New exoplanet found orbiting twin suns
space.com
space.com
Orbital period vs mass distribution of known exoplanets:
https://exoplanetarchive.ipac.caltech.edu/exoplanetplots/
As you can see there, the type of exoplanet humanity has detected the most are Jupiter-sized exoplanets orbiting close to their stars.
For two reasons:
High masses aid the radial velocity method because they make their host stars wobble more compared to lower mass exoplanets. Lower mass wobbles are just outside the sensitivity range of our best spectrometers.
Also aiding in the transit method, they have a short "year" - typically just a few days, making them pass in front of their star more often. The likelihood of detecting these is therefore a lot higher during a given observation time. In addition, exoplanets that orbit more distantly from their star have a lower chance of having an aligned orbital plane, that makes them transit the star through our line of sight to it. The necessary angle of alignment is much tighter compared to closer orbiting exoplanets.
Earth-like exoplanets (~0.003 Jupiter masses, period= ~365 days) are currently outside the sensitivity range of most instruments. Jupiter-like exoplanets tend to reduce the brightness of their host star by at most a few % when they occlude it - Earth has about a tenth of the diameter of Jupiter, so less than 1/100th of its disk area, so when an exoplanet like it passes in front of a star, it only reduces its brightness by a one hundredth of these few percent.
This is where even 16-bit cameras cease to be useful because even if the exposure times are optimized to be as close as possible to filling their "photon count buckets" in a single exposure, Earth and exoplanets like it would only reduce the brightness by 6 instead of 655 (of 2^16=65536) counts, which isn't that statistically meaningful anymore with all the additional uncertainty that is involved when taking images.
It may be that these are stars with smaller diameters, so the smaller planets occlude a larger fraction compared to sun-like stars.
Otherwise I suspect the required hardware is likely out of reach for amateurs with current technology.
Edit: Found these: https://en.wikipedia.org/wiki/MEarth_Project
> The MEarth Project is a United States NSF-funded, robotic observatory that is part of Fred Lawrence Whipple Observatory on Mt. Hopkins, Arizona, US. The project monitors the brightness of thousands of red dwarf stars with the goal of finding transiting planets. As red dwarf stars are small, any transiting planet blocks a larger proportion of starlight than transits around a Sun-like star would. This allows smaller planets to be detected through ground-based observations.
https://www.eso.org/public/teles-instr/paranal-observatory/s...
> The mission for SPECULOOS is to detect terrestrial planets as they transit across small, cool stars in the solar neighbourhood
It seems the terrestrial planets https://en.wikipedia.org/wiki/TRAPPIST detected are also around dwarf stars.
So I guess the summary is: finding and detecting earth-like planets around dwarf stars is possible, however around sun-like stars not quite yet using these two methods
Your point on period length stands. And anyway I'm just waxing lyrical, I'm a statistician and amateur stargazer not a pro :)
Sun-like is important in the search for life because despite putting out lots more energy, the suspicion is that yellow stars tend to be less temperamental in their flare behavior (so they don't scour the surface of any potential planets with large amounts of radiation every once in awhile). And there is evidence that our sun is even a particularly calm yellow star. The habitable zone is also in a region that doesn't tidally lock the planet; a day-night cycle seems important though not neccesarily a requirement for habitability. And yellow stars' lifecycle seems to be long enough to allow for life to form and evolve. Essentially they seem most likely to produce habitable planets - it's probably not mere happenstance that we live around one.
Even finding just one such planet will require a lot of observation:
The "geometric probability" of the orbital plane being aligned for an earth-like orbit seems to be around 0.5% [0]. Assuming every star has an earthlike planet [1], only 1 in 200 observed stars will be correctly aligned.
So observing 365*200=73,000 stars over an entire day (also not possible for ground-based telescopes due to the day/night cycle) should statistically result in one transit observation. The transit duration is also a problem, for an earth-like exoplanet it is 13 hours, so if the observation time is too short, one would only catch the beginning or end of the transit
[0] https://www.researchgate.net/figure/Transit-Properties-for-S...
[1] The current hypothesis seems to be that every star has at least one planet https://en.wikipedia.org/wiki/Planet-hosting_star), but it's all a bit up in the air as not many exoplanets (and especially earth-like ones) have been observed yet. The sample size is too low.
I think you mean, that stars have at least one planet on average. E.g. in the unlikely event that only one third of stars had planets, but each one of those stars had on average 3 stars, then it would fit the hypothesis of averaging at least one planet per star. It's not a stretch at all since our rather boring star has at least 8 planets, and of the 4,051 stars we can currently detect with exoplanets, they have a total of 5,438 planets, meaning over 1.34 planets per star not including the unknown but unquestionably vast number of planets we currently don't have the capability of detecting.
Still, just as we suspect large numbers of rogue planets that have lost their stars, there must be at least some stars out there that have lost their planets, whether to passing neutron stars or perhaps indigestion.
[0] https://en.wikipedia.org/wiki/Lists_of_exoplanets#:~:text=Th...
Unlike work charts though, I suspect they’re using FFT analysis to break down periodic signals.
Still, gas giants in one of those Goldilocks zone may have a lot of prime real estate.
> located about 46% of an AU from its stars
Does anyone find it weird that distances are quoted like this, and not 0.79AU and 0.46AU ?
Is this the conventional way to write it?
an equivalent monetary example would be describing something which costs 79 cents as costing "79% of a dollar"
sounds weird no?
