Analysis of information sources in references of the Wikipedia article "ʻOumuamua" in English language version.
As its albedo is unknown, we do not describe 1I/ʻOumuamua as consistent with Tholen (1984) P type.
The discovery epoch photometry implies a highly elongated body with radii of ~200×20 m when a comet-like geometric albedo of 0.04 is assumed. Here we report spectroscopic characterisation of ʻOumuamua, finding it to be variable with time but similar to organically rich surfaces found in the outer Solar System. The observable ISO population is expected to be dominated by comet-like bodies in agreement with our spectra, yet the reported inactivity implies a lack of surface ice. We show this is consistent with predictions of an insulating mantle produced by long-term cosmic ray exposure. An internal icy composition cannot therefore be ruled out by the lack of activity, even though ʻOumuamua passed within 0.25 au of the Sun.
We find that ʻOumuamua is 'cigar-shaped', if close to its lowest rotational energy, and an extremely oblate spheroid if close to its highest energy state for its total angular momentum.
No evidence of artificial signals emanating from the object so far detected by the Green Bank Telescope, but monitoring and analysis continue. Initial data are available for public inspection in the Breakthrough Listen archive
As its albedo is unknown, we do not describe 1I/ʻOumuamua as consistent with Tholen (1984) P type.
The discovery epoch photometry implies a highly elongated body with radii of ~200×20 m when a comet-like geometric albedo of 0.04 is assumed. Here we report spectroscopic characterisation of ʻOumuamua, finding it to be variable with time but similar to organically rich surfaces found in the outer Solar System. The observable ISO population is expected to be dominated by comet-like bodies in agreement with our spectra, yet the reported inactivity implies a lack of surface ice. We show this is consistent with predictions of an insulating mantle produced by long-term cosmic ray exposure. An internal icy composition cannot therefore be ruled out by the lack of activity, even though ʻOumuamua passed within 0.25 au of the Sun.
We find that ʻOumuamua is 'cigar-shaped', if close to its lowest rotational energy, and an extremely oblate spheroid if close to its highest energy state for its total angular momentum.
Such outgassing is a behaviour typical for comets and contradicts the previous classification of ʻOumuamua as an interstellar asteroid. "We think this is a tiny, weird comet," commented Marco Micheli. "We can see in the data that its boost is getting smaller the farther away it travels from the Sun, which is typical for comets."
As its albedo is unknown, we do not describe 1I/ʻOumuamua as consistent with Tholen (1984) P type.
The discovery epoch photometry implies a highly elongated body with radii of ~200×20 m when a comet-like geometric albedo of 0.04 is assumed. Here we report spectroscopic characterisation of ʻOumuamua, finding it to be variable with time but similar to organically rich surfaces found in the outer Solar System. The observable ISO population is expected to be dominated by comet-like bodies in agreement with our spectra, yet the reported inactivity implies a lack of surface ice. We show this is consistent with predictions of an insulating mantle produced by long-term cosmic ray exposure. An internal icy composition cannot therefore be ruled out by the lack of activity, even though ʻOumuamua passed within 0.25 au of the Sun.
We find that ʻOumuamua is 'cigar-shaped', if close to its lowest rotational energy, and an extremely oblate spheroid if close to its highest energy state for its total angular momentum.
A point of light centered in this 5 minute exposure recorded with the William Herschel Telescope in the Canary Islands on October 28 ... Faint background stars appear streaked because the massive 4.2 meter diameter telescope is tracking the rapidly moving A/2017 U1 in the field of view.
It was also determined to be rocky and metal rich, and to contain traces of tholins – organic molecules that have been irradiated by UV radiation.Also here [1] Archived 22 December 2017 at the Wayback Machine at Phys.org
The discovery epoch photometry implies a highly elongated body with radii of ~200×20 m when a comet-like geometric albedo of 0.04 is assumed. Here we report spectroscopic characterisation of ʻOumuamua, finding it to be variable with time but similar to organically rich surfaces found in the outer Solar System. The observable ISO population is expected to be dominated by comet-like bodies in agreement with our spectra, yet the reported inactivity implies a lack of surface ice. We show this is consistent with predictions of an insulating mantle produced by long-term cosmic ray exposure. An internal icy composition cannot therefore be ruled out by the lack of activity, even though ʻOumuamua passed within 0.25 au of the Sun.
So far limited observations of ʻOumuamua, using facilities such as the SETI Institute's Allen Telescope Array, have turned up nothing.
As its albedo is unknown, we do not describe 1I/ʻOumuamua as consistent with Tholen (1984) P type.
