1. What is Parallax?

Parallax is the apparent shift in position of a nearby object against a distant background when viewed from different positions. In astronomy, it's used to measure distances to stars.

2. How Does the Calculator Work?

The calculator uses the parallax formula:

Where:

• parallax — Measured in arcseconds (")
• distance_pc — Distance in parsecs (pc)

Explanation: One parsec is defined as the distance at which an object has a parallax angle of one arcsecond.

3. Importance of Parallax Measurement

Details: Parallax is fundamental to astronomical distance measurements, forming the base of the cosmic distance ladder. It's most accurate for nearby stars (within a few thousand parsecs).

4. Using the Calculator

Tips: Enter the distance in parsecs. The calculator will compute the corresponding parallax angle in arcseconds.

5. Frequently Asked Questions (FAQ)

Q1: What is the practical limit of parallax measurements?
A: Current space telescopes like Gaia can measure parallax angles down to about 0.00001 arcseconds (100,000 parsecs).

Q2: Why is parallax measured in arcseconds?
A: Arcseconds are convenient units for the small angles involved in stellar parallax measurements (1 arcsecond = 1/3600 degree).

Q3: How does atmospheric affect parallax measurements?
A: Ground-based measurements are limited by atmospheric distortion, which is why space telescopes provide more accurate parallax measurements.

Q4: What's the relationship between parsecs and light-years?
A: 1 parsec ≈ 3.26 light-years. The parsec is more commonly used in professional astronomy.

Q5: Can this formula be used in reverse?
A: Yes, distance in parsecs can be calculated as 1/parallax (in arcseconds).