Space and Science

What exactly was this ‘interstellar visitor’?

Ashley Strickland
By Ashley Strickland, CNN
5 minute read
Updated 1:01 PM EDT, Wed June 27, 2018
This illustration shows a massive star on the brink of explosion.
This illustration shows a massive star on the brink of explosion.
Chuck Carter/Caltech
Meet the fastest asteroid in our solar system, which zips around the sun every 113 days. This artist's rendering shows the asteroid 2021 PH27 (top right) and Mercury (below) orbiting the sun.
Meet the fastest asteroid in our solar system, which zips around the sun every 113 days. This artist's rendering shows the asteroid 2021 PH27 (top right) and Mercury (below) orbiting the sun.
CTIO/NOIRLab/NSF/AURA/J. da Silva
A ghostly set of X-ray rings were found around a black hole with a companion star. These rings are created by light echoes.
A ghostly set of X-ray rings were found around a black hole with a companion star. These rings are created by light echoes.
CXC/U.Wisc-Madison/S. Heinz et al./Pan-STARRS/NASA
This image, taken with the Atacama Large Millimeter/submillimeter Array in Chile, shows the PDS 70 system 400 light-years away. This planetary system is still forming and still in the process of being formed. One of the planets in the system has a moon-forming disk around it.
This image, taken with the Atacama Large Millimeter/submillimeter Array in Chile, shows the PDS 70 system 400 light-years away. This planetary system is still forming and still in the process of being formed. One of the planets in the system has a moon-forming disk around it.
ALMA/ESO/NAOJ/NRAO/Benisty et al.
This image shows supernova 2018zd (pictured as the large white dot on the right), a new type of supernova called an electron capture. To the left is the galaxy NGC 2146.
This image shows supernova 2018zd (pictured as the large white dot on the right), a new type of supernova called an electron capture. To the left is the galaxy NGC 2146.
NASA/STSCI/J. Depasquale; Las Cumbres Observatory
This image from the STARFORGE simulation shows the "Anvil of Creation," a giant gas cloud with individual stars forming inside of it.
This image from the STARFORGE simulation shows the "Anvil of Creation," a giant gas cloud with individual stars forming inside of it.
From Northwestern University/UT Austin
Astronomers used NASA's Chandra X-ray Observatory to study the supernova remnant Cassiopeia A and discovered titanium, shown in light blue, blasting out of it. The colors represent other elements detected, like iron (orange), oxygen (purple), silicon (red) and magnesium (green).
Astronomers used NASA's Chandra X-ray Observatory to study the supernova remnant Cassiopeia A and discovered titanium, shown in light blue, blasting out of it. The colors represent other elements detected, like iron (orange), oxygen (purple), silicon (red) and magnesium (green).
T. Sato et al./RIKEN/CXC/NASA
The supermassive black hole at the center of the M87 galaxy, the first to ever be imaged, can now be seen in polarized light. Swirling lines reveal the magnetic field near the edge of the black hole.
The supermassive black hole at the center of the M87 galaxy, the first to ever be imaged, can now be seen in polarized light. Swirling lines reveal the magnetic field near the edge of the black hole.
European Southern Observatory
This image from the Sloan Digital Sky Survey shows the galaxy J0437+2456, which includes a supermassive black hole at its center that appears to be moving.
This image from the Sloan Digital Sky Survey shows the galaxy J0437+2456, which includes a supermassive black hole at its center that appears to be moving.
Sloan Digital Sky Survey
This artist's impression shows how the distant quasar P172+18 and its radio jets may have looked 13 billion years ago. The light from the quasar has taken that long to reach us, so astronomers observed the quasar as it looked in the early universe.
This artist's impression shows how the distant quasar P172+18 and its radio jets may have looked 13 billion years ago. The light from the quasar has taken that long to reach us, so astronomers observed the quasar as it looked in the early universe.
M. Kornmesser/European Southern Observatory
This image shows the vicinity of the Tucana II ultrafaint dwarf galaxy, captured by the SkyMapper telescope.
This image shows the vicinity of the Tucana II ultrafaint dwarf galaxy, captured by the SkyMapper telescope.
Anirudh Chiti/MIT
These images show two giant radio galaxies found with using the MeerKAT telescope. The red in both images shows the radio light being emitted by the galaxies against a background of the sky as it is seen in visible light.
These images show two giant radio galaxies found with using the MeerKAT telescope. The red in both images shows the radio light being emitted by the galaxies against a background of the sky as it is seen in visible light.
I. Heywood/Oxford/Rhodes/SARAO
This artist's conception of quasar J0313-1806 depicts it as it was 670 million years after the Big Bang. Quasars are highly energetic objects at the centers of galaxies, powered by black holes and brighter than entire galaxies.
This artist's conception of quasar J0313-1806 depicts it as it was 670 million years after the Big Bang. Quasars are highly energetic objects at the centers of galaxies, powered by black holes and brighter than entire galaxies.
NOIRLab/NSF/AURA/J. da Silva
Shown here is a phenomenon known as zodiacal light, which is caused by sunlight reflecting off tiny dust particles in the inner solar system.
Shown here is a phenomenon known as zodiacal light, which is caused by sunlight reflecting off tiny dust particles in the inner solar system.
Zolt Levay/Space Telescope Science Institute
This artist's impression of the distant galaxy ID2299 shows some of its gas being ejected by a "tidal tail" as a result of a merger between two galaxies.
This artist's impression of the distant galaxy ID2299 shows some of its gas being ejected by a "tidal tail" as a result of a merger between two galaxies.
M. Kornmesser/ESO
This diagram shows the two most important companion galaxies to the Milky Way: the Large Magellanic Cloud (left) and the Small Magellanic Cloud. It was made using data from the European Space Agency Gaia satellite.
