Once Astronomers Obtain the Apparent Magnitude for a Cepheid Variable

question 57

Multiple Choice

Once astronomers obtain the apparent magnitude for a Cepheid variable star by direct observation and the absolute magnitude from the period-luminosity relation, what do they need to use to find its distance?

• A) the H-R diagram (spectroscopic parallax)
• B) the distance-magnitude relationship
• C) the Stefan-Boltzmann relationship
• D) parallax

---

Definitions:

U.S. Ports

Key gateways for domestic and international trade, involving the management of goods entering or leaving the United States via sea, air, or land.

Customs Trade Partnership Against Terrorism (C-TPAT)

A voluntary supply chain security program led by U.S. Customs and Border Protection, focused on improving the security of private companies' supply chains with respect to terrorism.

U.S. Security Standards

Regulations and guidelines established within the United States to ensure the safety and security of information systems and data.

Compression

The reduction in volume or size of a material or data, often through applying pressure or using encoding techniques to decrease storage or transmission requirements.