The night sky is awash with stars, but which are the brightest? Discover what the brightest star in the night sky is tonight, & how to lớn find it.
What’s the brightest star in the night sky? You’re right, it’s Sirius (mag. -1.45), which coasts low above the southern horizon for most of us in the northern hemisphere during the cooler months.
Sirius is so bright that it’s not uncommon for people lớn mistake it for đời xe jupiter (maximum mag. About -2.7) or even Venus (maximum mag. About -5).
But, what if we were to change that question to lớn "what is the brightest star in the sky tonight?"
Sirus A & B by Fernando Oliveira De Menezes, Sao Paulo, Brazil. Equipment: CELESTRON C11, câmera 290mm
Astronomers also use the term absolute magnitude or luminosity, which is an object’s apparent magnitude if seen from a distance of 10 parsecs (32.6 lightyears: a parsec is 3.26 lightyears - for more on this read our guide lớn measuring distance in space).
In this article, we’re talking about the night’s brightest stars measured by apparent magnitude.What's the brightest star in the night sky tonight?
Arcturus shines brightly through the clouds in this image captured by Robin Buckmaster, Cenarth, Wales, 2011. Credit: Robin Buckmaster.
Around the over of February, the northern hemisphere’s second brightest star hops into the night. Arcturus (mag. -0.1) is the entire night sky’s fourth brightest star: an old red giant about 35 lightyears away.
To find it, just follow the curve of the Plough’s handle away from its blade (and while you're there, you might want to lớn take a look at stars Merak and Mizor & Alcor).
Arcturus is the next bright star we come to. It’s one of my favourite stars, và always makes me smile whenever I see it.
Sirius is still in the sky when Arcturus appears, though. It’s not until early April, when Sirius disappears, that Arcturus takes over & becomes the brightest star in the night sky.
Vega & surrounding stars through a telescope. Credit: Ade Ashford.
Next is bright, blueish Vega (mag. 0), which comes back to the night sky in early spring. Vega is in the constellation Lyra, the harp, and is also the brightest star in the Summer Triangle (one of our favourite summer constellations & asterisms).
Vega makes its way into the skies just as Sirius is leaving, và spends the spring & early part of the summer climbing high above our heads.
Vega by Jarrod Bennett, Mutxamel, Spain. Equipment: Canon 450D, 50mm lens, Vixen Polarie.
By September, when Arcturus’s time is up, Vega is almost due west, in the upper half of the sky.
The Summer Triangle’s stars are visible in the night sky into the early part of January, if you can believe it. This is when something interesting happens.
The stars of the Summer Triangle asterism. Star Vega (top left), is the 5th brightest star in the night sky. Altair can be seen below in the middle và Deneb is far left. Credit: A. Fujii
In December, while Vega is slowly making its exit, Sirius joins it, & both are in the sky at the same time. The trouble is, both of them are close to the horizon và can be difficult lớn see.
So, where does that leave us? It’s true that the brightest star in December is Vega until one night, when it becomes Sirius, but if they’re both too low to see easily, what bởi we do? We look straight overhead.
A starry nightscape looking towards the Yorkshire Three peaks. L lớn R - Whernside with a cảm ứng of aurora, Ingleborough with the constellation of Auriga và the bright star Capella, and Penyghent, with Perseus và the Pleiades. Credit: Pete Collins
High up at the very vị trí cao nhất of the sky is the stunning yellow Capella (mag. +0.05) in the constellation Auriga. An interesting thing about Capella is that it’s been there all along.
It’s the northernmost first-magnitude star, so far north that it’s circumpolar at the UK’s latitudes. That means it doesn’t rise and set like most other stars.
Instead, it’s in the sky every night of the year, where it appears to circle around Polaris, the North Star (for more on this, read our guide on how to lớn find the North Star.).
Though we tend to think of Capella as a wintertime star, look low khổng lồ the northern horizon in July. You’ll see it’s there then too (and is, incidentally, also one of my favourite summer stars).
The easy answer, then. The brightest star in the night sky tonight is 1 of 3:From January to April the brightest star in the night sky is Sirius.From April lớn September the brightest star is Arcturus.From September to December the brightest star is Vega, until Sirius comes back
And if Vega & Sirius are too low lớn see, take a look at Capella instead.Brightest stars in the southern hemisphere
Canopus. Credit: VW Pics/Universal Images Group via Getty Images
Things are different in the southern hemisphere sky. Canopus (mag. 0.65), in the constellation Carina, is the second brightest star in the southern sky, và sticks pretty close to lớn Sirius.
It’s only in the sky for a few nights in the southern autumn after Sirius leaves. Once it goes, it’s over lớn Rigel Kent (Alpha Centauri).
At mag. 0.1, it’s the sky’s third brightest & holds the title until Canopus comes back again in October.Find Arcturus, Capella và Vega
The Plough. Credit: Bernhard Hubl / CCDGuide.com
Back in the northern hemisphere, mid-May is a great time of year to lớn chase down the three stars that aren’t Sirius. They’re all in the night sky at the same time.
Arcturus is in the south, just off the kết thúc of the Plough’s handle, with Capella low toward the northwest and Vega in the northeast.
If you’re at sea or are otherwise lucky enough lớn have truly spectacular skies with clear views of the horizons, all four are in the sky toward the over of March: Sirius toward the southwest; Capella toward the northwest; Vega toward the northeast; & Arcturus in the east.