This diagram shows the two most important companion galaxies to the Milky Way: the Large Magellanic Cloud (left) and the Small Magellanic Cloud. It was made using data from the European Space Agency Gaia satellite.
Laurent Chemin/ESA/Gaia/DPAC
The Blue Ring Nebula is thought to be a never-before-seen phase that occurs after the merger of two stars. Debris flowing out from the merger was sliced by a disk around one of the stars, creating two cones of material glowing in ultraviolet light.
The Blue Ring Nebula is thought to be a never-before-seen phase that occurs after the merger of two stars. Debris flowing out from the merger was sliced by a disk around one of the stars, creating two cones of material glowing in ultraviolet light.
NASA/JPL-Caltech/M. Seibert/K. Hoadley/GALEX Team
The red supergiant star Betelgeuse, in the constellation of Orion, experienced unprecedented dimming late in 2019. This image was taken in January using the European Southern Observatory's Very Large Telescope.
The red supergiant star Betelgeuse, in the constellation of Orion, experienced unprecedented dimming late in 2019. This image was taken in January using the European Southern Observatory's Very Large Telescope.
ESO/M. Montargès et al.
This is an infrared image of Apep, a Wolf-Rayet star binary system located 8,000 light-years from Earth.
This is an infrared image of Apep, a Wolf-Rayet star binary system located 8,000 light-years from Earth.
European Southern Observatory
An artist's illustration, left, helps visualize the details of an unusual star system, GW Orionis, in the Orion constellation. The system's circumstellar disk is broken, resulting in misaligned rings around its three stars.
An artist's illustration, left, helps visualize the details of an unusual star system, GW Orionis, in the Orion constellation. The system's circumstellar disk is broken, resulting in misaligned rings around its three stars.
ESO/L. Calçada, Exeter/Kraus et al.
This is a simulation of two spiral black holes that merge and emit gravitational waves.
This is a simulation of two spiral black holes that merge and emit gravitational waves.
N. Fischer, H. Pfeiffer, A. Buonanno, MPIGP, SXS Collaboration
This artist's illustration shows the unexpected dimming of the star Betelgeuse.
This artist's illustration shows the unexpected dimming of the star Betelgeuse.
ESO, ESA/Hubble, M. Kornmesser
This extremely distant galaxy, which looks similar to our own Milky Way, appears like a ring of light.
This extremely distant galaxy, which looks similar to our own Milky Way, appears like a ring of light.
Rizzo et al./ALMA/European Southern Observatory
This artist's interpretation shows the calcium-rich supernova 2019ehk. The orange represents the calcium-rich material created in the explosion. Purple reveals gas shed by the star right before the explosion.
This artist's interpretation shows the calcium-rich supernova 2019ehk. The orange represents the calcium-rich material created in the explosion. Purple reveals gas shed by the star right before the explosion.
Aaron M. Geller, Northwestern University
The blue dot at the center of this image marks the approximate location of a supernova event which occurred 140 million light-years from Earth, where a white dwarf exploded and created an ultraviolet flash. It was located close to tail of the Draco constellation.
The blue dot at the center of this image marks the approximate location of a supernova event which occurred 140 million light-years from Earth, where a white dwarf exploded and created an ultraviolet flash. It was located close to tail of the Draco constellation.
Northwestern University
This radar image captured by NASA's Magellan mission to Venus in 1991 shows a corona, a large circular structure 120 miles in diameter, named Aine Corona.
This radar image captured by NASA's Magellan mission to Venus in 1991 shows a corona, a large circular structure 120 miles in diameter, named Aine Corona.
From NASA/JPL
When a star's mass is ejected during a supernova, it expands quickly. Eventually, it will slow and form a hot bubble of glowing gas. A white dwarf will emerge from this gas bubble and move across the galaxy.
When a star's mass is ejected during a supernova, it expands quickly. Eventually, it will slow and form a hot bubble of glowing gas. A white dwarf will emerge from this gas bubble and move across the galaxy.
Mark Garlick/University of Warwick
The afterglow of short gamma ray burst that was detected 10 billion light-years away is shown here in a circle. This image was taken by the Gemini-North telescope.
The afterglow of short gamma ray burst that was detected 10 billion light-years away is shown here in a circle. This image was taken by the Gemini-North telescope.
International Gemini Observatory/K. Paterson/W. Fong/Northwestern University
This Hubble Space Telescope image shows NGC 7513, a barred spiral galaxy 60 million light-years away. Due to the expansion of the universe, the galaxy appears to be moving away from the Milky Way at an accelerate rate.
This Hubble Space Telescope image shows NGC 7513, a barred spiral galaxy 60 million light-years away. Due to the expansion of the universe, the galaxy appears to be moving away from the Milky Way at an accelerate rate.
Hubble Space Telescope/NASA/ESA/M. Stiavelli
This artist's concept illustration shows what the luminous blue variable star in the Kinman Dwarf galaxy may have looked like before it mysteriously disappeared.
This artist's concept illustration shows what the luminous blue variable star in the Kinman Dwarf galaxy may have looked like before it mysteriously disappeared.
L. Calçada/ESO
This is an artist's illustration of a supermassive black hole and its surrounding disk of gas. Inside this disk are two smaller black holes orbiting one another. Researchers identified a flare of light suspected to have come from one such binary pair soon after they merged into a larger black hole.
This is an artist's illustration of a supermassive black hole and its surrounding disk of gas. Inside this disk are two smaller black holes orbiting one another. Researchers identified a flare of light suspected to have come from one such binary pair soon after they merged into a larger black hole.
Robert Hurt/California Institute of Technology