Ceres, Horsehead Nebula, Messier 64 (The Black-Eye Galaxy)

Observatory / Course Archives / ASTR 110 Fall 2019 / Park

Ceres

The picture above is a dwarf planet called Ceres. Dwarf planet is a planet that almost became a planet but not quite. Ceres is located at the asteroid belt between Mars and Jupiter. It contains 25% of the asteroid belt's total mass. Ceres was first found in 1801 by Giuseppe Piazzi and got its name from a Roman Goddes of harvest. Ceres was first classified as the missing planet. However, in 2006 it was declared to be the only dwarf planet located in the inner planet orbits.

Ceres has a radius of 296 miles (476 kilometers) which is 1/13 radius of the Earth. It is 2.8 AU away from the Sun (257 million miles or 413 million kilometers) which takes 22 seconds for sunlight to travel to Ceres. Ceres has an orbit of 1682 Earth days or 4.6 Earth years and a single rotation of 9 hours. The scientists say that this planet was formed 4.5 billion years ago, and 4 billion years ago Ceres settled into its current position. Ceres contains very similar characteristics to its neighbor terrestrial planet but is less dense. It is similar because it has a spherical shape due to its own gravity. Due to all these similar characteristics with terrestrial planets, it has a nickname called a minor planet. Ceres contains 25% water in its mass where most of them are located in the mantle and has a thin water vapor of atmosphere. It is made up of 60% rock and 40% ice/water. An interesting fact is that Ceres lacks crater which means that it might have active volcanoes in Ceres, but not like the ones on Earth. It is a volcano that is formed by cryovolcanism which is a volcanic activity where molten ice and water replace the molten silicate rocks. It basically erupts ice saltwater.

Horsehead Nebula

This picture above is a nebula called Horsehead nebula or Barnard 33. It is part of the larger complex of nebulae called the Orion molecular cloud which is with the constellation of Orion. It is formed from the collapse of interstellar clouds which contains a lot of cold ionized hydrogen. The clouds of hydrogen are very dense and thick, so it blocks off lights that are coming behind it. The cloud core is from the parental cloud and it does not create too many stars now. If it does create new stars, it is usually low mass stars. The reddish glowing light is emitting heat and radiation to glow the Horsehead nebula, and it is coming from a nearby bright stars called Sigma Orionis.

Horsehead Nebula is first found by Scottish astronomer called Williamina Fleming in 1888. He found it from the observatory located at Harvard University. Horsehead nebula is around 1600 light-years away from the Earth and the astronomers say that the nebula will last for another 5 billion years. Its apparent size is 8x6 arcminutes.

Messier 64

The picture above is a picture of the Messier 64 galaxy. It is also known as black eye galaxy or evil eye galaxy. It is a spiral galaxy that is located at constellation called Coma Berenices and belongs to a galaxy group called M94 group or Canes Venatici I cloud. It is known for its huge light-absorbing black band of dust around the bright central area. The astronomers say that there are around 100 billion stars and there is no evidence supernova in the galaxy. There is an interesting fact about Messier 64. It is that there are two disks of around equal masses that are counter-rotating each other. The astronomers said that the inner disk is 3000 light-years in radius and outer disk is 40,000 light-years in radius, and the two disks are counter-rotating at a speed of 300 km/s. The rubbing and of the two disks are causing intense formations of new-born stars in the region where the gases are colliding and compressing. Some astronomers predict that the possible explanation of the two disks counter-rotating is from a collision of a gas-rich small galaxy and a nearby cloud of gases. They predict that this happened around one billion years ago. The pink clouds are glowing hydrogen gases which became fluoresce when it is exposed to ultraviolet light from newly formed stars. This shows that new stars are kept on being born from the collision and compression of the gas as the two disks counter rotate.

Messier 64 was first discovered by English astronomer Edward Pigott, on March 23, 1779. However, a few days later, on April 4, 1779, German astronomer Johann Elert Bode discovered Messier 64 again. Then he was one to publish it first until 2002, the astronomers found out about Edward Pigott and gave him the credit back. Also, William Herschel was first to discover the black band of dust around the galaxy. Messier 64 is 24 million light-years away from Earth and it has a line of sight of 60 degrees. It has a visual brightness of 8.5 mag and an apparent magnitude of 9.8. It also has an apparent size of 10.71 x 5.128 arcminutes with a diameter of 70,000 light-years.