I don't think the title is really accurate- it doesn't emit radio signals every 8 minutes, it emits constantly, but emits along an axis that periodically aligns with our viewing cone.
I don't know, we often talk about lighthouses "flashing", for example, when really they are constantly emitting but their rotation means the constant emission only periodically aligns with our viewing cone. This feels consistent with that.
There is an underlying tension in astronomical language. For over a thousand years "star" was a thing in the sky, a bit of light one could point a telescope at. We today understand stars not as lights but as giant objects billions of miles away. Which definition is used changes according to context. A steady beam that intermittently points towards earth can be described using either definition: It is a light in the sky that pulses, or it is aspherical star emitting a beam as it rotates. Both are correct.
I've never heard any astronomer I've worked with say that. What people said for a thousand years (incorrectly) is mostly irrelevant to modern science.
What I'm saying is that it's tecnically incorrect to say " emits radio signals every 8 minutes " because it emits constantly. Emission is different from detection.
Yes, it is incorrect and yes it is how language works. Even a "co-author on the paper" calls them "pulses" which maybe straddles the definition of periodic emission and detection.
Associate Professor Natasha Hurley-Walker, co-author on the paper, said that the pulses emitted by the white dwarf allowed the team to detect stellar flares on the Sun-like star, similar to those that create aurorae here on Earth.
I have heard that phrase from many. But Sirius is nowhere near the brightest star. Sirius is only brightest if one uses the "light in the night sky" definition of a star. Under the "ball of plasma" definition, Betelgeuse is far brighter than Sirius. Betelgeuse is visible to the eye and is many times brighter than Sirius... just not from our perspective of looking up at lights in the sky.
The brightness from our perspective might not be interesting to stellar astronomers, but to someone like a ship's navigator or NASA engineer building a satellite's navigation system, apparent brightness of a "star" is everything.
Your semantic argument is comparing apples and oranges, and therefore fails. The semantics of the word "emit" are not like the semantics of "brightest in the night sky." The first describes an objective action, while the second describes a subjective detection. You sneakily drop the "in the night sky" to try to turn a subjective statement into an objective one, but this is deception.
I have taken enough stellar astronomy undergrads to understand that "star" is a nuanced term, that "Which is brightest?" is a loaded question on an exam. Read any astronomical journal and you will see splits between the physics/math types who discuss stars as balls of gas, and the observer/telescope types who talk of them as lights to be seen. And anyone reading history can witness how often the definition of "star" has changed over time, and continues to change to this day.
People also said the earth was flat for thousands of years. Stop intentionally conflating incorrect casual vernacular with actual scientific language. You are, quite simply, plain wrong.
"Pulsar" = Scientific term. They do not pulse, except from our perspective (the light-in-the-sky definition). Pulsars have kept the name and are regularly described as pulsing objects when discussed the context of observations. Want to build a telescope to study pulsars? Then you will plan for them being pulsing dots of light.
"Neutron Star" = Scientific term. But is not a star by accepted scientific definition. (Also "Quark Stars", which remain mostly mathematical but are still not stars.)
Science is full of ancient terminology. Being imperfect or having more than one meaning does not make a term "casual vernacular".
Should every phenomenon be renamed as soon as our knowledge of it depens? Or should we wait until we have reached an understanding of the thing in itself until we dare name a phenomenon? Both of these are obviously impractical, useless and harmful options for science and society at large.
Take a look also at quasars, which are supermassive black holes at the center of galaxies, fed by enormous amounts of matter falling into the gravity well.
If this thing has been sending repeating signals for what I presume to be a very long time, shouldn't we have already detected it? Or is it that we've always been able to detect this particular signal, but have only just now traced it to its source?
Sounds like the OnOff star from A Deepness in the Sky by Vernor Vinge. It started with very quick oscillation and eventually settled toward 200 years off, 60 years on (or so). Interesting speculation about what this would do to a developing species/society.
Unfortunately the headline is misleading. It's constantly emitting radio signals, it's just spinning in a way that points at us every 8 minutes. Great book though!
