Pegasus (constellation)

Pegasus
Missing image Pegasus_constellation_map.png Pegasus click for larger image
Abbreviation	Peg
Genitive	Pegasi
Symbology	the Winged Horse / Pegasus
Right ascension	23 h
Declination	15°
Area	1121 sq. deg. Ranked 7th
Number of stars (magnitude < 3)	5
Brightest star	Enif (ε Peg) (App. magnitude 2.39)
Meteor showers	July Pegasids
Bordering constellations	Andromeda Lacerta Cygnus Vulpecula Delphinus Equuleus Aquarius Pisces
Visible at latitudes between +90° and −65° Best visible during the month of October

Pegasus is a northern constellation, named after the mythological Pegasus. It is one of the 88 modern constellations, and was also one of the 48 constellations listed by Ptolemy.

Contents

1 Notable features

2 Notable deep sky objects

3 History and mythology

4 Visualization

5 Stars

6 External links

Notable features

α Peg (Markab), β Peg, and γ Peg, together with Alpheratz (α Andromedae) form the large asterism known as the Square of Pegasus. A star in this constellation, 51 Pegasi, is orbited by the first true extrasolar planet (planets orbiting a star other than the Sun) to have been discovered.

Notable deep sky objects

M15 - a globular cluster near the head (ε Peg) of the Pegasus.
NGC 7742 - a Type 2 Seyfert galaxy in the constellation Pegasus.

History and mythology

Pegasus has an appearance resembling a grazing horse, with a large square area as its body [1]. Due to the presence of the 4 brightest stars in the square, i.e. the 4 horses of pegasus, this may be part of the origin of the myth of the Mares of Diomedes, one of The Twelve Labours of Herakles, together with another feature in the Zodiac sign of Aquarius, namely Aquarius itself, pouring out the waters.

The star Alpheratz, one of the 4 stars in Pegasus' square, was later considered to be part of Andromeda. By moving the star, the square became a triangle attached to a stick body, thus resembling a wing. As a winged horse, Pegasus features in Greek mythology as its namesake, Pegasus.

Visualization

Pegasus' brightest stars (of the second magnitude) are Alpha Pegasi and Beta Pegasi, which together with Gamma Pegasi (third magnitude) form the triangular wing of the horse.

The body of the horse consists of a quadrilateral formed by the stars Alpha Pegasi, Lambda Pegasi, Iota Pegasi, and Xi Pegasi.

The front legs of the winged horse have two stars of the fourth magnitude which have no Bayer designations but which do have Flamsteed numbers: 1 Pegasi and 9 Pegasi.

The stars Epsilon Pegasi and Theta Pegasi belong to the hind legs, with Epsilon Pegasi being of the third magnitude. Rho Pegasi and Sigma Pegasi belong to the tail, but they are both dim: of the fifth magnitude.

Eta Pegasi and Pi Pegasi form the head: Pi Pegasi is the snout, and Eta Pegasi has magnitude three. Mu Pegasi is the beginning of the neck.

Stars

Stars with proper names:

Markab [Marchab] or Menkib al Faras [Matn al Faras] (54/α Peg) 2.49
< مركب markab vehicle [saddle, boat, etc.]
< منكب الفرس minkab[u] al-faras [The] shoulder of the horse
< متن الفرس matn[u] al-faras [The] body of the horse

Scheat [Sheat, Seat Alpheras] (or Menkib, see ξ Per) (53/β Peg) 2.42
< ? as-sa'id al-faras The upper arm of the horse

Algenib (88/γ Peg) 2.83
< الجنب al-janb the flank
or < الجانبal-jānib the flank

δ Peg: moved to Andromeda as α And, see Alpheratz

Enif [Enf, Enir, Al Anf] or Fom [Fum al Faras] or Os Pegasi (8/ε Peg) 2.38
< الأنف al-�anf nose
< الفم الفرس al-fum al-faras The mouth of the horse
< ōs pēgasi The mouth of Pegasus, < πήγασος

Homam [Homan, Humam, Al Hammam] (42/ζ Peg) 3.41
< سعد الهمام sa^{c^{d[u] al-humām}} the high-minded [man]

Matar [Sad al Matar] (44/η Peg) 2.93
< سعد المطر sa^{c^{d[u] al-maţar}} Luck of the rain

Baham [Biham, Sad al Baham] (26/θ Peg) 3.53
< سعد البهايم sa^{c^{d[u] al-bahāyam}} Luck of the livestock

Sadalbari [Sad al Bari] or Sad al Nazi (48/μ Peg) 3.51
< سعد البري sa^{c^{d al-bariyy}} Luck of the guiltless one
< ? Luck of the starving camel?

Salm or Kerb [El Khereb] (or Markab, see α Peg (62/τ Peg) 4.58

Stars with Bayer designations:

24/ι Peg 3.77; 10/κ Peg 4.14; 47/λ Peg 3.97; 22/ν Peg 4.86; 46/ξ Peg 4.20; 43/ο Peg 4.80; 29/π Peg 4.28; 27/π¹ Peg 5.58; 50/ρ Peg 4.91; 49/σ Peg 5.16; 68/υ Peg 4.42; 89/χ Peg 4.79; 81/φ Peg 5.06; 84/ψ Peg 4.63

Stars with Flamsteed designations:

1 Peg 4.08; 2 Peg 4.52; 3 Peg 6.19; 4 Peg 5.66; 5 Peg 5.46; 7 Peg 5.30; 9 Peg 4.34; 11 Peg 5.63; 12 Peg 5.29; 13 Peg 5.34; 14 Peg 5.07; 15 Peg 5.52; 16 Peg 5.09; 17 Peg 5.54; 18 Peg 6.00; 19 Peg 5.65; 20 Peg 5.61; 21 Peg 5.83; 23 Peg 5.69; 25 Peg 5.79; 28 Peg 6.45; 30 Peg 5.37; 31 Peg 4.82; 32 Peg 4.78; 33 Peg 6.20; 34 Peg 5.76; 35 Peg 4.78; 36 Peg 5.60; 37 Peg 5.51; 38 Peg 5.64; 39 Peg 6.43; 40 Peg 5.84; 41 Peg 6.33; 45 Peg 6.27; 51 Peg 5.45 – has a planet; 52 Peg 5.76; 55 Peg 4.54; 56 Peg 4.76; 57 Peg 5.05; 58 Peg 5.39; 59 Peg 5.15; 60 Peg 6.19; 61 Peg 6.51; 63 Peg 5.58; 64 Peg 5.35; 65 Peg 6.28; 66 Peg 5.09; 67 Peg 5.56; 69 Peg 5.99; 70 Peg 4.54; 71 Peg 5.33; 72 Peg 4.97; 73 Peg 5.63; 74 Peg 6.26; 75 Peg 5.49; 76 Peg 6.30; 77 Peg 5.09; 78 Peg 4.93; 79 Peg 5.95; 80 Peg 5.77; 82 Peg 5.30; 85 Peg 5.80; 86 Peg 5.55; 87 Peg 5.57|

Other notable stars:

HD 209458 (V376 Peg) 7.65 – has a transiting planet

Constellations listed by Ptolemy

The 88 modern Constellations

External links

Missing image
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Commons

Wikimedia Commons has more media related to:

Pegasus

The Deep Photographic Guide to the Constellations: Pegasus