What are the 5 criteria for classifying stars?

Characteristics used to classify stars include color, temperature, size, composition, and brightness.

How many types of variable stars are there?

two
There are two basic types of variable stars: intrinsic variables, whose luminosity actually changes, and extrinsic variables, whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth. A star could be an intrinsic variable because it periodically swells and shrinks.

What is variable in a variable star?

A star is considered variable if its apparent magnitude (brightness) is altered in any way from our perspective on Earth. These changes can occur over years or just fractions of a second, and can range from one-thousandth of a magnitude to 20 magnitudes.

How do you classify a variable star?

Classifying Variable Stars

1. Eruptive – variation caused by flares or shell ejection; eg: flare stars, T Tau variables, RCBs, S Doradus stars.
2. Pulsating – radial or non-radial pulsation eg: Miras and semiregular variables, Cepheids, RV Tau stars.
3. Rotating – variation caused by starspots, magnetism, or changing shape.

What are the 3 main types of stars?

What are the two types of variable?

You can think of independent and dependent variables in terms of cause and effect: an independent variable is the variable you think is the cause, while a dependent variable is the effect.

What are examples of variable stars?

The Cepheids and RR Lyrae stars are typical examples of such variables. The explosive (or eruptive) variables include novas, supernovas, and similar stars that undergo sudden outbursts of radiant energy, which results in rapid brightening.

How do you observe a variable star?

Visual Observing A few variable stars can be followed entirely with the naked eye. 7×50 binoculars can observe over 100 variables. Almost all of the variable stars charted by the AAVSO can be monitored with a 20cm telescope.

What are the 4 main types of stars?

The Different Types of Stars

• Protostar. A protostar is what comes before a star has formed – a collection of gas that collapsed from a huge molecular cloud.
• T Tauri Stars.
• Main Sequence Stars.
• Red Giant Stars.
• White Dwarf Stars.
• Red Dwarf Stars.
• Neutron Stars.
• Supergiant Stars.

What are the 7 spectral classes of stars?

The stars are divided into 7 classes designated by the letters O, B, A, F, G, K, and M; the hottest stars (O and B) are blue-white in color, while the coolest (M) are red.

What are the 7 parts of the stars?

Seven Main Stages of a Star

• Giant Gas Cloud. A star originates from a large cloud of gas.
• Protostar. When the gas particles in the molecular cloud run into each other, heat energy is produced.
• T-Tauri Phase.
• Main Sequence.
• Red Giant.
• The Fusion of Heavier Elements.
• Supernovae and Planetary Nebulae.

What are the different classes of variable stars?

Many years ago, many classes of variable were described in terms of a prototype star; and astronomers would define new classes to encompass minor observational differences from known variables. Adding to the confusion, many variables would be in two or more classes depending on the criteria used to describe them.

What are the different types of DSCT stars?

DSCTC = Subspecies of DSCT with variations < 0.1 mag. L = Slow irregular variables. Many of these are reclassified after further study. LB and LC indicate giant and supergiant stars.

What makes a white star a variable star?

ACV = Alpha-2 CVn. White stars showing small variations due to large “starspots” generated by intense magnetic fields. Intense and variable spectral lines due to silicon, strontium, chromium and the lanthanide elements. The suffix “0” indicates rapid non-radial pulsations as well.

What kind of variation is a cataclysmic star?

Cataclysmic – variation caused by explosions of the star or an accretion disc. Includes dwarf novae, classic novae & supernovae. Eclipsing – binaries where one component passes in front of the other, as seen by the observer.