2-11: Logarithms/Magnitudes ASTRO

These flashcards cover key concepts about logarithms and magnitudes in the context of astronomy, aiding in understanding and exam preparation.

What is the function of a logarithm?

A logarithm tells you how many times you have to multiply one number (the base) to reach another number.

What is the base for logarithms commonly used in astronomy?

The base is typically 10 (log base 10).

What is the logarithm of 100?

The log of 100 is 2, because 10 multiplied by itself twice equals 100.

What does an increase of 5 in magnitudes indicate regarding brightness?

A difference of 5 in magnitude corresponds to a factor of 100 in brightness.

How do you calculate apparent magnitude?

Apparent magnitude is determined by taking the logarithm of the flux received from an object.

What is absolute magnitude?

Absolute magnitude is the apparent magnitude of an object as seen from a distance of 10 parsecs.

What is the relationship between flux and magnitudes?

Every 5 steps in magnitude correspond to a factor of 100 in flux.

If a star has a magnitude of 1 and another has a magnitude of 6, how much brighter is the first star?

The magnitude 1 star is 100 times brighter than the magnitude 6 star.

What does it mean if an object has a negative magnitude?

A negative magnitude indicates that the object is very bright.

What is the distance modulus?

The distance modulus is the difference between absolute magnitude and apparent magnitude.

How do you calculate distance using the distance modulus?

Distance modulus equals 5 times the logarithm of the distance in parsecs minus 5.

What does a distance modulus of zero mean?

A distance modulus of zero means there is no difference between how bright you're seeing something and how bright it actually is.

How is apparent magnitude denoted?

Apparent magnitude is denoted with a lowercase 'm'.

How is absolute magnitude denoted?

Absolute magnitude is denoted with a capital 'M'.

What happens when you observe the brightest objects in the sky?

The brightest objects have lower magnitudes, typically ranging from magnitudes 0 to 2.

What is the significance of the phrase 'order of magnitude'?

An order of magnitude refers to a power of 10; being within an order of magnitude means being within a factor of 10.

What does it mean if an object has a larger apparent magnitude?

A larger apparent magnitude indicates that the object is dimmer.

What is the typical distance measure used in astronomy?

Parsecs are commonly used to measure astronomical distances.

What does RADAR stand for and how does it work?

RADAR stands for Radio Detection and Ranging; it sends out radio waves and measures the time it takes for them to bounce back to determine distance.

What is the relationship between speed, time, and distance?

Speed equals distance divided by time; knowing the speed of light allows calculation of distance based on echo timing.

How often do supernovae occur in observable galaxies?

Supernovae typically occur in observable galaxies somewhere at least once a day.