LHC uses terms like 90% speed of light to be more specific example
i guess it all depends on what circles you do or do not float in.
And notations like 0.9c are also quite commonly used for velocities close to the speed of light
(the LHC tends to use TeV more often as a unit, which corresponds to a certain velocity for protons, but they mainly care about the energy)
But using percentages with the speed of light makes some sense because it marks one end of an absolute scale, there is no way to go 1.1c or 2.5c. So using a percentage emphasises how close we are to the maximum value.
But the same doesn't apply to AU.
half an AU, half the speed of light, half a parsec, half a mile, again fine
90% of an AU, 90% of the speed of light, 90% of a parsec, 90% of a mile. That sounds odd.
I could understand wanting to explain what AU stands for, and what an Astronomical Unit represents, it just seemed weird to then convert everything into percentages as well
nor does the average person know the exact radius/diameter of the earth, jupiter, or the sun, but we often see references to the earth is a fraction of jupiter and that the sun is some large number of jupiters.
Freedom Units are the best units.
I hear that Netflix is going to release a Three Body series this year, but it's going to be set in the U.S. which seems strange to me as the Chinese setting was an important part of the plot. Apparently Liu Cixin is on board with it, so I'm sure I'll give it a watch.
Edit: I thought Hewei Yu was great as Da Shi - very entertaining.
In short, you are far from alone - it's vastly overrated by one group and always advertised (more than ANY other book on here), and another group (including myself) thinks the characters are flat, the science is weak, and the overall "solution" in the book is far too contrived.
Let us not repeat the footgun of timezones and fixed periods for day tied to natural phenomena ever again.
Produce and distribute blackout curtains for sleep management.
EDIT: Note: due to time dilation, time should be measured locally only (I think?)
>It is estimated that approximately one third of the star systems in the Milky Way are binary or multiple, with the remaining two thirds being single stars.[62] The overall multiplicity frequency of ordinary stars is a monotonically increasing function of stellar mass. That is, the likelihood of being in a binary or a multi-star system steadily increases as the masses of the components increase.[61]
(later)
>While a number of binary star systems have been found to harbor extrasolar planets, such systems are comparatively rare compared to single star systems. Observations by the Kepler space telescope have shown that most single stars of the same type as the Sun have plenty of planets, but only one-third of binary stars do. According to theoretical simulations,[66] even widely separated binary stars often disrupt the discs of rocky grains from which protoplanets form.
I know that it's still going to be orbiting a center of mass somewhere between the two stars, but is that orbital ellipse significantly different from a planet orbiting one star?
And as the stars themselves are farther from the center of mass and relatively closer to the orbital ellipse, how does that change the behaviors at the equinox? It seems like there will be points on the long axis of the ellipse which are not the equinox but where one sun or another will be closer to the planet than at the equinox.
I don't see why this shouldn't hold for these sorts of discoveries ("BEBOP" in this case) - it's just a sort of weird namespace pollution for the language. Or perhaps I'm just an old curmudgeon.
If we ever, I don't know, make contact or send a mission to one of these planets, we can probably handle renaming it.
Additionally:
The newfound world is called BEBOP-1c, after the name of the project that collected the data, BEBOP, which stands for Binaries Escorted By Orbiting Planets. (BEBOP-1 is another name for the binary system TOI-1338.)We are unlikely to ever visit BEBOP. In short, it doesn't matter. But if we identified a very large impactor heading towards Earth, I suspect we might have a care in the naming instead of calling the asteroid something silly, such as "Butthead".[1]
[1] _ This is not intended to be a possible name for future very large impactors.
But the tradition from physics (and the closest areas, like astronomy) of using silly names does make it sound a lot like witchcraft. What is very funny for some people, and enraging for others.
I think it's because people don't know very much about astronomy but they want to sound smart so they pivot to an opinion on a subjective but related subject.
The systems are different in that Tatooine (as far as I remember) orbits around a pair of stars. Solaris is orbiting between the two stars in an orbit that should be highly unstable but for reasons unknown the planet appears to be stabilizing itself.
With the transit method (observing the planet passing in front of the host star(s) by seeing a temporary reduction in light: https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanet...), apparently yes, but not often and it is unclear when. The paper (https://arxiv.org/pdf/2301.10794.pdf) states:
> A visual inspection of TESS lightcurves shows no transit of TOI-1338/BEBOP-1c, however, thanks to orbital circulation, transits are expected to occur in due time. Circumbinary orbits exhibit nodal precession. This changes the orientation of a circumbinary planet’s orbital plane with respect to both the binary and the observer. This makes a planet change from a transiting to a non-transiting configuration (15, 30) as has been seen in a few systems (31, 32). Using an analytic criterion (33,34), we find that TOI-1338/BEBOP-1c is guaranteed to eventually transit mainly because the binary is so well-aligned with our line of sight (Ibin = 89.658◦) combined with the rather large size of the primary star (RA = 1.299R⊙). Whilst TOI-1338/BEBOP-1c will eventually transit, we are unable to predict when and how frequently. Its precession period is of order 119 years, during which time there will be two periods of transitability of a duration depending on TOI-1338/BEBOP-1c’s orbital inclination.
Tataounie is actually a nice place!
[1] https://files.littlebird.com.au/pb-Egew7Yw396-0rxbCp.png