Where is the intervening light in the M87 black hole? Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern) What stellar content do we want to share with Twitter?Statistically, what would the average distance of the closest black hole be?How can black holes be sometimes so gaseous?How did the object CO-0.40-0.22 get its name, and how is it distinct from CO-0.40-0.22*?What will happen to the shape of a galaxy when a super massive black hole lying in its center dies(evaporates out)?How did the authors determine both the spatial size of gas cloud HCN-0.009-0.044 and its central mass at the same time?Why does the author believe that the central mass that gas cloud HCN-0.009-0.044 orbits is smaller than our solar system?Is this the best non-radio image of whatever's at the center of M87? How was it taken?Why isn't the relativistic jet visible in the image of the M87 black hole?Why is the ring of light around the M87 black hole bigger than the photon sphere?
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Where is the intervening light in the M87 black hole?
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)
What stellar content do we want to share with Twitter?Statistically, what would the average distance of the closest black hole be?How can black holes be sometimes so gaseous?How did the object CO-0.40-0.22 get its name, and how is it distinct from CO-0.40-0.22*?What will happen to the shape of a galaxy when a super massive black hole lying in its center dies(evaporates out)?How did the authors determine both the spatial size of gas cloud HCN-0.009-0.044 and its central mass at the same time?Why does the author believe that the central mass that gas cloud HCN-0.009-0.044 orbits is smaller than our solar system?Is this the best non-radio image of whatever's at the center of M87? How was it taken?Why isn't the relativistic jet visible in the image of the M87 black hole?Why is the ring of light around the M87 black hole bigger than the photon sphere?
$begingroup$
The M87 black hole is at the centre, more or less, of an elliptical galaxy of 1 trillion or more stars. So certainly there are stars and other light emitting objects (emission nebula e.g.) in the intervening 53 million light years between earth and the black hole.
How is it that the centre of the black hole image is perfectly dark, as if it is being observed directly, with not one point of light between the black hole and earth? I appreciate that space is mostly empty, but do we really have an unobscured line of sight to a black hole in the centre of an enormous elliptical galaxy?
Does it have something to do with the type of light being observed?
black-hole m87
edited Apr 14 at 20:02
Peter Mortensen
1556
asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
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Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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$endgroup$
add a comment |
$begingroup$
The M87 black hole is at the centre, more or less, of an elliptical galaxy of 1 trillion or more stars. So certainly there are stars and other light emitting objects (emission nebula e.g.) in the intervening 53 million light years between earth and the black hole.
How is it that the centre of the black hole image is perfectly dark, as if it is being observed directly, with not one point of light between the black hole and earth? I appreciate that space is mostly empty, but do we really have an unobscured line of sight to a black hole in the centre of an enormous elliptical galaxy?
Does it have something to do with the type of light being observed?
black-hole m87
edited Apr 14 at 20:02
Peter Mortensen
1556
asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
I think it's mostly that the field of view is incredibly tiny. The popular published image seems to be about four times the diameter of the central dark region, so representing about 800 billion km at the distance of M87 or about 0.1 light year. At the distance of the edge of our galaxy, it would represent about 1/1000 of that. There simply isn't anything in that very very narrow cone bright enough to show up.
$endgroup$
– Steve Linton
Apr 14 at 10:43
1
$begingroup$
Also, the observations are made in radio, where intervening gas and dust hardly absorbs anything.
$endgroup$
– pela
Apr 14 at 10:47
$begingroup$
It isn't perfectly dark.
$endgroup$
– Rob Jeffries
Apr 14 at 21:35
add a comment |
$begingroup$
The M87 black hole is at the centre, more or less, of an elliptical galaxy of 1 trillion or more stars. So certainly there are stars and other light emitting objects (emission nebula e.g.) in the intervening 53 million light years between earth and the black hole.
