The core appears condensed and a bit asymmetric. NGC is a relatively bright face-on spiral galaxy, located 1. A mm instrument reveals a small concentrated core with a faint, star-like nucleus. Two additional galaxies occupy the field of view. The faintest by far is NGC Listed as 1. Much easier is NGC , which lies 5. This time the orientation presents us with an almost circular object, 1. Locate it via the southern edge of the Great Square.
A mag. A mm scope shows NGC as having a high surface brightness. Next, we head north to find the barred spiral galaxy NGC The brighter component in the system is a bright giant of the spectral type G2 II, four times more massive and times more luminous than the Sun. The companion is a main sequence star belonging to the spectral class F0 V.
Theta Pegasi belongs to the spectral class A2 Vp and is about 67 light years distant from Earth. It has a visual magnitude of 3. It is 25 times more luminous than the Sun and has 2. It has a radius almost ten times solar, but is only slightly more massive than the Sun, about 2. It belongs to the spectral class G5V and has an apparent magnitude of 5. It is also older than the Sun, with an estimated age between 6.
The exoplanet, 51 Pegasi b, was discovered on October 6, It has at least half the mass of Jupiter. The planet was nicknamed Bellerophon. IK Pegasi is a double star approximately light years distant. It has a visual magnitude of 6. The two stars in the system have an orbital period of The brighter component is a main sequence star of the spectral type A8m.
It is classified as a Delta Scuti variable and its variation cycle repeats itself The companion star, IK Pegasi B, is a white dwarf. It is the nearest supernova progenitor candidate known, and will eventually go out as a Type Ia supernova once the brighter star in the system evolves into a red giant and grows a radius that allows the white dwarf to accrete matter from its expanded gaseous envelope.
Messier 15 is a globular cluster, about 18 arc minutes in size. It has an apparent magnitude of 6. With an absolute magnitude of The brightest stars in the cluster are of magnitude Messier 15 is a globular cluster — a spherical conglomeration of old stars that formed together from the same cloud of gas, found in the outer reaches of the Milky Way in a region known as the halo and orbiting the Galactic Centre.
This globular lies about 35 light-years from the Earth, in the constellation of Pegasus The Flying Horse. Astronomers think that particularly dense globulars, like this one, underwent a process called core collapse, in which gravitational interactions between stars led to many members of the cluster migrating towards the centre. Messier 15 is also the first globular cluster known to harbour a planetary nebula, and it is still one of only four globulars known to do so.
The total exposure times were s and s respectively and the field of view is 3. M15 is believed to be 12 billion years old, which makes it one of the oldest globular clusters known. It contains more than , stars, among them a significant number of variables and pulsars, including the double neutron star M15 C. The cluster is also home to Pease 1, a planetary nebula discovered in Pease 1 was the first planetary nebula discovered within a globular cluster.
The nebula has an apparent magnitude of They lie about million light years from Earth. Four of the five galaxies were the first compact galaxy group ever discovered. The brightest galaxy in the group is NGC , which is only 40 million light years distant.
The other four galaxies in the group form a physical association, the Hickson Compact Group 92, and will eventually merge.
As the Square rises in prominence during autumn evenings, it becomes a handy guidepost to finding more constellations, including some of the dimmer members of the Zodiac: Aries, Pisces, Aquarius, and Capricornus.
Like the Summer Triangle, the Great Square of Pegasus is also huge, but Pegasus itself is even larger; Out of the 88 constellations, Pegasus is 7th in size, and it feels even larger as the stars in its neighboring constellations are much dimmer.
First discovered in , it contains the first galaxy group discovered which includes 4 of the 5 galaxies making up the Quintet — and has been studied extensively ever since. One day this group will merge into one supergalaxy! While famous, these galaxies are hard to spot in all but the largest backyard telescopes — but are a favorite target of astrophotographers.
Take a virtual flyby of these galaxies with a tour created from Hubble data at: bit. Bacon, J. Brown, an observational astronomer at Monash University in Australia, wrote that NGC is close to the Milky Way in shape , which makes the galaxy an interesting object when astronomers make comparisons with our own neighborhood.
The Einstein Cross, a quasar , is an excellent example of gravitational lensing — the process by which distant objects are magnified by the gravity of closer objects. The quasar is about 8 billion light-years from Earth and sits behind a galaxy that is million light-years away.
Four images of the quasar appear around the galaxy because the intense gravity of the galaxy bends the light coming from the quasar. The name comes from the winged white horse that was the sire of Poseidon in Greek mythology. The story of Pegasus begins with a battle between Perseus and Medusa.
One day, the warrior Bellerophon tried to ride Pegasus to Mount Olympus, enraging Zeus so much that he sent a gadfly to bite Pegasus.
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