DBT
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Gah, typo, tiny phone screen, I don't know where the 'astronomists' came from.
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Stars go missing.
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barbos
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Hubble telescope can see individual stars in Andromeda Galaxy just fine, not all of them of course.
it just have to be bright enough and outside of the central core where there is too much background light and gas. But I suspect in infrared it can see into the core of Andromeda as well
In fact Hubble himself (Astronomer, not the telescope) is famous because he was the first who saw an individual star in Andromeda. Well, he realized that Andromeda is another Galaxy, hence the stars in it are far away.
it just have to be bright enough and outside of the central core where there is too much background light and gas. But I suspect in infrared it can see into the core of Andromeda as well
In fact Hubble himself (Astronomer, not the telescope) is famous because he was the first who saw an individual star in Andromeda. Well, he realized that Andromeda is another Galaxy, hence the stars in it are far away.
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Bomb#20
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It wouldn't though. You're proposing, equivalently, that the rock is casting a shadow in the star's light and we're in the shadow. But a rock can't be much bigger than Jupiter, or else it would be a star itself and we'd see it. That means its shadow is no more than about a hundred thousand miles wide. The Earth is moving around the sun at about 18 miles a second, so it will typically pop out of any shadow within an hour and a half. Even if the rock is coincidentally moving at the same speed and direction as the Earth, the Earth is in an orbit -- its direction becomes significantly different in a matter of days. The rock is in a completely different orbit so it can't track the Earth's changes in direction. Back of the envelope, it's impossible for us to stay in anything's shadow longer than a week.
Ok, I get what you are saying... but parallax... the tiny "wobble" of Earth as it goes from one side of our star to the other, seems to me to be an insignificant change in perspective of something so very far away... I guess we could just do the trig and see how big an object would have to be to still be "in the way" of a point viewed from many light years away.
Jimmy Higgins
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...and we can let the astronomers (or astronomists
) do that type of thinking. If astronomers say 'we have no idea where a few hundred stars went', I'm thinking they have already gone through a long list of reasons why they aren't visible and some easy explanation isn't available.Bomb#20
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Well, the argument as written doesn't depend on any of that -- all that matters is that there's an upper limit on rock size, and the Earth's orbit is a lot bigger than any rock we're hypothesizing might be in the way. But what the argument does depend on is the assumption that the rock isn't any bigger than the light source it's blocking. That's of course the case for any normal star -- anything from a red dwarf to a red giant, and I assumed that was what was being blocked -- if the rock is "so very far away" then it can't block the star, any more than Venus can block the sun as viewed from Earth. All you get in that case is a transit, not an occultation.
But if the star that went missing was effectively a point source -- i.e., a white dwarf or a neutron star -- then the argument doesn't go through and we'd have to sweat the trig as you say.
^^^ This ^^^. My first reaction when I saw the story was "In 1950 astronomy was done with photographic film. The missing stars never existed, just tiny manufacturing defects in the film.". But on second thought I figured the astronomers probably thought of that......and we can let the astronomers (or astronomists
hurtinbuckaroo
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DBT
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Tiny manufacturing defects in the film should be easy enough to detect and eliminate. So should dark objects that may be eclipsing a star, seeing the relative positions of the star, the dark object and the earth are not fixed.
Here's a more thorough article;
''The large number of images we are dealing with within the complete VASCO project and the increased complexity of our searches requires a better approach than was done in the pilot study. done in the pilot study.
Clearly, we must explore ways to transfer avail ourselves of automatized procedures as much as possible, but without relying on algorithms for all candidate selection and quality control. At this moment, such algorithms are still being developed. Current problems are related to the inefficiency of comparing two images manually, comparing images based on CCD cam-eras with images from old photographic plates, and finally we must adjust the algorithms to identify the most meaningful candidates.
In a separate paper by Pelck-mans et al. (in prep.) we propose a new tool for handling a large number of images using methods of machine learning.5.4.Summary VASCO is a project that provides an opportunity to discover many past transients events, both objects that vanish and those that appear. The time span between these surveys is large.
This allows for other phenomena to be discovered other than what can be expected in on-going transient surveys like e.g. ZTF. Using a large cross-match radius of 30 arcseconds, we obtained a sample of150,000 USNO objects that cannot to be found in Pan-STARRS. This represents an interesting starting sample in searches for vanishing objects.
As we used a large cross-match radius of 30 arcsec (instead of the more typ-ical 3 to 5 arcsec radius), we underestimate the real number of potential mismatches that can be found through cross-matching attempts. We have investigated the statistical properties of this sample and found that many of these “mismatches” are occurring in the red band.Visual checks confirm that indeed the most interesting cases, about 100, are mostly one time detections in the red band. At present, we do not know what these detections represent. We believe they may be a mixed bag of transient phenomena.
The object found by Villarroel etal. (2016) is of the same class, and might possibly be a variable object that dropped 4.5 mag since it was imaged long ago. It could also have been some type of transient event such as a background high-redshift supernova or a flaring M dwarf.''
Here's a more thorough article;
''The large number of images we are dealing with within the complete VASCO project and the increased complexity of our searches requires a better approach than was done in the pilot study. done in the pilot study.
Clearly, we must explore ways to transfer avail ourselves of automatized procedures as much as possible, but without relying on algorithms for all candidate selection and quality control. At this moment, such algorithms are still being developed. Current problems are related to the inefficiency of comparing two images manually, comparing images based on CCD cam-eras with images from old photographic plates, and finally we must adjust the algorithms to identify the most meaningful candidates.
In a separate paper by Pelck-mans et al. (in prep.) we propose a new tool for handling a large number of images using methods of machine learning.5.4.Summary VASCO is a project that provides an opportunity to discover many past transients events, both objects that vanish and those that appear. The time span between these surveys is large.
This allows for other phenomena to be discovered other than what can be expected in on-going transient surveys like e.g. ZTF. Using a large cross-match radius of 30 arcseconds, we obtained a sample of150,000 USNO objects that cannot to be found in Pan-STARRS. This represents an interesting starting sample in searches for vanishing objects.
As we used a large cross-match radius of 30 arcsec (instead of the more typ-ical 3 to 5 arcsec radius), we underestimate the real number of potential mismatches that can be found through cross-matching attempts. We have investigated the statistical properties of this sample and found that many of these “mismatches” are occurring in the red band.Visual checks confirm that indeed the most interesting cases, about 100, are mostly one time detections in the red band. At present, we do not know what these detections represent. We believe they may be a mixed bag of transient phenomena.
The object found by Villarroel etal. (2016) is of the same class, and might possibly be a variable object that dropped 4.5 mag since it was imaged long ago. It could also have been some type of transient event such as a background high-redshift supernova or a flaring M dwarf.''
This article clarifies that the researchers identified the "missing stars" as being obstructed by "transient events". So.. basically exactly what I had been saying.
Small children learn object permanence at a young age (when they realize a hidden thing has not ceased to exist). The pop science article must have been written by kids that still find a game of peek-a-boo fascinating entertainment.
Small children learn object permanence at a young age (when they realize a hidden thing has not ceased to exist). The pop science article must have been written by kids that still find a game of peek-a-boo fascinating entertainment.
DBT
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Some stars may be eclipsed for a period of time. That is not the case with all of the missing stars.
steve_bank
Diabetic retinopathy and poor eyesight. Typos ...
Is it illegal to falsely report missing stars? Think of all the wasted resources and money spent looking for them.
DBT
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Not to mention appearing extremely incompetent if it is a simple case of dark object eclipse and the star reappears a short time after reported missing.
Well, it's a learning opportunity, at least... unless, of course, we just resign ourselves to always appeal to authority.. "someone else prolly thought of that... I'm going back to bed".
sometimes, people think of things, and then fail to report those things because it sells better to make the situation more mysterious sounding.
Jimmy Higgins
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Alarmist blog post about poorly understood and poorly researched article about competent and reserved published paper.