How is it that the centre of the black hole image is perfectly dark, as if it is being observed directly, with not one point of light between the black hole and earth? I appreciate that space is mostly empty, but do we really have an unobscured line of sight to a black hole in the centre of an enormous elliptical galaxy?
Does it have something to do with the type of light being observed?
black-hole m87
edited Apr 14 at 20:02
Peter Mortensen
1556
asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
The M87 black hole is at the centre, more or less, of an elliptical galaxy of 1 trillion or more stars. So certainly there are stars and other light emitting objects (emission nebula e.g.) in the intervening 53 million light years between earth and the black hole.
How is it that the centre of the black hole image is perfectly dark, as if it is being observed directly, with not one point of light between the black hole and earth? I appreciate that space is mostly empty, but do we really have an unobscured line of sight to a black hole in the centre of an enormous elliptical galaxy?
Does it have something to do with the type of light being observed?
black-hole m87
black-hole m87
edited Apr 14 at 20:02
Peter Mortensen
1556
asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited Apr 14 at 20:02
Peter Mortensen
1556
asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited Apr 14 at 20:02
Peter Mortensen
1556
edited Apr 14 at 20:02
Peter Mortensen
1556
edited Apr 14 at 20:02
Peter Mortensen
1556
1556
asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
asked Apr 14 at 10:33
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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$begingroup$
I think it's mostly that the field of view is incredibly tiny. The popular published image seems to be about four times the diameter of the central dark region, so representing about 800 billion km at the distance of M87 or about 0.1 light year. At the distance of the edge of our galaxy, it would represent about 1/1000 of that. There simply isn't anything in that very very narrow cone bright enough to show up.
$endgroup$
– Steve Linton
Apr 14 at 10:43
1
$begingroup$
Also, the observations are made in radio, where intervening gas and dust hardly absorbs anything.
$endgroup$
– pela
Apr 14 at 10:47
$begingroup$
It isn't perfectly dark.
$endgroup$
– Rob Jeffries
Apr 14 at 21:35
add a comment |
$begingroup$
I think it's mostly that the field of view is incredibly tiny. The popular published image seems to be about four times the diameter of the central dark region, so representing about 800 billion km at the distance of M87 or about 0.1 light year. At the distance of the edge of our galaxy, it would represent about 1/1000 of that. There simply isn't anything in that very very narrow cone bright enough to show up.
$endgroup$
– Steve Linton
Apr 14 at 10:43
1
$begingroup$
Also, the observations are made in radio, where intervening gas and dust hardly absorbs anything.
$endgroup$
– pela
Apr 14 at 10:47
$begingroup$
It isn't perfectly dark.
$endgroup$
– Rob Jeffries
Apr 14 at 21:35
$begingroup$
I think it's mostly that the field of view is incredibly tiny. The popular published image seems to be about four times the diameter of the central dark region, so representing about 800 billion km at the distance of M87 or about 0.1 light year. At the distance of the edge of our galaxy, it would represent about 1/1000 of that. There simply isn't anything in that very very narrow cone bright enough to show up.
$endgroup$
– Steve Linton
Apr 14 at 10:43
$begingroup$
I think it's mostly that the field of view is incredibly tiny. The popular published image seems to be about four times the diameter of the central dark region, so representing about 800 billion km at the distance of M87 or about 0.1 light year. At the distance of the edge of our galaxy, it would represent about 1/1000 of that. There simply isn't anything in that very very narrow cone bright enough to show up.
$endgroup$
– Steve Linton
Apr 14 at 10:43
1
1
$begingroup$
Also, the observations are made in radio, where intervening gas and dust hardly absorbs anything.
$endgroup$
– pela
Apr 14 at 10:47
$begingroup$
Also, the observations are made in radio, where intervening gas and dust hardly absorbs anything.
$endgroup$
– pela
Apr 14 at 10:47
$begingroup$
It isn't perfectly dark.
$endgroup$
– Rob Jeffries
Apr 14 at 21:35
$begingroup$
It isn't perfectly dark.
