Abbreviation:

Per

English name:

Perseus

Coordinates

see Stellar data

Particulars:

• Double star gamma Per, epsilon Per, zeta Per, eta Per, tau Per
• Occulting variable star beta Per (period: 2,87 days)
• Semiregular variable star rho Per
• Open star clusters M34, NGC 884, NGC 869, NGC 1342, NGC 1444, NGC 1528
• Planetary nebula M 76
• Diffuse nebula NGC 1499
• Galaxies NGC 1003, NGC 1023
• Meteor Showers: Perseids, Zeta Perseids

General:

One of the larger constellations of the northern hemisphere. The northern border reaches as high as DECL=+59 degrees, the southern border reaches DECL=+31 degrees (touching Aries and Taurus). From east to west this constellation extends from roughly RA=4h 50m to RA=1h 30m.
Perseus gives name to one of the constellation families.
The figure of Perseus ist thought to held the head of Medusa in his hand (the star beta Per represents the evil eye of her).

Stars and other objects

The leading star alpha Per, called Marfak or Algenib, is an F5 supergiant with 1.79 mag, which makes it, together with alpha UMa, the 32nd brightest star in the sky. It lies within a widely scattered cluster of stars making it an interesting region for binoculars.
Small telescopes may have a problem in resolving the 8th mag companion (an A2 main sequence star) of the B0.5 main sequence star epsilon Per. The brighter component is of 2.89 mag and therefore the fainter component may just be lost in the intense glow of the first one.
Another pair with a large brightness contrast is zeta Per, a B1 supergiant of 2.85 mag and its 9th mag companion.
An attractive pair for small telescopes is eta Per: a red and a blue star of 4th and 9th mag sitting in a star rich field.
The eclipsing binary beta Per, called Algol is one of the most famous variable stars in the sky. The two stars revolve each other every 2 days and 21 hours. During the eclipsing phase the brightness varies from 2.2 mag to 3.5 mag.
The brightness of the variable star rho Per varies semiregularily from 3rd mag to 4th mag. This changings are happening nearly monthly.
An easy object for small telescopes is M34. This cluster is bright and quite large. In a dark night it can be seen with the naked eye. Individual stars can be resolved even with small optical power.
The two open star cluster NGC 869 and NGC 884, commonly named h Per and chi Per, are the famous Double Cluster of Perseus (located at the northern edge). These two related star clusters belong to the best targets for small instruments. Viewed in a clear dark night the clusters appear to the naked eye as one hazy patch in the sky. Using little optical help stars scattered over 0.5 degrees of the sky are revealed. With small scopes some of the red stars can be seen in NGC 884. It is less bright and less rich cluster of the pair. The distance to that pair is estimated to be about 7000 lightyears.
To observe NGC 1528 most effectively one should use low telescopic power.
The planetary nebula M 76, called Little Dumbbell Nebula, is a quite faint object, but with some nice irregular extensions in its appearence. For more information please refer to the Messier database.
The Perseids are one of the most famous and most glorious meteor showers. It duration extends from July 23th to August 22nd. The maximum occurs on August 12th/13th, but it is also worth to observe this shower before and after this date. The Perseids meteors are known to be bright; sometimes the explode and leave trains.
The existence of the meteor shower Zeta Perseids has been discovered 1947. It is one of the daylight showers. The meteors fall between May 20th and July 5th; the maximum occurs on June 13th. See Gary Kronk's database about meteors showers for detailed information.

Mythological Background: