# Tag Info

## Hot answers tagged trans-neptunian-object

13

Well yes, because Brown & Batygin (2021) say the perihelion would be $300^{+85}_{-60}$ au, so there is roughly a 50% chance that the perihelion is smaller than 300 au according to their work. The quoted error bars represent their estimate of the 16th to 84th percentiles of a probability distribution, so conceivably the perihelion could even be a little ...

11

Yes/No as needed. The MPC, which is fairly authoritative, lists only (134340) Pluto, and doesn't include Charon and the other satellites of Pluto. Formally, binary asteroids are given a single classification, so 2000 CF105 only has a single code, despite being formed of two pieces of ice and rock. In other contexts it might be convenient to include it. It ...

10

Light flux decreases as one over distance squared. So if Eris is 100 times further away from the Sun than the Earth is, then the amount of light that reaches Eris is 10 000 less than that on Earth. Since a difference of five magnitudes is a factor of 100, The Sun would have an apparent magnitude -16.7 seen from Eris' aphelion, as opposed to -26.7 magnitude ...

9

You are correct that the IAU definition of "clearing the orbit" has the problem of being not explicitly quantified. And a complete clearing was obviously never the intention behind the definition. I like this statement by Steven Soter: The IAU definition of a planet as a heliocentric body that "has cleared the neighborhood around its orbit” is problematic....

6

From the observer's point of view 1 million km away, the TNO's apparent angular motion is $$\mathrm{\frac{8~m/s}{10^9~m} = 8 \times 10^{-9}~rad/s = 0.00165~^\circ/h}.$$ Assuming that the observer at 18 billion km = 120 au is in a circular orbit around the Sun, the orbital period is 1203/2 = 1320 years, making the Sun appear to move the other way at \...

5

I'll use the TESS satellite as an example, which you might use to look at transiting exoplanets for example. Go to https://heasarc.gsfc.nasa.gov/docs/tess/data-access.html this gives you a list of links to other useful TESS websites, data access and analysis tools. There are links here to get raw and processed light curves or even to get light curves for ...

4

Black holes are black. They are only observed directly by telescopes if they are accreting matter. Any radiation observed comes from the matter surrounding the black hole. Generally speaking, the smaller the black hole, the hotter the accreted material becomes. For something of planetary mass, one might expect X-rays and Gamma rays from accreting material. ...

4

The International Astronomical Union describes this minor planet naming process: Minor Planet Center assigns provisional designation MPC assigns permanent designation Discoverer suggests name IAU working group reviews name MPC publishes name Accepted names become official when they are published, along with their accompanying citations, in the Minor ...

2

Has the rotation of Eris and Dysnomia been observed? is it possible to shoot multiple images of them to see how they rotate around each other? Has this been attempted? Yes! Yes! and Yes! From the 2020 preprint The Eris/Dysnomia system I: The orbit of Dysnomia found in Wikipedia's Dysnomia (moon) see the following Hubble Space Telescope Wide Field Camera 3 ...

2

Dark Energy Survey data have yielded several TNO discoveries. Bernardinelli et al. 2020 describe their method in detail. First they compute a trial orbit from images where a transient object was detected. Then Final validation of the reality of linked orbits uses a new "sub-threshold confirmation" test, wherein we demand the object be detectable ...

1

Queries to the JPL Small Body Database or the ESA Asteroids Dynamic Site for such bodies return several results. Some of the bigger ones are: Centaurs with H < 10 and i < 4° 386968 (2012 BR61), q = 11.7 au, Q = 31.6 au 527328 (2007 TK422), q = 17.0 au, Q = 25.2 au TNOs with H < 5 and i < 2° 119951 (2002 KX14), q = 37.3 au, Q = 40.9 au 42301 (...

1

Maybe, Harvard scientists have proposed a way to determine, once and for all, whether Planet Nine actually could be a black hole. Specifically, the new method would scour the outer solar system for evidence of telltale flares that are emitted when a black hole devours a comet or other distant object. Such flares, they say, should be detectable by the ...

1

Heliopause is believed to be at a distance of about 123 AU away from the Sun. Now, if you look at the list of farthest body in the solar system, you will see two bodies located approximately at that distance: 2018 VG18 and predicted FarFarOut (124.12 AU and ~140 AU from the sun as of June 2020 respectively). They are considered the farthest TNOs in the solar ...

1

It's parallax. An object this far from the Sun is essentially "stationary" compared with how fast the Earth goes around the Sun. Thus, observing it over even a short duration will see it move in a retrograde way against the background stars, that is almost entirely due to parallax rather than orbital motion. Getting a good orbit will need observations over ...

1

It is a process of orbit determination. The apparent position of any solar system body will change from night to night as a result of the combination of its actual motion around the sun and the motion of the Earth. A very distant body such as "Farout" will be moving very slowly. To determine an orbit, a minimum of three observations is needed. From three ...

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