If you've been looking at the night sky for a while, like me, you might recognize some constellations and stars as old friends.
They might be welcomed when they first appear in the eastern sky at the beginning of a season. Then, you may wish them a fond farewell and they disappear into the west several months later. You might even be able to learn about the extraordinary characteristics and history of some stars over time. No two stars are exactly alike.
Let's now look at the personalities of some brightest stars visible in the evening sky.
Related: The brightest stars in the night sky: How and when to see them
More: November 2021, Night Sky: What can you see in this month?
This sky map shows the constellations and brightest stars in the night sky as seen from New York City. SkySafari app, image credit
A world's fair turn on'
Arcturus, the constellation Botes, is our first stop. It is the herdsman and is currently descending the sky just north of due west. This orange star with magnitude -0.05 is the fourth-brightest star in the nightsky and is currently located 36.7 light years from us.
Astronomers believed it to be 40 light-years from Earth in 1933.
Arcturus (Marpeankurric at the lower left) as well as the Milky Way above Lake Hart. (Image credit to Alex Cherney, CC BY–NC-ND
The Century of Progress exposition in Chicago that year saw starlight from Arcturus focused on a photocell attached at the 40-inch (102 cmimeters), Yerkes refracting microscope to turn on the lights of exposition. Astronomers at that time believed they were using radiation that had started heading towards Earth in 1893, 40 years before the World's Columbian Exposition.
Arcturus, a giant star, is approximately the same mass as our sun but is 25 times bigger and 170 times brighter.
Related: Starry Countdown: The Brightest Stars in Sky
Say cheese
Two views taken by NASA's Spitzer Space Telescope of the bright star Vega. Scientists discovered signs that a Neptune-sized exoplanet orbiting this star is scorching hot. (Image credit: NASA/JPL-Caltech/University of Arizona)
To the west of the zenith, which is the point directly overhead, is bright Vega, the lyre in the constellation Lyra. It is only a third of the brightness of Arcturus at magnitude +0.03, but its blue-white color makes them appear brighter.
Vega was first imaged on July 17, 1850 by William Bond and John Adams Whipple, using the daguerreotype technique. Vega was also the first star to have its distance measured using a technique called trigonometric paraallax. This was calculated in 1830s by Wilhelm von Struve.
It is only 25 light-years away from Earth and one of four very close stellar neighbors. It is about twice the size of the sun and approximately 40 times brighter than it.
One of the most stunning
The constellation Cygnus, also known as the Swan. Image credit: Larry Molnar (Calvin College).
Deneb, the constellation Cygnus' swan, however, is 2,600 light years away. Its distance cannot be measured trigonometrically because it is so far away.
Deneb is still ranked among stars with the first magnitude (magnitude+1.25) because of its intrinsic luminosity. This luminosity is approximately 5,000 times higher than Vega's and places it among the most visually striking stars. It is the 19th brightest star in our sky. This makes it very similar to Rigel in Orion, a hunter, and many other hot young stars in our winter sky.
An "outstretched" sun
Altair is a fast spinning star. Its equator has a diameter that is at least 14 per cent larger than its poles. (Image credit: NASA/JPL/Caltech/Steve Golden)
Altair is the closest bright star to our evening sky, at 16.7 light years away. There are only 50 known stars, and many-star systems that are closer.
Altair, the brightest luminary of the constellation Aquila (magnitude +0.77), forms the famous Summer Triangle with Vega & Deneb. It is nearly twice the size of our sun and eleven times more luminous.
It is interesting that Altair's rotational period only takes nine hours, whereas our sun takes approximately 25 days to complete a turn on its axis. Altair's spin is so fast that it is an oblate Spheroid, and noticeably flattened at the poles.
A colossal stellar beacon
Antares, a supergiant red star in the constellation Scorpius shines as the bright-red spark at the center. (Image credit: Babak Tafreshi/TWAN)
We can see Antares in the constellation Scorpius low in the southwest. It is a scorpion that is getting ready to leave the night sky. The star is the largest visible to the naked eye and would orbit the sun if it were at its center.
Antares is 600 light-years away. It shines at magnitude +0.9 most of the time, but can fluctuate by several tenths or more at irregular intervals.
It's lonely and dusty
This ALMA radio telescope image clearly shows the dusty ring surrounding Fomalhaut's star. It is approximately 12 billion miles (20 miliarde kilometers) away from the star, and 1.2 billion (2 million km) wide. (Image credit: ALMA (ESO/NAOJ/NRAO); M. MacGregor)
Fomalhaut is the brightest star in the "watery" portion of the sky, and it can be found at the mouth of Piscis Autrinus, a southern fish. Fomalhaut's +1.16 magnitude makes it more prominent than the nearby bright stars. This is why it's often called "the single one."
Fomalhaut lies 25 light-years from Earth. It is almost twice the size of the sun and approximately 17 times brighter than it. Also, it is surrounded by a disc of dust and debris. This disk was thought to be an extrasolar world in 2008.
It's winter!
Slooh Observatories' bright North Star, Polaris Slooh Image Credit
For those who live in the mid-northern latitudes, the harbinger for the brilliant winter parade is finally here. Capella, which is located north of +44 degrees is circumpolar. It circles around Polaris, The North Star, all year. It is the sunniest of autumn's bright stars. A double star with components that are slightly cooler, but significantly brighter, and larger than our own star, it is also one of the most sunny.
Capella is 42.9 light years away and is magnitude +0.08 fainter than Vega. Moreover, Capella is on the opposite side of the pole. At about the same distance, an imaginary line connecting the stars would almost pass through Polaris. One star is higher than the other, and as we turn toward the fall, Vega can be seen high above the ground while Capella can barely be seen.
Three months from now, when it is likely to be even colder, Capella will be at the top of frosty skies in mid-evening while Vega will soon be out of view in the northwest.
Joe Rao is an instructor at the Hayden Planetarium in New York. He is a writer on astronomy for Natural History magazine and the Farmers' Almanac, among other publications. Follow us on Facebook and Twitter @Spacedotcom
