Constellations

The Zodiac Constellations

The Sun, Moon and planets all travel a narrow band of sky centered on the ecliptic, the plane of Earth's orbit. Thirteen IAU constellations cross that line: the 12 of the ancient zodiac and Ophiuchus, which the Sun passes through every December.

Swipe sideways to pan the band.

The sky 20° either side of the ecliptic (gold dashes), east to the left. Gold dots mark the Sun on the 1st and 15th of each month. Outlined: the 13 constellations the Sun passes through. Click a name to open its chart.
On the ecliptic
1312 signs plus Ophiuchus
Longest Sun stay
Virgo44 days
Shortest Sun stay
Scorpius7 days
Precession
1° per 72 yearsone full turn in about 25,800 years

The Sun spends 44 days in Virgo and 7 in Scorpius

Astrology gives each sign an equal 30° of the ecliptic. The IAU boundaries, drawn in 1930, are unequal, so the Sun's stay in each constellation ranges from 7 days in Scorpius to 44 days in Virgo. A constellation is best seen about six months after the Sun passes through it, when it is opposite the Sun and up all night.

ConstellationSun's actual datesDaysAstrology sign datesTime in constellationBest monthMessier
CapricornusJan 21 - Feb 1627Dec 22 - Jan 19
September1
AquariusFeb 17 - Mar 1224Jan 20 - Feb 18
October3
PiscesMar 13 - Apr 1938Feb 19 - Mar 20
November1
AriesApr 20 - May 1425Mar 21 - Apr 19
December
TaurusMay 15 - Jun 2138Apr 20 - May 20
January2
GeminiJun 22 - Jul 2130May 21 - Jun 20
February1
CancerJul 22 - Aug 1121Jun 21 - Jul 22
March2
LeoAug 12 - Sep 1737Jul 23 - Aug 22
April5
VirgoSep 18 - Oct 3144Aug 23 - Sep 22
May11
LibraNov 1 - Nov 2323Sep 23 - Oct 22
June
ScorpiusNov 24 - Nov 307Oct 23 - Nov 21
July4
OphiuchusDec 1 - Dec 1818not a sign
July7
SagittariusDec 19 - Jan 2033Nov 22 - Dec 21
August15

Computed for 2026 from the Sun's position and the IAU boundaries; dates shift by a day from year to year.

Precession has moved the Sun's dates about a month later than the signs

Earth's axis wobbles like a spinning top, tracing a circle once every 25,800 years. The wobble, called precession, slides the March equinox west along the ecliptic by about 1° every 72 years. Astrology's signs are measured from the March equinox and move with it; the constellations stay with the stars. When the signs were set about 2,000 years ago, the equinox lay in Aries. It has since moved about 28° west and now lies in Pisces, so the Sun reaches each constellation roughly a month after the date of its sign. Around 2600 the equinox will cross into Aquarius.

Ophiuchus is the 13th constellation on the ecliptic

The Sun crosses the southern foot of Ophiuchus, the Serpent Bearer, from Dec 1 to Dec 18, longer than it spends in neighboring Scorpius. Ophiuchus was never one of the 12 signs: Babylonian astronomers divided the zodiac into 12 equal parts to match the 12 months, and Greek astronomers kept the scheme. The ecliptic has crossed Ophiuchus all along; the IAU boundaries of 1930 only made it official.

The Moon and planets stray into constellations outside the zodiac

The Moon's orbit tilts 5° to the ecliptic and the planets' orbits by up to 7° for Mercury, so they wander a few degrees either side of the Sun's path. That carries them into Cetus, Orion, Sextans, Corvus, Auriga and Pegasus, among others. Pluto, with an orbit tilted 17°, has passed through many more.

Video: the zodiac constellations

The Zodiac Zone: 12 Constellations of The Ancients · Watch on YouTube