38' 55.14'' \mathrm{S}$ $34^{\mathrm{o}} 3' 14.60'' \mathrm{E}$ at least one star from each zodiacal constellation except Aries is barely above the horizon (assuming an idealized ...

1

Zodiac signs are equal 30° divisions of the ecliptic. In the Western tropical zodiac, these are linked to the equinoxes and solstices, and named after the nearest constellations at the time Ptolemy wrote about them. The equinoxes precess westward 1.4° per century, so the signs currently lie 25° to 30° west of their namesake constellations. ...

1

Terminology is critical. As mentioned in other answers, precession causes the equinoxes (the points where the ecliptic intersects the celestial equator) to move from one constellation to another. For example, the March equinox was in the constellation Aries in the time of the ancient Greeks, is in the constellation Pisces today, and will be in the ...

1

As the question is pointing out, because of Earth's thick atmosphere we have quite a bright sky, and so we can not easily see stars during the day. So how can we talk about the position of the Sun with respect to the stars if the stars around the Sun can't be seen? Basic answer: By using star charts, and the very steady and well known rotation speed of the ...

Only top voted, non community-wiki answers of a minimum length are eligible