Pisces, a zodiac constellation, holds a place in both astronomy and ancient traditions. Its name, derived from Latin, translates to “the fishes,” and its symbol depicts two interconnected fish. The question of how many stars reside within this celestial grouping is more intricate than a simple numerical answer, depending on how one defines and observes them in the night sky.
Counting the Stars of Pisces
The number of stars one can observe within the Pisces constellation varies considerably based on viewing conditions and equipment. While some sources indicate around 18 main stars forming the traditional pattern, others suggest that up to 86 stars within Pisces are visible to the naked eye under optimal dark sky conditions. The visibility threshold for the human eye is typically around magnitude 6.0 to 6.5, meaning stars fainter than this are not seen without assistance. Pisces is one of the dimmer zodiac constellations, with no stars brighter than magnitude 3.0 and only two brighter than magnitude 4.0.
The International Astronomical Union (IAU) officially divides the celestial sphere into 88 constellations, each with precise boundaries. These boundaries define specific regions of the sky, meaning any star or celestial object located within Pisces’ designated area is considered part of the constellation. When observed with telescopes, the number of stars within these boundaries expands dramatically into thousands or millions, far exceeding what is visible to the naked eye. Pisces is a large constellation, ranking as the 14th largest in the sky, encompassing an area of 889 square degrees.
Locating Pisces in the Sky
Pisces is best viewed during the autumn and early winter months in the Northern Hemisphere, particularly in November when it reaches its highest point in the evening sky. It is situated in the northern celestial hemisphere, nestled between several other prominent constellations.
Its celestial neighbors include Aquarius to the southwest and Aries to the east. The constellation is also located near Pegasus, Andromeda, Triangulum, and Cetus. A practical way to locate Pisces is by first identifying the Great Square of Pegasus, as Pisces lies to its south and west.
The constellation’s characteristic shape is often described as a “V” or resembling two fish connected by a cord. One of the fish is marked by a group of stars known as the “Circlet,” found south of the Great Square of Pegasus. This pattern helps observers trace the celestial fishes.
Notable Stars Within the Constellation
While Pisces is not known for exceptionally bright stars, it contains several notable ones. Alrescha, also designated Alpha Piscium, is a significant star marking the knot in the cord that traditionally connects the two fish. This binary star system has an apparent magnitude of around 3.62 to 4.33, making it visible to the naked eye under suitable conditions. Its two components are A-class stars, appearing off-white and bluish.
Another star is Fumalsamakah, or Beta Piscium, meaning “mouth of the fish.” This blue-white star has an apparent magnitude of about 4.40 to 4.53 and is a variable main-sequence star. Fumalsamakah is also characterized as a shell star, a rapidly rotating body with a disk of matter at its equator.
Pisces also hosts Van Maanen’s Star, a less conspicuous but scientifically significant object. This white dwarf is a dense remnant of a star that has exhausted its nuclear fuel. With an apparent magnitude of 14.22, it is too dim to be seen without a telescope. Despite its faintness, Van Maanen’s Star is the closest known solitary white dwarf to our Sun, possessing about 68% of the Sun’s mass but only 1% of its radius.