Chapter 4 The Stargazer's Guide to the Night Sky

Why is it useful to know the constellations, asterisms, and bright stars?

1) It helps you to understand how you are oriented: what direction you are facing, etc. 2) Many binocular objects, as well as telescopic deep sky objects can be located by star-hopping using the constellations. 3) These constellations and bright stars are beautiful in their own right.

How far away is M31?

2.9 million lightyears away.

How many official constellations are there?

88

What is the head of the swan Cygnus marked by?

Albireo, a binary star.

What is the brightest star in Taurus?

Aldeberan. It marks the eye of the bull and if found among a V shape cluster called Hyades that makes up the face.

What is the second brightest star in Perseus?

Algol

What is special about the star Algol?

Algol is an eclipsing binary. It is therefore called the "Demon Star." Every 2.87 days Algol has an eclipse and its brightness drops for a few hours.

How far away is Altair from Earth? Deneb?

Altair is 17 lightyears away and Deneb is 1,500 lightyears away.

What constellation is Alpheratz apart of?

Andromeda.

What constellation is Altair apart of?

Aquila- the Eagle.

What star has the third highest proper motion of any star?

Arcturus

What is the brightest star in Boötes?

Arcturus; the fourth brightest star in Earth's night sky.

What constellation lies just north of Orion?

Auriga.

What constellation is found just east of Coma Berenices?

Boötes

What constellation is just west of Leo and lies halfway between Gemini and Leo?

Cancer.

What constellation is south and slightly east of Orion?

Canis Major- the big dog

What constellation is east of Orion and between Sirius and Pollux?

Canis Minor- the little dog

What is the brightest star in Auriga?

Capella, it is the 6th brightest star in the night sky. It is a multiple-star system.

What are some other constellations that can be found in the autumn sky?

Cassiopeia, Cepheus, Aquarius, Pisces, and Aries.

What are the 2 stars that dominate Gemini?

Castor and Pollux. Pollux is farther south and brighter than Castor.

What constellation is east and slightly north of Leo?

Coma Berenices.

What constellation is located just below of Sagittarius?

Corona Australis- the Southern crown.

What are some of the constellations that dominate the sky during the summer nights?

Corona Borealis, Hercules, Scorpius, Ophiuchus.

What constellation is Deneb apart of?

Cygnus- the swan

Which stars make up the lower arc of the bullhorn of Andromeda?

Delta Andromedae, Mirach, and ends at Almaak.

What constellation is Thuban in?

Draco- the dragon.

What stars does Orion's belt consist of?

From east to west the stars are Alnitak, Alnilam, and Mintaka.

What constellation lies to the east of Auriga?

Gemini

Asterism

Groups of bright stars that are not one of the official 88 constellations. It could be apart of a constellation.

What part of Ursa Major does the Big Dipper make up?

It forms the back half and tail of the bear.

Why is Epsilon Lyrae often called "Double-Double"?

It is a double star, but you can actually see both stars relatively clearly.

What is an eclipsing binary?

It is a star that looks like 1 star but is really 2 stars in a very tight orbit.

What constellation is the optical double Mizar and Alcor in?

It is in Ursa Major.

What constellation is the star Thuban in?

It is in the the Ursa Minor, between Mizar and Gamma Ursa Minoris.

When do we think that Orion was named?

It is mentioned in Job which was written around 2000 B.C.

Polaris is part of what asterism in what constellation?

It is part of the Little Dipper which is part of Ursa Minor.

What constellation is the spring sky dominated by?

Leo- the lion

What constellation is Vega apart of?

Lyra.

What global cluster is in Hercules?

M13

What galaxy does Andromeda contain?

M31; the brightest galaxy in the northern celestial hemisphere.

What stars make up the Great Square?

Markab, Scheat, Algenib, and Alpheratz.

Are their "gaps" between constellations?

No, there are no "gaps."

What is the constellation that will dominate the winter sky?

Orion

What constellations dominate the autumn sky?

Pegasus and Andromeda

Which constellation is west of Auriga and north of Pleiades?

Perseus.

What is the cluster to the west of Hyades in the winter sky?

Pleiades or the "7 sisters."

What is the brightest star in Canis Minor?

Procyon

What is the bottom star in the mane of the lion and the brightest star in Leo?

Regulus- a multiple star system.

What constellation is located south and slightly west of Aquila?

Sagittarius.

What is the brightest star in Canis Major?

Sirius- the "Dog Star."

Are there any other ways to name a star?

Stars also have proper names. We also use the Flamsteed system.

Hercules

Stars that make up the torso- Eta, Pi, Epsion, and Zeta Herculis.

What part of Cygnus is Deneb?

The "tail."

What clusters is Cancer home to?

The Beehive Cluster.

What well-known asterism is in the Ursa Major?

The Big Dipper

What asterism is found in Pegasus?

The Great Square.

What is very bright in the sky during the late summer sky?

The Milky Way.

What asterism does the Milky Way stream through?

The Summer Triangle

Proper motion

The angular speed of the star through the galaxy relative to the background stars.

What is Spica?

The blue star in the southeastern sky early in the spring evening.

Constellation

The brighter stars that form various shapes in our night sky.

Scorpius

The brightest star in Scorpius is Antares- "against Mars." The southeastern region is home to a number of star cluster- M6(Butterfly) and M7(Ptolemy; the brighter of the 2)

How does the Greek/Latin naming system work?

The brightness is identified by the Greek letter, such as Alpha is the brightest, Beta is the second brightest, etc. This is followed by the Latin possessive of the constellation name.

What constellation lies northwest of Orion in the winter sky?

The constellation Taurus.

Corona Borealis

The constellation just east of Boötes; the Northern Crown.

What is the eastern vertex of the triangle of Leo marked by?

The star Denebola; the second brightest star in Leo.

What are the 4 stars that represent Orion's shoulders and legs?

The upper east star is Betelgeuse, it makes Orion's right shoulder. The upper west star is Bellatrix, it makes Orion's left shoulder. The lower west star is Rigel, it makes Orion's left leg. The lower east star is Saiph, it makes Orion's right leg.

What are stars' names based on?

Their brightness and their constellation.

How many stars does Orion's sword consist of?

There are 3 stars oriented vertically.

Flamsteed system

This system uses a number that is in order of the star's RA from W to E, and then the Latin possessive.

What is a major constellation that is dominant in the spring ight sky?

Ursa Major- the big bear.

What 3 stars make up the Summer Triangle?

Vega(brightest), Deneb, and Altair

What constellation is Spica in?

Virgo