Art of the Universe

Observatory / Course Archives / ASTR 110 Fall 2019 / Song

Dark Planet (TrES-2b)

In the constellation Draco, the darkest known exoplanet identified as TrEs-2b exists 750 light-years away. It was found by the Trans-Atlantic Exoplanet Survey (TrES), a network of telescopes used to detect exoplanets. TrES used the transit method, a method which detects the dimming of a star as a planet passes between it and the Earth. TrEs-2b orbits its star in 60 hours from just three million miles away from its star. To give a sense of scale, Mercury, the planet that is closest to the Sun in our solar system, is 35.98 million miles away from the Sun. Despite TrES-2b's proximity to its star, astronomers believe that this Jupiter-sized gas giant reflects less than one percent of its star's light, causing the exoplanet to look black with a faint red glow.

The reasoning behind TrES-2b's darkness remains a mystery for scientists. Some suggest that the exoplanet's abundance of gaseous sodium and titanium oxide, chemicals that absorb light, may have a part in proving its black color; however, there are notions that something beyond the chemicals must explain the extremity of the exoplanet's darkness.

Bubble Nebula (UGC 7635)

The Bubble Nebula was first discovered in 1787 by English astronomer William Herschel. Though it was first classified as a planetary nebula, it is now classified as an emission nebula because of its distinct layers of gas. It resides in the constellation Cassiopeia about 7,100 to 11,000 light-years away.

It was created by the stellar winds and radiation of the massive star BD+602522; the winds are represented in yellow inside the nebula. Beside the massive star resides a giant molecular cloud which is represented in yellow next to the nebula. When the gas in the star's atmosphere gets hot, dust and gas escape and pick up the interstellar gas in front of it. The material moves away from the star and interacts with the molecular cloud nearby which forms the nebula's bubble shape. The molecular cloud helps keep the round shape by preventing the bubble from expanding. Radiation causes the nebula to glow.

Tadpole Galaxy (Arp 188)

Arp 188, The Tadpole Galaxy, gets its name from its distinct tail shape that is about 280,000 light-years long. It exists in the constellation Draco about 420 million light-years away and is identified as a disrupted barred spiral galaxy. The galaxy's spiral arms contain massive blue stars that are 10 times hotter than our Sun.

The tail shape of Arp 188 proves its interaction with another galaxy; the tail was formed when the spiral galaxy collided with an intruder galaxy around 100 million years ago. As the smaller intruder galaxy passed, its forces drew out a trail of blue stars and gas from the larger galaxy. As the galaxy grows older, its tail will most likely break apart into smaller companion galaxies that will orbit the galaxy's center.