$endgroup$
– Rob Jeffries
Apr 14 at 21:35
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Based on the comment from @SteveLinton
The radius of M87 is given to be 60,000 light years, which is a volume of 900 trillion cubic light years. Given that it contains roughly one trillion stars, there is an average of 900 cubic light years for each star.
Several resources referred to the diameter of the black hole in the range of 1.5 light days (38 billion km). That's 0.004 light years.
If you consider the cylinder1 extending from the black hole to the edge of M87, the cylinder is 0.004 light years in diameter with a height of 60,000 light years. The volume of that cylinder is just over 3 cubic light years. Since there is one star for every 900 cubic light years, it follows that the cylinder encompassing our line of sight between the black hole and the edge of M87 is empty of any stars.
Whether or not any star would even be bright enough to be visible is another matter.
1Technically a conic frustum but I don't think the difference in volume is significant.
answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
"The radius of M87 is given to be 60,000 light years.". No, more like 32 - 50 kiloparsecs radius = 100,000 - 160,000 light years radius. E.g. "According to Stoyan et al. (2010), the distance of M87 is 54.9 million light years and its diameter is 132,000 light years." and "Diameter: 120,000 ly".
$endgroup$
– Peter Mortensen
Apr 14 at 19:15
$begingroup$
Doesn't this answer assume that the galaxy is of uniform density?
$endgroup$
– JBentley
Apr 14 at 19:27
1
$begingroup$
@PeterMortensen I'm not sure I understand. Your sources cite a diameter of 120,000 LY and 132,000 LY. I'm using a radius of 60,000 LY. Radius = 1/2 Diameter.
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:12
$begingroup$
@JBentley Yes and I appreciate this is a fallacy (Olbers' Paradox).
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:15
add a comment |
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$begingroup$
Based on the comment from @SteveLinton
The radius of M87 is given to be 60,000 light years, which is a volume of 900 trillion cubic light years. Given that it contains roughly one trillion stars, there is an average of 900 cubic light years for each star.
Several resources referred to the diameter of the black hole in the range of 1.5 light days (38 billion km). That's 0.004 light years.
If you consider the cylinder1 extending from the black hole to the edge of M87, the cylinder is 0.004 light years in diameter with a height of 60,000 light years. The volume of that cylinder is just over 3 cubic light years. Since there is one star for every 900 cubic light years, it follows that the cylinder encompassing our line of sight between the black hole and the edge of M87 is empty of any stars.
Whether or not any star would even be bright enough to be visible is another matter.
1Technically a conic frustum but I don't think the difference in volume is significant.
answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
"The radius of M87 is given to be 60,000 light years.". No, more like 32 - 50 kiloparsecs radius = 100,000 - 160,000 light years radius. E.g. "According to Stoyan et al. (2010), the distance of M87 is 54.9 million light years and its diameter is 132,000 light years." and "Diameter: 120,000 ly".
$endgroup$
– Peter Mortensen
Apr 14 at 19:15
$begingroup$
Doesn't this answer assume that the galaxy is of uniform density?
$endgroup$
– JBentley
Apr 14 at 19:27
1
$begingroup$
@PeterMortensen I'm not sure I understand. Your sources cite a diameter of 120,000 LY and 132,000 LY. I'm using a radius of 60,000 LY. Radius = 1/2 Diameter.
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:12
$begingroup$
@JBentley Yes and I appreciate this is a fallacy (Olbers' Paradox).
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:15
add a comment |
$begingroup$
Based on the comment from @SteveLinton
The radius of M87 is given to be 60,000 light years, which is a volume of 900 trillion cubic light years. Given that it contains roughly one trillion stars, there is an average of 900 cubic light years for each star.
Several resources referred to the diameter of the black hole in the range of 1.5 light days (38 billion km). That's 0.004 light years.