Yes but repeated evenly spaced pulses are special and limited to a special subset of stars caller pulsars. The sun is mostly wideband radio noise where the article is talking about distinct regular pulses which are rarer.
If you have satellite TV you already have a solar radiotelescope.
Measure the voltage on the AGC line in the tuner and you'll see a peak as the sun passes the azimuth of the dish. That's it picking up 10GHz solar radiation, and turning its gain down to compensate for the background noise.
I didn't know that there was a whole slew of these red and white dwarfs orbiting other stars, which I think must make it extra unlikely for there to be habitable planets in the same system, the process of one star capturing another is going to realy wreck havock with any original planets,
and any surviving lifeform to get past the am radio phase of technological development
thats! GPM J071507−114153, "the pulse on your dial" brought to by astrophyisal phenominon, every 8 min, for eterinty
The same general reasons that allow planets to form instead of all the mass going into a single star: mass/momentum/charge asymmetries in the original stellar nebula, complex interactions in the accretion disk, gravitational perturbations from other stars in the same stellar nursery, etc
What I'm saying is that it's tecnically incorrect to say " emits radio signals every 8 minutes " because it emits constantly. Emission is different from detection.
I have heard that phrase from many. But Sirius is nowhere near the brightest star. Sirius is only brightest if one uses the "light in the night sky" definition of a star. Under the "ball of plasma" definition, Betelgeuse is far brighter than Sirius. Betelgeuse is visible to the eye and is many times brighter than Sirius... just not from our perspective of looking up at lights in the sky.
The brightness from our perspective might not be interesting to stellar astronomers, but to someone like a ship's navigator or NASA engineer building a satellite's navigation system, apparent brightness of a "star" is everything.
Why yes, I am a linguist.
I have taken enough stellar astronomy undergrads to understand that "star" is a nuanced term, that "Which is brightest?" is a loaded question on an exam. Read any astronomical journal and you will see splits between the physics/math types who discuss stars as balls of gas, and the observer/telescope types who talk of them as lights to be seen. And anyone reading history can witness how often the definition of "star" has changed over time, and continues to change to this day.
"Neutron Star" = Scientific term. But is not a star by accepted scientific definition. (Also "Quark Stars", which remain mostly mathematical but are still not stars.)
Science is full of ancient terminology. Being imperfect or having more than one meaning does not make a term "casual vernacular".
Should every phenomenon be renamed as soon as our knowledge of it depens? Or should we wait until we have reached an understanding of the thing in itself until we dare name a phenomenon? Both of these are obviously impractical, useless and harmful options for science and society at large.
"Well it's probably a whole hippo, it's just the rest of him is under the water."
What wait, 8mn is a long period?
I checked the fastest pulsar observed rotates and “emits” at 716Hz! :shock:
That’s ~70.000km/s on the equator given its ~30km diameter :shock: :shock:
https://en.wikipedia.org/wiki/PSR_J1748%E2%88%922446ad
Wasn't there a subreddit dedicated to terrifying two or so sentences stories?
https://en.wikipedia.org/wiki/Black_hole_bomb
Make it random, at least receivers would have a harder time identifying intentions
And I still find it mindboggling that the radio pulses from the star that we're receiving were emitted 5000 years ago.
Seriously, if data doesn't fit the classical definition, you need to update the classical definition.
https://en.wikipedia.org/wiki/Solar_radio_emission
https://en.wikipedia.org/wiki/Radio_telescope
https://en.wikipedia.org/wiki/Pulsar
Measure the voltage on the AGC line in the tuner and you'll see a peak as the sun passes the azimuth of the dish. That's it picking up 10GHz solar radiation, and turning its gain down to compensate for the background noise.
thats! GPM J071507−114153, "the pulse on your dial" brought to by astrophyisal phenominon, every 8 min, for eterinty
Objects with a period this long are much rarer, according to this wp article there are only 12 we know of. I thought it was fewer!
https://en.wikipedia.org/wiki/Long_period_radio_transient