Sirius is one of the brightest stars visible from Earth. Approximately how far away is Sirius from Earth in $AU$ (astronomical units)?

• A. $8.6$ $AU$
• B. $1.6$ $AU$
• C. $93$ $AU$
• D. $548000$ $AU$

Answer: (D)

Verified step by step guidance

1. Understand that the distance to stars like Sirius is often given in light years or parsecs, but the problem asks for the distance in astronomical units (AU).
2. Recall that 1 light year is the distance light travels in one year, and 1 AU is the average distance from the Earth to the Sun.
3. Find the distance to Sirius in light years, which is approximately 8.6 light years.
4. Use the conversion factor: 1 light year is approximately equal to 63,240 AU.
5. Multiply the distance in light years by the number of AU per light year to get the distance to Sirius in AU: \(\text{Distance in AU} = 8.6 \times 63,240\).