If you consider the cylinder1 extending from the black hole to the edge of M87, the cylinder is 0.004 light years in diameter with a height of 60,000 light years. The volume of that cylinder is just over 3 cubic light years. Since there is one star for every 900 cubic light years, it follows that the cylinder encompassing our line of sight between the black hole and the edge of M87 is empty of any stars.
Whether or not any star would even be bright enough to be visible is another matter.
1Technically a conic frustum but I don't think the difference in volume is significant.
answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
"The radius of M87 is given to be 60,000 light years.". No, more like 32 - 50 kiloparsecs radius = 100,000 - 160,000 light years radius. E.g. "According to Stoyan et al. (2010), the distance of M87 is 54.9 million light years and its diameter is 132,000 light years." and "Diameter: 120,000 ly".
$endgroup$
– Peter Mortensen
Apr 14 at 19:15
$begingroup$
Doesn't this answer assume that the galaxy is of uniform density?
$endgroup$
– JBentley
Apr 14 at 19:27
1
$begingroup$
@PeterMortensen I'm not sure I understand. Your sources cite a diameter of 120,000 LY and 132,000 LY. I'm using a radius of 60,000 LY. Radius = 1/2 Diameter.
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:12
$begingroup$
@JBentley Yes and I appreciate this is a fallacy (Olbers' Paradox).
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:15
add a comment |
$begingroup$
Based on the comment from @SteveLinton
The radius of M87 is given to be 60,000 light years, which is a volume of 900 trillion cubic light years. Given that it contains roughly one trillion stars, there is an average of 900 cubic light years for each star.
Several resources referred to the diameter of the black hole in the range of 1.5 light days (38 billion km). That's 0.004 light years.
If you consider the cylinder1 extending from the black hole to the edge of M87, the cylinder is 0.004 light years in diameter with a height of 60,000 light years. The volume of that cylinder is just over 3 cubic light years. Since there is one star for every 900 cubic light years, it follows that the cylinder encompassing our line of sight between the black hole and the edge of M87 is empty of any stars.
Whether or not any star would even be bright enough to be visible is another matter.
1Technically a conic frustum but I don't think the difference in volume is significant.
answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
Based on the comment from @SteveLinton
The radius of M87 is given to be 60,000 light years, which is a volume of 900 trillion cubic light years. Given that it contains roughly one trillion stars, there is an average of 900 cubic light years for each star.
Several resources referred to the diameter of the black hole in the range of 1.5 light days (38 billion km). That's 0.004 light years.
If you consider the cylinder1 extending from the black hole to the edge of M87, the cylinder is 0.004 light years in diameter with a height of 60,000 light years. The volume of that cylinder is just over 3 cubic light years. Since there is one star for every 900 cubic light years, it follows that the cylinder encompassing our line of sight between the black hole and the edge of M87 is empty of any stars.
Whether or not any star would even be bright enough to be visible is another matter.
1Technically a conic frustum but I don't think the difference in volume is significant.
answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited Apr 14 at 11:37
answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
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answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
answered Apr 14 at 11:29
Bumptious Q BangwhistleBumptious Q Bangwhistle
1965
1965
New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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New contributor
Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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Bumptious Q Bangwhistle is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$begingroup$
"The radius of M87 is given to be 60,000 light years.". No, more like 32 - 50 kiloparsecs radius = 100,000 - 160,000 light years radius. E.g. "According to Stoyan et al. (2010), the distance of M87 is 54.9 million light years and its diameter is 132,000 light years." and "Diameter: 120,000 ly".
$endgroup$
– Peter Mortensen
Apr 14 at 19:15
$begingroup$
Doesn't this answer assume that the galaxy is of uniform density?
$endgroup$
– JBentley
Apr 14 at 19:27
1
$begingroup$
@PeterMortensen I'm not sure I understand. Your sources cite a diameter of 120,000 LY and 132,000 LY. I'm using a radius of 60,000 LY. Radius = 1/2 Diameter.
