How Long Would It Take to Travel to Altair?

Altair is a white main-sequence star 16.7 light-years away in the constellation Aquila. It's the 12th brightest star in the night sky and spins so rapidly it's noticeably oblate.

Distance 16.73 light-years
Star Type White main-sequence (A7V)
Constellation Aquila
Apparent Magnitude 0.76

How Far Is Altair from Earth?

Altair is 16.73 light-years from Earth. That is about 158 trillion km (98.3 trillion miles), or 1.06 million astronomical units.

Distance to Altair in different units
Unit Distance
Light-years16.73
Kilometers158,000,000,000,000 km
Miles98,300,000,000,000 miles
Astronomical units (AU)1,060,000 astronomical units
Parsecs5.13

Light from Altair takes 16.73 years to reach Earth, so the light you see tonight left Altair 16.73 years ago.

Voyager 1, the fastest object humans have sent into deep space, travels at about 17 km/s. It would need about 295,000 years to cover this distance.

Time Dilation Formula Calculator

Spacecraft accelerates continuously throughout the journey. Realistic for ion drives or theoretical propulsion.

Distance to Altair
Speed vs Time
This chart shows how quickly you accelerate to a fraction of the speed of light over time.
Distance vs Time
Shows distance covered (in light-years) over time.
Traveler's vs Observer's Time
Shows how time experienced by the traveler differs from time on Earth.
Energy Requirement vs Distance
Shows the (simplified) energy requirements for maintaining relativistic travel as distance increases.
Doppler Shift vs Time
Shows how the Doppler effect changes observed wavelengths over time.
Velocity vs Distance
Shows how your speed changes as you travel further from your starting point.
Lorentz Factor vs Time
Shows how the Lorentz factor (γ) grows over time as relativistic effects increase.
Proper vs Observer Distance
Shows how distance measurements differ between the traveler's frame and the observer's frame.

Facts About Altair

Notable For: 12th brightest star, rotates rapidly causing oblate shape

Frequently Asked Questions

How long to travel to Altair?

At light speed, it would take 16.7 years to reach Altair. At 1g constant acceleration with deceleration, a traveler would experience about 9.2 years.

Why does Altair spin so fast?

Altair rotates every 8.9 hours, about 60 times faster than the Sun. This rapid rotation causes it to be noticeably flattened at the poles, with its equatorial diameter 20% larger than its polar diameter.

How far away is Altair?

Altair is 16.73 light-years from Earth, which is about 158 trillion km or 98.3 trillion miles. Light from Altair takes 16.73 years to reach us.

How many light-years is Altair from Earth?

Altair is 16.73 light-years from Earth. One light-year is about 9.46 trillion km, the distance light travels in one year. In parsecs, Altair is about 5.13 parsecs away.

Explore Similar Destinations

GJ 1002 15.78 light-years Gliese 876 15.24 light-years Eta Cassiopeiae 19.42 light-years

How to Use This Calculator

This time dilation calculator lets you enter a distance in light-years and acceleration in m/s² to see how time dilation affects your journey. It shows differences between traveler and observer times, maximum velocity, energy requirements, Doppler shift, Lorentz factor, and how distances vary between reference frames. Charts appear after you calculate.

Results

  • Traveler's Time: How much time the person on the spaceship experiences
  • Observer's Time: How much time passes on Earth during the journey
  • Maximum Velocity: The highest speed reached, as a fraction of light speed

Interactive Charts

  • Speed vs Time: How quickly you accelerate towards light speed
  • Distance vs Time: How far you've traveled over time
  • Traveler's vs Observer's Time: Compare time passage between Earth and spaceship
  • Energy Requirement vs Distance: How much energy is needed as you travel further
  • Doppler Shift vs Time: How light wavelengths change during your journey
  • Velocity vs Distance: Your speed at different distances
  • Lorentz Factor vs Time: How much time dilation increases with speed
  • Proper vs Observer Distance: How distance measurements differ between frames

What is Time Dilation?

Time dilation is an effect from Einstein's theory of special relativity. The faster you move, the slower time passes for you compared to someone standing still. At 90% of light speed, time passes about 2.3 times slower for the traveler than for someone on Earth.

What is the Time Dilation Formula?

The Time Dilation Formula is:

t' = t / √(1 - v²/c²)

Where:
t' = time measured by the observer (on Earth)
t = time experienced by the traveler
v = velocity of the traveler
c = speed of light (299,792,458 meters per second)