# How Big is That Star?

## Stellar Dimensions

Name: __________________________________

Date: ______

Class: _______________________

You are going to be examining the sizes of stars. As a warm-up to measuring stars in a binary system, take a look at the data below showing the sizes of selected stars in our galaxy. Use the data in this table to fill out the rest of this worksheet.

## Dimensions of Typical Stars

 Star Radius(Solar radii) Density(Solar density) Mass(Solar mass) Supergiants Antares 776 0.00000004 20 Beta Lyrae 19.2 0.0014 9.7 Betelgeuse 1000 0.0000005 10 Deneb 96 0.00002 20 Gamma Cygni 67 0.00007 20 Rigel 78 0.00004 20 Giants Aldebaran 87 0.000006 4 Arcturus 35 0.00018 8 Beta Pegasi 40 0.00014 9 Capella 13 0.00096 2.1 Main Sequence Stars Our Sun 1.0 1.0 1.0 Altair 1.6 0.415 1.7 Barnard's Star 0.15 53.3 0.18 61 Cygni A 0.7 1.69 0.58 Hadar 22 0.0023 25 Krueger 60 0.35 6.30 0.27 MU-1 Scorpii 5.2 0.1000 14 Procyon A 2.6 0.102 1.8 Sirius A 1.9 0.335 2.3 White Dwarfs 40 Erdani B 0.018 71,000 0.41 Sirius B 0.022 90,000 0.99 Von Maanen's Star 0.007 47,000 0.14

## Answer the following

• List the stars in order based on the size of their radius, from smallest to largest.

• Now, next to each of the names in your list above, write the ratio of that star's radius to mass (measured in Suns).
• Find at least four of those stars on a constellation chart (provided by your teacher). List those five stars here along with saying which constellation they are in and make a sketch of the constellation with the location of the star.
• Explain the general relationship between radius and mass among this list of stars.

 A service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC