Humanity has observed the universe with a diameter of up to 93 billion light-years, an unimaginably vast expanse. A light-year is the distance that light travels in one year, roughly equivalent to 9.461 trillion kilometers.
Within this vast expanse, scientists have discovered numerous celestial bodies such as galaxies, nebulae, stars, and planets. The universe is filled with diverse and unique objects, each distinct and not blending into one another. Below are some extraordinary highlights from this cosmic landscape.
Binary Star System Swift J1357.2
Swift J1357.2-0933 lies approximately 5,000 light-years away from Earth in the constellation Virgo and is one of the closest peculiar structures to us. Scientists still know little about this type of celestial object since we haven’t encountered other examples.
The hypothesis suggests that this object consists of two stars in a binary star system orbiting around a black hole with a mass similar to that of a star. The two stars orbit each other with the shortest orbital period ever recorded: only 2.8 hours.
Contrary to common belief, a black hole does not suck in all matter around it; it only swallows unfortunate objects that venture too close, reaching the region known as the event horizon. Therefore, the members of this binary star system remain undisturbed, orbiting peacefully around the black hole.
However, the central black hole still needs to feed on something, and so the wandering matter is drawn in, forming a disk that wraps around the structure of Swift J1357.2, creating a thin layer that can change in brightness depending on the positions of the two stars.
Hanny’s Voorwerp
In the image is IC 297, a spiral galaxy located 650 million light-years away from Earth in the constellation Leo Minor. But the notable entity lying just below it, called Hanny’s Voorwerp, is one of the most peculiar structures ever to exist.
Hanny’s Voorwerp and IC 2497 were captured by the WFC3 instrument of NASA’s Hubble Space Telescope. Photo: NASA.
This structure has left astronomers, including those using the Hubble Space Telescope, astounded and puzzled. Not only is it extraordinary, but it is also immense, with a diameter equivalent to that of the Milky Way, spanning up to 100,000 light-years.
The core of Hanny’s Voorwerp is an inactive quasar situated within IC 297. Occasionally, it emits a dark blue light, creating a ghastly-looking spiral stream of matter that adds to the uniqueness of the structure.
Horologium-Reticulum Supercluster
This massive structure resembles a supergiant cosmic monster, housing over 350,000 individual galaxies, including 30,000 large galaxies and 5,000 groups of galaxies containing 300,000 dwarf galaxies. It lies approximately 700 million light-years away from Earth, measured from its closest edge.
The observation records the galaxies that humans have observed (white circles) and the galaxies predicted to exist (red circles) within this super galaxy cluster. Photo: Melanie Johnston-Hollitt, Mitsuyuki Sato.
The entirety of this structure is so vast that we are still uncertain of its extent and where it ends. Observations indicate that it stretches at least 1.2 billion light-years in length and spans 550 million light-years horizontally.
At the heart of the Horologium-Reticulum supercluster is Abell 3266, one of the most massive regions of galaxies in our local group. By chance, massive gas clouds spanning over 5 million light-years are rapidly approaching the cluster, recreating a period of star formation for us to observe and understand further.