The discovery epoch photometry implies a highly elongated body with radii of ~200×20 m when a comet-like geometric albedo of 0.04 is assumed. Here we report spectroscopic characterisation of ʻOumuamua, finding it to be variable with time but similar to organically rich surfaces found in the outer Solar System. The observable ISO population is expected to be dominated by comet-like bodies in agreement with our spectra, yet the reported inactivity implies a lack of surface ice. We show this is consistent with predictions of an insulating mantle produced by long-term cosmic ray exposure. An internal icy composition cannot therefore be ruled out by the lack of activity, even though ʻOumuamua passed within 0.25 au of the Sun.
We find that ʻOumuamua is 'cigar-shaped', if close to its lowest rotational energy, and an extremely oblate spheroid if close to its highest energy state for its total angular momentum.
Astronomers are now certain that the mysterious object detected hurtling past our Sun last month is indeed from another solar system. They have named it 1I/2017 U1 (ʻOumuamua) and estimate it could be one of 10,000 others lurking undetected in our cosmic neighbourhood.
Green Bank telescope in West Virginia will listen for radio signals from ʻOumuamua, an object from another solar system ... "Most likely it is of natural origin, but because it is so peculiar, we would like to check if it has any sign of artificial origin, such as radio emissions," said Avi Loeb, professor of astronomy at Harvard University and an adviser to the Breakthrough Listen project. "If we do detect a signal that appears artificial in origin, we'll know immediately." ... While many astronomers believe the object is an interstellar asteroid, its elongated shape is unlike anything seen in the asteroid belt in our own solar system. Early observations of ʻOumuamua show that it is about 400m long but only one tenth as wide. "It's curious that the first object we see from outside the solar system looks like that," said Loeb.
Its dark and reddened surface is also an indication of tholins, which are the result of organic molecules (like methane) being irradiated by cosmic rays for millions of years.
It was also determined to be rocky and metal rich, and to contain traces of tholins – organic molecules that have been irradiated by UV radiation.Also here [1] Archived 22 December 2017 at the Wayback Machine at Phys.org
A point of light centered in this 5 minute exposure recorded with the William Herschel Telescope in the Canary Islands on October 28 ... Faint background stars appear streaked because the massive 4.2 meter diameter telescope is tracking the rapidly moving A/2017 U1 in the field of view.
So far limited observations of ʻOumuamua, using facilities such as the SETI Institute's Allen Telescope Array, have turned up nothing.
Astronomers are now certain that the mysterious object detected hurtling past our Sun last month is indeed from another solar system. They have named it 1I/2017 U1 (ʻOumuamua) and estimate it could be one of 10,000 others lurking undetected in our cosmic neighbourhood.
Such outgassing is a behaviour typical for comets and contradicts the previous classification of ʻOumuamua as an interstellar asteroid. "We think this is a tiny, weird comet," commented Marco Micheli. "We can see in the data that its boost is getting smaller the farther away it travels from the Sun, which is typical for comets."
The discovery epoch photometry implies a highly elongated body with radii of ~200×20 m when a comet-like geometric albedo of 0.04 is assumed. Here we report spectroscopic characterisation of ʻOumuamua, finding it to be variable with time but similar to organically rich surfaces found in the outer Solar System. The observable ISO population is expected to be dominated by comet-like bodies in agreement with our spectra, yet the reported inactivity implies a lack of surface ice. We show this is consistent with predictions of an insulating mantle produced by long-term cosmic ray exposure. An internal icy composition cannot therefore be ruled out by the lack of activity, even though ʻOumuamua passed within 0.25 au of the Sun.
Green Bank telescope in West Virginia will listen for radio signals from ʻOumuamua, an object from another solar system ... "Most likely it is of natural origin, but because it is so peculiar, we would like to check if it has any sign of artificial origin, such as radio emissions," said Avi Loeb, professor of astronomy at Harvard University and an adviser to the Breakthrough Listen project. "If we do detect a signal that appears artificial in origin, we'll know immediately." ... While many astronomers believe the object is an interstellar asteroid, its elongated shape is unlike anything seen in the asteroid belt in our own solar system. Early observations of ʻOumuamua show that it is about 400m long but only one tenth as wide. "It's curious that the first object we see from outside the solar system looks like that," said Loeb.
Its dark and reddened surface is also an indication of tholins, which are the result of organic molecules (like methane) being irradiated by cosmic rays for millions of years.
It was also determined to be rocky and metal rich, and to contain traces of tholins – organic molecules that have been irradiated by UV radiation.Also here [1] Archived 22 December 2017 at the Wayback Machine at Phys.org
No evidence of artificial signals emanating from the object so far detected by the Green Bank Telescope, but monitoring and analysis continue. Initial data are available for public inspection in the Breakthrough Listen archive
