May's Stellar Space Pictures
(Inside Science) -- Humanity's fascination with celestial objects in the night sky goes back thousands of years. The history of those objects goes back even further. This month, astronomers look back at that long history, using modern technology and ancient texts to observe the celestial bodies. The pictures from these studies build on previous generations' discoveries to look deeper into the cosmos, some of which may even predict future discoveries.
In 48 B.C., Chinese astronomers observed a stellar nova and recorded the following: “April of the first year of the first king, a ‘guest’ star as large as a melon with a green whitish hue located two stars to the east of the southern zodiac.” More than 2,000 years later, astronomers have finally located the remnants of that explosion -- at the center of the globular cluster Messier 22. The Göttingen-based team of astronomers was able to confirm one of the oldest observations of a stellar event outside of our solar system. Above is the modern picture (left), together with the Chinese ancient text, where the observation is highlighted (right). (ESA/Hubble and NASA, F. Gottgens (IAG)/The Chinese Text Project)
In a galaxy cluster not too far away lie stars banished from their galaxies. By combining 15 days' worth of X-ray data from NASA's Chandra X-Ray Observatory, astronomers saw stars stranded from their Fornax galaxy cluster, drifting some 60 million light-years away from Earth. They found that if a star in a binary goes supernova with enough force, it can send both it and its partner star into the vast emptiness outside galaxies. Above, the pairs are shown in purple X-ray light. (NASA/CXC/McGill University/X. Jin et al.)
Twenty-four years ago, Hubble changed our view of the night sky with the Hubble Deep Field image. This month, astronomers captured the Hubble Legacy Field image -- a mosaic of 16 years' worth of deep-field studies by the telescope. In looking at 265,000 galaxies that span across 13.3 billion years of time, the image essentially creates a “history book” of galaxies in the universe. (NASA/ESA)
This breathtakingly realistic image is actually a computer simulation depicting the birth of a protocluster of galaxies. Capturing a real image of these early stages of stellar growth may one day be possible with future telescopes. A new study by the Instituto de Astrofísica e Ciências do Espaço anticipates what those telescopes might see, such as very young galaxies with supermassive black holes at their cores. (TNG Collaboration)
NGC 4485 isn't your average galaxy. Pictured here, it is split between the serene environment of a typical galaxy on the left, and the violent explosions caused by the formations of young stars on the right. The young blue stars and bursting pink nebulas are a result of a near-collision with another galaxy -- NGC 4490 (not pictured in this crop). Millions of years ago, it glanced by NGC 4485, and the resulting gravitational pull sparked a cascade of new star births. (NASA/ESA)
