55 Canari e, Helix Nebula and Messier 51

Observatory / Course Archives / ASTR 110 Fall 2019 / Wilson

55 Canari e

An Exoplanet is simply put, a planet that orbits a star which is not the Sun. The can be hard to see directly through the use of a telescope as their stars' bright light tend to hide them. As such, astronomers have found different ways to detect these exoplanet, one being the Doppler effect.

55 Cancri e is an exoplanet that orbits around the star 55 Cancri. It is located in the Cancer constellation and is about 40 light-years away from the earth. 55 Cancri e is the 5th planet found orbiting the star 55 Cancri. It orbits incredibly close to its star at around 3,532,320 miles and as such has an incredibly high temperature of 9200 degrees Fahrenheit. To put it in context, Mercury is 35,980,000 miles from the Sun and takes 87 days to orbit it. 55 Cancri e takes 18 hours to orbit its star! A fun fact about 55 Cancri e is that due to its very short orbital time of 18 hours, it has no days, it is tidally locked to its star meaning that its orbital period matches its rotational one. It also has one side constantly facing the star and the other in the darkness. It is also believed to be made out of diamonds valued at about $26.9 nonillion! Not a spelling mistake, there is something such as a nonillion. It is 30 zeros!

55 Cancri e is also double the radius of the Earth and has a mass of about 8 Earths! It is believed to be composed of mainly carbon, in the form of diamonds and graphite, as well as iron, silicon carbide and maybe silicates. It is believed by the international team of astronomers headed by Cavendish Lab Scientist Dr. Brice-Olivier Demory, that 55 Cancri e's hot side is so extreme that is has no atmosphere as it was evaporated! Temperatures of the various sides of 55 Cancri e vary greatly. On the hot side, temperatures could reach about 2,500°C, while its cool side is about 1,100°C.

Helix Nebula

A Nebula is simply, a giant cloud of dust and gas in space. Some nebulae are formed through the explosion of a dying start which emits gas and dust. Some are formed as a region where new starts are starting to form

The Helix Nebula is also known as NGC 7293 or "The Eye of God" is the closest Nebula to the Earth. It is approximately 650 light-years away. It is located in the Aquarius constellation. It came into being after a star, similar to our Sun, evolves into a red giant and got rid of its outer layers. The star's outer gasses, which are now floating in space, is illuminated by the central core of the star, which turns into a white dwarf after it eventually cools down. The Helix Nebula can be seen with binoculars and will appear hazy as a greenish cloud. It is surprisingly appearing as only one-half the Moon's diameter! That's smaller than I expected.

An interesting thing about the Helix Nebula is how it can appear on a wide spectrum, from ultraviolet to infrared in a similar manner but with some visible differences. When the Spitzer, an infrared capable telescope, was used to look at the nebula, it was seen to look like the eye of a monster with green and blue outer layers and a red pupil which is the final layers of gas blown out. This feature is awesome as based on the type of telescope one uses, you will experience and array of colors! The Helix Nebula was also the first planetary nebula discovered to have cometary knots which contain bright cusps and tails, extending away from the central star. It is believed to have about 20,000 cometary knots present!

Messier 51

A Galaxy is a collection of stars, gas, dust and dark matter all held together by the force of gravity. Their appearance and its composition are shaped through billions of years of activities from groups of stars and other galaxies.

Messier 51 or the Whirlpool Galaxy is a spiral galaxy that is located about 31 million light-years away in the Canes Venatici constellation. It was named after Charles Messier who was the first to discover the Whirlpool Galaxy in 1773. It has a unique spiral formation and can be seen easily using a small telescope in May and has a magnitude of 8.4. It appears face-on when looked at from Earth and it is one of the closest to our Galaxy, the Milky Way. The Messier 51 or M51 for short, is a magnificence sight to beyond in space. It contains spiral extension which are actual long lanes of stars and gas which are laced with dust. The spiral arms actually serve a meaningful purpose! They are the star-formation factories which compress hydrogen gas and creating cluster of new stars.

In the Hubble Telescope's imaging of Messier 51, the red that we see is the representation of infrared light and also hydrogen present within the giant star-forming regions. The blue color that can be seen is due to the presence of hot, young stars and the more yellowish colors is that of older stars. On interesting fact of M51, is that its gravitation is interacting with a small dwarf galaxy, NGC 5195. This interaction makes what can be called a pair of interacting galaxies in the sky. NGC 5195 has been gliding past M51 for hundreds of millions of years! The Whirlpool Galaxy is relatively an easy find. It is located 3.5 ° to the southeast of Alkaid and can be best seen with a low magnification telescope of at least 4-inchs.