The Brightest Stars Next to the Moon

Introduction

When you look up at the night sky, some of the brightest objects near the Moon, which you might assume are stars, are actually planets in our solar system. These celestial objects usually look brighter than many stars because they are nearer to Earth and reflect sunlight really well.

In this article, we will look at the brightest stars and planets that appear next to the Moon. While the brightest lights near the Moon are usually planets like Venus, Jupiter, and Mars, there are also actual stars like Sirius, Canopus, and others that shine brightly. We'll learn why these planets appear so bright and distinguish them from the actual stars such as Sirius, Canopus, Arcturus, Betelgeuse, Rigel, and Aldebaran, and explore the features that make each one special. 

Understanding Apparent Brightness

When we look at stars in the night sky, how bright they appear doesn't only tell us how much light they actually give off. The perceived brightness is called "apparent brightness." This is different from "absolute brightness," which is how bright a star would look if all stars were the same distance from Earth.

Apparent vs. Absolute Brightness:

Apparent Brightness: This is how bright a star seems to us on Earth.
Absolute Brightness: This measures a star's true brightness at a standard distance, helping astronomers compare stars fairly.

What Affects Apparent Brightness?

The Moon and Its Celestial Neighbours

When you look at the night sky, some of the brightest lights near the Moon are often not even stars but planets. Planets appear brighter because they are closer to Earth and reflect sunlight off their surfaces or through their atmospheres. This makes them stand out more than most stars.

These planets move along paths or orbits. Since planets are closer to Earth than stars, they often look like they're moving through the sky and getting closer to the Moon. This is especially true for Venus and Jupiter, the brightest planets, which can outshine most stars.

The brightness of these planets changes depending on where they are in relation to Earth and the Sun. So, one day, the brightest one might become the dimmest.

Brightest Planets Near the Moon

Venus

Venus is often the brightest object in the night sky after the Sun and the Moon. For that reason, people often call it both a "Morning star" and an "Evening star." Venus's thick, reflective clouds make it visible even in twilight, and its orbit often places it near the Moon.

Jupiter

As the largest planet in our solar system, Jupiter is another bright spot often seen close to the Moon. Its massive size and reflective clouds allow it to shine brightly in the night sky, making it easily visible to the naked eye. Just like any planet in our solar system, Jupiter's place in the sky changes as it orbits the Sun, so it is not always near the Moon.

Mars

Mars, with its distinctive red coloring, is also a bright object often seen near the Moon. Mars's brightness varies as both Earth and Mars orbit the Sun. When Mars is directly opposite the Sun from Earth's perspective, it appears its brightest and often seems close to the Moon.

Saturn

You can still see Saturn with the naked eye near the Moon, especially when it is directly opposite the Sun from Earth. It is not as bright as Venus or Jupiter, though. Saturn's rings make it look brighter and unique, even though you can't see them without a telescope.

Brightest Stars Near the Moon

Sirius

Apart from planets, some actual stars do stand out near the Moon, and Sirius is the brightest one in our night sky. This massive, blue-white star is twice as bright as the second brightest star, Canopus. Though its closeness to the Moon is just a coincidence and depends on your location and timing, Sirius is so bright that you can easily see it near the Moon on some nights throughout the year.

A photo of binary star system of Sirius A and Sirius B, the arrow pointing at the smaller star Sirius B.

Canopus

Canopus is the second brightest star visible in the night sky and is seen best in the southern hemisphere. It belongs to the Carina constellation and is bright and relatively close to Earth, which makes it stand out. Canopus has a striking white color. Because it is far south, it often appears close to the Moon for people watching from southern locations.

An image of Canopus by Expedition 6.

Arcturus

Arcturus, a giant orange star in the constellation of Boötes, is another star that often appears near the Moon. It is one of the brightest stars in the northern hemisphere's sky. Arcturus is a red giant, much larger and older than our Sun, and its reddish hue helps distinguish it from other bright stars.

Other Bright Stars Close to the Moon

Betelgeuse, Rigel, and Aldebaran are three other brightest stars often seen near the Moon. Betelgeuse, in the Orion constellation, stands out with its red color and varies in brightness.

Rigel, also in Orion, glows brightly blue-white on winter nights, creating a striking contrast to the reddish Betelgeuse.

Aldebaran, in the Taurus constellation, glows orange and is easily recognizable as the eye of the bull in its star cluster.

Conclusion

1. Sirius, Canopus, Arcturus, Betelgeuse, Rigel, and Aldebaran are stars that shine brightly near the Moon. Each has unique characteristics, like color and brightness, that make it stand out when it appears close to the Moon.
2. Planets like Venus, Jupiter, Mars, and Saturn can sometimes be mistaken for stars because they often appear as some of the brightest objects near the Moon. That happens because of their reflective surfaces and closeness to Earth. However, because of their orbits around the Sun, their apparent brightness and position change over time.
3. The brightness of stars and planets depends on their distance, how much light they actually emit, and things like atmosphere and space dust. This helps explain why some objects look brighter than others in the sky.

References

1. Zombeck, Martin V. (2007). Handbook of space astronomy and astrophysics (Third ed.). Cambridge, UK: Cambridge University Press. pp. 75, 144–145.
2. Hoffleit, Dorrit; Jaschek, Carlos (1991). "The Bright star catalogue". New Haven.
3. Wikipedia - "List of brightest stars"