Alpha Andromeda

NS206

STAR OBSERVING PROJECT

ALPHA ANDROMEDA

Fall 2006-2007

Project Outline:

A. General Information About Alpha Andromeda

B. Mythological Story of Alpha Andromeda

C. Where is Alpha Andromeda on the Sky?

D. Observations of Alpha Andromeda

E. Reference List

A. About Alpha Andromeda:

Alpha Andromeda is the brightest star in Andromeda Constellation. Alpha Andromeda, also called Alpheratz, is the northeastern star of the Great Square of Pegasus. Almach, Gamma Andromeda is toward lower left, while Mirach (Beta Andromeda.) takes place below the center of constellation. The star near the lower edge at left of the system is in Triangulum. The M31, Andromeda Nebula, is located toward top center. Nu Andromeda (named as Nu And in the figure given below) is just down and to the left of it. Epsilon is the lower right of the trio down and to the left of Alpha Andromeda.

The figure given below shows the Andromeda Constellation:

B. Mythological Story of Alpha Andromeda:

The constellation of Andromeda is a heroine in a Grand Greek myth of the ancient Ethiopian dynasty. An etymological meaning given for the name: andro ÐŽomanÐŽ± + medea, a form of the Greek word medesthai which means ÐŽothinkingÐŽ±.

In Greek myth, Andromeda is the daughter of King Cepheus and Queen Cassiopeia of Ethiopia. She was chained to a rock in exposure to the sea monster called Cetus as a punishment for CassiopeiaЎЇs boast of beauty superior to that of the Nereids (the 50 daughters of the Old Man of the Sea, Nereus and Doris and granddaughters of Oceanus). Because of the jealousy, Nereids wanted Poseidon to avenge this insult who sent Cetus to lay waste to the country. But an oracle predicted that Ethiopia could be freed from this harassment if Andromeda were to be abandoned as a victim. The people in the country forced king to agree to this prediction and make Andromeda bounded to a rock. But Perseus the hero, who was returning from an expedition saw Andromeda and fell in love. He promised king to let her free if she could become his wife. And King Cepheus agreed and with the aid of his miraculous weapons, the hero Perseus killed Cetus and married Andromeda.

The asterism consists of several bright stars with magnitudes of about 2, and there is a splendid galaxy of M31, The Andromeda Galaxy, at the side of Princess Andromeda. It could be said that the galaxy makes the name of this constellation popular.

The Constellation chart for Andromeda is given below:

C. Where is Alpha Andromeda on the Sky?

Alpha Andromeda is located 97 light years from the Earth. Alpha Andromeda is composed of two close orbiting stars, which can be distinguished by very sensitive spectroscopic analysis. The larger one is ten times greater than the smaller and they orbit each other with a 96.7 days period. They are 200 times brighter than the Sun, which has a surface temperature of 13000 Kelvin.

Here is some tables containing special information about Alpha Andromeda

Observation data

Constellation Andromeda

Right ascension 00h 08m 23.3s

Declination +29Ўг 05ÐŽÐ' 26Ўе

Apparent magnitude (v) 2.07

Characteristics

Spectral type B8 IVp MnHg

B_V color index -0.11

U_B color index -0.46

Variable type ¦Ð'2 CVn

Astrometry

Radial velocity (Rv) -12 km/s

Proper motion (¦Ðœ) RA: