The winter hexagon or winter circle is six bright stars that are best seen in the night sky at this time. Sirius, Rigel, Aldebaran, Capella, Pollux, and Procyon – all of them can be seen in the winter sky right now. Just know where to look.

What is the winter hexagon?
In the temperate latitudes of the northern hemisphere, the most prominent stars change quite radically throughout the year. Some of them remain visible throughout the year. We can see others only in a few months. Right now, when winter reigns, the main decoration of the night sky, apart from the planets and the Moon, is the Winter Ring, or the Winter Hexagon.
The six stars that form it are very prominent indeed: α Canis Major Sirius, α Canis Minor Procyon, α Auriga Capella, α Tauri Aldebaran, β Ori Rigel, and β Gem Pollux. The figure they form is really big. The distance between Sirius and Capella, the two most distant stars, can be a third of the sky.
As for the shape, one might argue with the use of the word “circle”. The shape that the luminaries form is best described as a slightly elongated hexagon from the horizon to the zenith. From December to April, it is better to look at it in the first half of the night from 18 to 24 hours.

The way you find all the elements of the hexagon depends on when you look at the sky and how familiar you are with astronomy. If you’re just starting as an observer, it’s best to use the three stars of Orion’s Belt as a guide, which will travel from southeast to southwest all night long, rising high enough above the horizon.
If the line is drawn perpendicular to the horizon, the Rigel can be seen above it. If the line of the Belt is extended to the right, Aldebaran can be seen at a much greater distance. The main thing is not to confuse it with the much brighter Jupiter, which is now nearby.
Then you can continue the line connecting Aldebaran and the middle of the Orion’s Belt in the other direction and find a bright star above the horizon. This is Sirius. Together with Rigel, they form three neighboring vertices of a hexagon. So all that was left was to complete it in the mind.

Much higher and a little to the left of Aldebaran, you can find Capella, and to the left and above Sirius, Procyon. Finally, to the right of Procyon, but to the left of the Capella, we can find a pair of stars, one brighter than the other. These are Pollux and α Canis Major Castor.
However, if you are a complete beginner in astronomy and will still be looking at the sky right after sunset, it may be easiest to start with Sirius as an extremely bright star that will be just rising above the southeastern horizon at this time, and from there find Orion’s Belt and the rest of the objects using the method described above. Let’s take a look at what these six stars are.
Sirius
Sirius is the brightest star in the Earth’s sky. Its brightness can reach -1.46m. It is also one of the closest stars to us. The distance to it is 8.6 light-years. That’s why we see it so brightly.

It is a double system. The main star, whose light we mostly see, is a white main-sequence star. It is quite young and has an age of about 230 million years and a surface temperature of 9940 K. The star’s diameter is 1.71 solar masses, its mass is 2 Solar masses, and its luminosity is 25 times greater than that of the Sun.
Around the main component orbits a second one, a white dwarf with a mass roughly equal to our star, but thousands of times smaller in radius and luminosity. It makes one revolution around Sirius A in 50 years.
Procyon
Procyon is another binary star system close enough to us, located at a distance of 12 light-years from us. It is very similar to Sirius, except that the main star here is not a white class A star, but a white-yellow class F star.

Procyon A, the main component of the system, is 1.5 times heavier than the Sun and has an 86% larger radius. At the same time, its luminosity is 7.7 times higher than that of the Sun. The star is about 1.7 billion years old. The second star of the system is a white dwarf. Unlike Sirius B, it is much lighter: its mass is 60% of the solar mass. It makes a revolution around Procyon A in 40 years.
Capella
Capella is another star in the Winter Hexagon, which is a whole system. Two giant yellow luminaries with luminosities of 77 and 78 solar luminosities orbit each other at a distance of only 100 million kilometers, i.e. two-thirds of the distance from the Earth to the Sun.
Their masses are 2.7 and 2.6 solar masses, respectively, and their radii are 12 and 9 times larger than the solar radii. The age of the system is about 540-590 million years, and the distance from it to the Sun is 42 AU. There are also a couple of red dwarfs in the system.

Pollux
But Pollux, even though it is located not far from Castor, is a single star. It is an orange giant located 34 light-years away from us. The star’s mass is 47% higher than that of the Sun, and its age is about 1.19 billion years. This luminary has already exhausted its hydrogen reserves and has left the Main Sequence. As a result, it has been “blown up” to 9 radii of the Sun.
Interestingly, Pollux still has a planet. It is an incredibly large gas giant with a mass at least 2 times that of Jupiter. It is called Thestius and makes one revolution in 590 Earth days. Due to the star’s high luminosity, the temperature on its surface should be significantly higher than on Earth.
Aldebaran
Aldebaran is a red giant 65 light-years away. It shows us what the Sun will look like at the pre-final stage of its evolution – before it turns into a white dwarf.

Aldebaran is only 16% larger than the Sun by mass, but 45 times larger by radius and 439 times larger by luminosity. The star is 6.4 billion years old.
Rigel
Of all the stars that make up the Winter Hexagon, Rigel is the farthest from Earth. It is 860 light-years away and is a multiple system. The main luminary is a blue supergiant whose mass is 18 times greater than the solar mass and whose radius is 79 times greater than the solar mass. At the same time, its luminosity is 120 thousand times greater than that of the Sun.
In the shadow of such a giant are several other stars. Each of them, if it were at the same distance as the other stars of the Winter Hexagon, would be one of the brightest in the sky. But the fact of their existence was discovered only in the 19th century.

In general, the picture looks like this. Two blue stars with masses of 2.9 and 3.8 solar masses orbit a common center of mass in just 9.8 days. At the same time, this pair, together with the third blue star, forms a double system with a rotation period of 67 Earth years. Together, all three stars orbit Rigel A for 24 thousand years.
Other figures in the sky
It is worth recalling that the Winter Hexagon is an imaginary figure. Therefore, if desired, it is possible to distinguish others in the starry sky. For example, Procyon, Sirius, and α Ori Betelgeuse form the so-called Winter Triangle.
You can also connect Aldebaran, and Capella with lines. Castor, Pollux, Procyon, Sirius, Rigel, but do not close the circle on Aldebaran, but draw a line north to γ Ori Bellatrix, and from there to Betelgeuse. In this way, you can get a figure similar to the letter G.
In addition, it is impossible not to pay attention to Mars and Jupiter, which are now in the Winter Hexagon. The largest planet in the Solar System is paired with Aldebaran, and our red neighbor is the third to join Castor and Pollux.