Today we are going to talk about the constellations that are seasonally visible in the Winter and Spring. From the Northern Hemisphere and astronomers in the Pacific Northwest, there are 30 visible constellations; five can be seen all year, while the others appear seasonally. Named after characters in Greek mythology, each constellation contains star patterns that abstractly resemble its namesake. As there are 5 circumpolar constellations, this article will be reviewing 13 of the 25 seasonally available constellations visible from the Pacific Northwest. We will review the remaining 12 seasonal constellations in a later article.
- Canis Major
In the second century, Canis Major was included in Ptolemy’s 48 constellations, and is counted among the 88 modern constellations. Its name is Latin for “greater dog” in contrast to Canis Minor, the “lesser dog”; both figures are commonly represented as following the constellation of Orion the hunter through the sky. The Milky Way passes through Canis Major and several open clusters lie within its borders. Sirius is the brightest star in the night sky at apparent magnitude −1.46 and one of the closest stars to Earth at a distance of 8.6 light-years. The only Messier object is M41 (NGC 2287), an open cluster with a combined visual magnitude of 4.5, around 2300 light-years from Earth. Located around 30′ northeast of NGC 2360, NGC 2359 (Thor’s Helmet or the Duck Nebula) is a relatively bright emission nebula in Canis Major, with an approximate magnitude of 10, which is 10,000 light-years from Earth can be a popular astrophotography target.
Cetus was a sea monster in Greek mythology as both Perseus and Heracles needed to slay, sometimes in English called ‘the whale’. The constellation Cetus is in the region of the sky that contains other water-related constellations: Aquarius, Pisces and Eridanus. Cetus lies far from the galactic plane, so that many distant galaxies are visible, unobscured by dust from the Milky Way. Of these, the brightest is Messier 77, a 9th magnitude spiral galaxy near Delta Ceti. It appears face-on and has a clearly visible nucleus of magnitude 10. Another object in Cetus is NGC 246, also called the Cetus Ring, which is a planetary nebula with a magnitude of 8.0. Among some amateur astronomers, NGC 246 has garnered the nickname “Pac-Man Nebula” because of the arrangement of its central stars and the surrounding star field.
Eridanus is a constellation in the southern celestial hemisphere, which is represented as a river. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is the sixth largest of the modern constellations. There are a bunch of NGC items such as NGC 1535, which is a small blue-gray planetary nebula visible in small amateur telescopes.
Gemini was one of the 48 constellations described by the 2nd century AD astronomer Ptolemy, and it remains one of the 88 modern constellations today. Its name is Latin for “twins,” and it is associated with the twins Castor and Pollux in Greek mythology. The constellation contains 85 stars of naked eye visibility.Since the sky area of Gemini is directed away from the Milky Way, there are comparatively few deep-sky objects of note. Famous members include M35, the The Eskimo Nebula or Clown Face Nebula, and The Medusa Nebula. The Geminids Meteor Shower does originate from this constellation.
The constellation is named after Orion, a hunter in Greek mythology. Betelgeuse, also designated Alpha Orionis, is a massive M-type red supergiant star nearing the end of its life. It is the second brightest star in Orion, and is a semiregular variable star. Rigel, also known as Beta Orionis, is a B-type blue supergiant that is the sixth brightest star in the night sky. Bellatrix is designated Gamma Orionis by Johann Bayer. It is the twenty-seventh brightest star in the night sky. The Orionids Meteor shower originates from this constellation, which sees its parent body being Halley’s Comet. Orions Belt has many stars including the Trrapezium and the Orion Nebula M42. Another Messier object in the area is Messier 78.
Named after the Greek mythological hero Perseus, this cluster is one of the 48 ancient constellations listed by the 2nd-century astronomer Ptolemy, and among the 88 modern constellations defined by the International Astronomical Union. It is surrounded by Andromeda, Cassiopea, Ca elopardalis, and Traingullum. The Perseids are a prominent annual meteor shower that appear to radiate from Perseus from mid-July, peaking in activity between 9 and 14 August each year. Famous members include two open clusters (NGC 869 and NGC 884) known as the Double Cluster, M34, M76 the Little Dumbell Nebula, and NGC 1499, also known as the California Nebula.
Taurus is one of the constellations of the zodiac and is located in the Northern celestial hemisphere, moreover, the constellation is a large and prominent constellation in the northern hemisphere’s winter sky. Its name derives from the Arabic for “the follower”, which is probably from the fact that the constellation follows the Pleiades during the nightly motion of the celestial sphere across the sky. It is one of the oldest constellations, dating back to at least the Early Bronze Age when it marked the location of the Sun during the spring equinox. During November, the Taurid meteor shower appears to radiate from the general direction of this constellation. In the northeastern quadrant of the Taurus constellation lie the Pleiades (M45), one of the best known open clusters, easily visible to the naked eye. The brightest member of this constellation is Aldebaran, an orange-hued, spectral class K5 III giant star. A degree to the northwest of ζ Tauri is the Crab Nebula (M1), a supernova remnant.
One of the 48 constellations described by the 2nd-century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth-brightest star in the night sky, the orange giant Arcturus. Epsilon Bootis, or Izar, is a colourful multiple star popular with amateur astronomers. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye.
Cancer is one of the twelve constellations of the zodiac and contains two stars with known planets, including 55 Cancri, which has five: one super-earth and four gas giants, one of which is in the habitable zone and as such has expected temperatures similar to Earth. At the heart of this sector of our celestial sphere is Praesepe, Messier 44, which one of the closest open clusters to Earth and a popular target for amateur astronomers. Cancer is the second dimmest of the zodiacal constellations, having only two stars above the fourth magnitude. Messier 67 also resides in this constellation.
Crater is one of the 48 constellations listed by the second-century astronomer Ptolemy. The constellation depicts a cup in the sky that has been associated with the god Apollo and is perched on the back of Hydra the water snake. There is no star brighter than third magnitude in the constellation.
Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees, and also the longest at over 100 degrees. It was spotted and included by Ptolemy in hiss 48 constellations. Hydra contains three Messier objects. M83, also known as the Southern Pinwheel Galaxy, M68, and M48. M83 is located on the border of Hydra and Centaurus, M68 is a globular cluster near M83, and M48 is an open star cluster in the western end of the serpent.
Leo is one of the constellations of the zodiac, lying between Cancer the crab to the west and Virgo the maiden to the east. It ws described by Ptolemy. Leo contains many bright galaxies; Messier 65, Messier 66, Messier 95, Messier 96, Messier 105, and NGC 3628 are the most famous, the first two being part of the Leo Triplet. The galaxy is also the originator of the Leonids. Leo contains many bright stars, many of which were individually identified by the ancients. There are four stars of first or second magnitude, which render this constellation especially prominent including Regulus.
Virgo is one of the constellations of the zodiac. Its name is Latin for virgin, lying between Leo to the west and Libra to the east. Virgo is the second-largest constellation in the sky, after Hydra. and the largest constellation in the zodiac. It can be easily found through its brightest star, Spica. There is a high amount of galaxies such as Messier 49, Messier 58, Messier 59, Messier 60, Messier 61, Messier 84, Messier 86, Messier 87, Messier 89, and Messier 90. M104, the Sombrero Galaxy is located about 10° due west of Spica
If you’re curious about what the technical definition of a constellation is, check out this article on the subject. If you’re curious about which circumpolar constellations are always visible from the Pacific Northwest, check out this wonderful article.