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:12
$begingroup$
@JBentley Yes and I appreciate this is a fallacy (Olbers' Paradox).
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:15
add a comment |
$begingroup$
"The radius of M87 is given to be 60,000 light years.". No, more like 32 - 50 kiloparsecs radius = 100,000 - 160,000 light years radius. E.g. "According to Stoyan et al. (2010), the distance of M87 is 54.9 million light years and its diameter is 132,000 light years." and "Diameter: 120,000 ly".
$endgroup$
– Peter Mortensen
Apr 14 at 19:15
$begingroup$
Doesn't this answer assume that the galaxy is of uniform density?
$endgroup$
– JBentley
Apr 14 at 19:27
1
$begingroup$
@PeterMortensen I'm not sure I understand. Your sources cite a diameter of 120,000 LY and 132,000 LY. I'm using a radius of 60,000 LY. Radius = 1/2 Diameter.
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:12
$begingroup$
@JBentley Yes and I appreciate this is a fallacy (Olbers' Paradox).
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:15
$begingroup$
"The radius of M87 is given to be 60,000 light years.". No, more like 32 - 50 kiloparsecs radius = 100,000 - 160,000 light years radius. E.g. "According to Stoyan et al. (2010), the distance of M87 is 54.9 million light years and its diameter is 132,000 light years." and "Diameter: 120,000 ly".
$endgroup$
– Peter Mortensen
Apr 14 at 19:15
$begingroup$
"The radius of M87 is given to be 60,000 light years.". No, more like 32 - 50 kiloparsecs radius = 100,000 - 160,000 light years radius. E.g. "According to Stoyan et al. (2010), the distance of M87 is 54.9 million light years and its diameter is 132,000 light years." and "Diameter: 120,000 ly".
$endgroup$
– Peter Mortensen
Apr 14 at 19:15
$begingroup$
Doesn't this answer assume that the galaxy is of uniform density?
$endgroup$
– JBentley
Apr 14 at 19:27
$begingroup$
Doesn't this answer assume that the galaxy is of uniform density?
$endgroup$
– JBentley
Apr 14 at 19:27
1
1
$begingroup$
@PeterMortensen I'm not sure I understand. Your sources cite a diameter of 120,000 LY and 132,000 LY. I'm using a radius of 60,000 LY. Radius = 1/2 Diameter.
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:12
$begingroup$
@PeterMortensen I'm not sure I understand. Your sources cite a diameter of 120,000 LY and 132,000 LY. I'm using a radius of 60,000 LY. Radius = 1/2 Diameter.
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:12
$begingroup$
@JBentley Yes and I appreciate this is a fallacy (Olbers' Paradox).
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:15
$begingroup$
@JBentley Yes and I appreciate this is a fallacy (Olbers' Paradox).
$endgroup$
– Bumptious Q Bangwhistle
Apr 14 at 21:15
add a comment |
Bumptious Q Bangwhistle is a new contributor. Be nice, and check out our Code of Conduct.
Bumptious Q Bangwhistle is a new contributor. Be nice, and check out our Code of Conduct.
Bumptious Q Bangwhistle is a new contributor. Be nice, and check out our Code of Conduct.
Bumptious Q Bangwhistle is a new contributor. Be nice, and check out our Code of Conduct.
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$begingroup$
I think it's mostly that the field of view is incredibly tiny. The popular published image seems to be about four times the diameter of the central dark region, so representing about 800 billion km at the distance of M87 or about 0.1 light year. At the distance of the edge of our galaxy, it would represent about 1/1000 of that. There simply isn't anything in that very very narrow cone bright enough to show up.
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– Steve Linton
Apr 14 at 10:43
1
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Also, the observations are made in radio, where intervening gas and dust hardly absorbs anything.
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– pela
Apr 14 at 10:47
$begingroup$
It isn't perfectly dark.
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– Rob Jeffries
Apr 14 at 21:35