What is the brightest star and how far from it would we have to be to get the same light we get from theSun?

Question

Also how far away from this brightest of stars would we have to be to experience the same heat levels? Thanks

Answer 1

cfpops is in the ballpark but I'm not sure if he hit the ball. His methodology is on the right track, but luminosity is not just a function of temperature, it is a function of both temperature and surface area. L is proportional to 4(pi)R^2 * T^4. So size matters!
A good example would be Alberio. One of the two stars is blue and the other is yellow, but the yellow one is brighter than the blue one. Why? Because it is a giant and is many times larger than its hotter companion.
In addition to the above, I think it should also be pointed out that while Sirius has the highest apparent magnitude of all the stars in the night sky, it is by no means the brightest by way of absolute magnitude. Three candidates that immediately come to mind would be Antares, Betelgeuse and Deneb. And if you want to tally up multiple stars, Castor is a 6 star system.
Having said that, cfpops is certainly going in the right direction, he just missed at the first pitch.

Answer 2

The brightest star in the sky is Sirius A. it has an absolute magnitude of -1.44 (compared to the sun which has an absolute magnitude of 4.8)

It works out we'd have to be 10^-4 parsecs from Sirius to experience the light we see from the sun.
Which 0.000326163626 light years.
Which is 3.08568025 × 10^12
Which is about 2 billion miles
meters. Which is

Answer 3

Sirius, the brightest star in the night sky as seen from Earth, is approximately 23 times more luminous than the Sun.

The surface temperature of a main sequence star is determined by the rate of energy production at the core and the radius of the star. Massive stars can have surface temperatures of 50,000 K. Smaller stars such as the Sun have surface temperatures of a few thousand degrees. Red giants have relatively low surface temperatures of about 3,600 K, but they also have a high luminosity due to their large exterior s.urface area

--- From Wikipedia, http://en.wikipedia.org/wiki/Stars

The name of this star comes from the Latin Sīrius, from Greek Σείριος (Seirios, "glowing" or "scorcher"). As the major star of the "Big Dog" constellation, it is often called the "Dog Star".

Sirius (α CMa / α Canis Majoris / Alpha Canis Majoris) is the brightest star in the night-time sky, with a visual apparent magnitude of −1.47. This binary star system consists of a blue-white main sequence dwarf star and a faint white dwarf companion. It is located in the constellation Canis Major.

Temperature: 9,900 (for A-star) and 25,200 (for B-star), both are in temperature units of Kelvins
--- From Wikipedia, http://en.wikipedia.org/wiki/Sirius

The surface of the Sun is close to 5,785 Kelvins
--- From Wikipedia, http://en.wikipedia.org/wiki/Sun

Radiant emittance inwatts per square metre (W/m^2) is the power emitted from a surface.
--- From Wikipedia, http://en.wikipedia.org/wiki/Radiant_energy

Now, some assumptions and calcuations:
* Assume that the total radiant emittance from the two binary stars that make up Sirius = sum of both stars. Then the total temperature of Sirius = 9,900 + 25,200 = 35,100 Kelvin

Then, Sirius is = 35,100 K/5,785 K times hotter than the Sun =
6.07 times hotter than the sun.

Since temperature is inversely proportional to distance, we can write the equation:

Sirius remote temp = Sirius temp / metres^2 from Sirius
Sun remote temp = Sun temp / metres^2 from Sun

We can also say from the question statement that these two equations are equal:
Sirius temp / metres^2 from Sirius = Sun temp / metres^2 from Sun

Then, rearranging:
Sirius temp/Sun temp = Metres^2 from Sirius/Meters^2 from Sun.

We calculated the left side of the equation earlier, so now:
6.07 = Metres^2 from Sirius/Meters^2 from Sun

Take the square root on both sides of the equation:
2.46 = metres from Sirius/metres from Sun

So, you would have to be 2.46 times further away from Sirius to experience the same temperature as we are from the Sun.

Hope this helps!