https://www.space.com/31677-astronomers … -nine.html
January 21, 2016

"Even at its most distant, and at the smallest guesses of how big it is, it's like 24th or 25th magnitude," Brown said, referring to the brightness scale astronomers use, in which higher numbers denote fainter objects. "It's not crazy; this is the kind of stuff people are finding all the time. We just need to go out and cover a good swathe of the sky."

Just how big a swathe? Astronomer Scott Sheppard, of the Carnegie Institution for Science in Washington, D.C., has come up with a rough estimate: between 2,000 and 4,000 square degrees. (For perspective, the full moon as seen from Earth covers about 0.5 degrees of sky.)

That corresponds to about 50 nights of observations using a powerful instrument such as the Subaru Telescope in Hawaii, said Sheppard, who has a lot of experience finding far-flung objects in the solar system. For example, in 2014, he and Chadwick Trujillo of the Gemini Observatory in Hawaii discovered an object called 2012 VP113, whose orbital characteristics hint at the presence of a Planet Nine.

https://www.scientificamerican.com/arti … st-planet/
October 25, 2016

"However, these estimates still leave a swath of sky "about 1,500 square degrees large," says astronomer Scott Sheppard at the Carnegie Institution for Science, who with astronomer Chadwick Trujillo first suggested the existence of Planet Nine in 2014. (In comparison, the full moon as seen from Earth covers about 0.2 degrees of sky.) This swath described by Sheppard corresponds to about 20 nights of observations on Subaru, "and if we get seven nights or so this year, that's three years—if it's not rainy any of those nights," Sheppard says.
So the strategy in the race is now largely a matter of reducing the search area by eliminating theoretical possibilities. In an as-yet unpublished set of about 100 new high-resolution computer simulations, Batygin says he and Brown have narrowed down Planet Nine's location to a roughly 600- to 800-square degree patch of sky. They first modeled the solar system over the course of about 4 billion years, focusing on how the gravitational pulls of the system’s largest planets—Jupiter, Saturn, Uranus, Neptune and Planet Nine—might have sculpted the orbits of thousands of randomly scattered Kuiper Belt objects (KBOs). "We're searching for all of the things that Planet Nine does to the solar system," Brown says."

https://arxiv.org/pdf/1603.05712.pdf

We began a survey of these regions in the fall of 2015 and will attempt to cover all of this part of the predicted orbital path.

https://www.naoj.org/Observing/Schedule/s16b.html

S16B-049, Fumi Yoshida et al.,
Hunting Planet Nine and RR-Lyrae stars in the Milky Way halo with HSC
HSC, 3 nights, abstract

https://www.naoj.org/Observing/Schedule … 6B-049.txt

(Proposal ID) S16B-049

(PI) Yoshida, Fumi

(Proposal Title)
Hunting Planet Nine and RR-Lyrae stars in the Milky Way halo with HSC

(Abstract)
We request 20 nights to conduct an HSC g-band cadence observation (2 visits per night and 8 visits of the same field in total) over ~800 sq. degrees in order to hunt down the theoretically predicted giant planet, "Planet Nine". The combination of large aperture, wide field-of-view, and exquisite image quality of HSC/Subaru enables us to reach the required depth of 25~mag (AB) with 90~sec exposure for each visit, allowing us to cover the entire high-probability regions where Planet Nine should be currently located.  Planet Nine, if discovered, promises to revolutionize our knowledge of the origin of the solar system, the physics of giant planets, and the connection to exoplanetary systems. In addition to this high-risk, high-return scientific goal, the same data will allow us to carry out the following guaranteed science: discovery of ~0.2M main-belt objects and ~10^4 Kuiper-belt objects in this previously unexplored region, in addition to the discovery of more than 1,500 RR-Lyrae (RRL) stars in the halo region of the Milky-Way (MW), about 100 of which will lie at distances in the range 100-700kpc (the virial radius of the MW is ~300kpc). The distribution of RRL stars will allow us to study the structure of the MW dark matter halo and to possibly detect its outer edge.

https://www.naoj.org/Observing/Schedule/s17b.html

S17B-044 Fumi Yoshida Hunting Planet Nine and RR-Lyrae stars with HSC HSC 1.5

https://www.naoj.org/Observing/Schedule/s18b.html

S18B-071 Fumi Yoshida Hunting Planet Nine and RR-Lyrae stars with HSC HSC 3

12 ноября 2015
4 марта 2016
26-29 сентября 2016 года (по полночи)
3-4 октября 2016 года (по полночи)
21-25 сентября 2017 (по полночи)
15 декабря 2017 года (по полночи)
16-17 декабря 2017 года (первая ночь по полночи, вторая ночь целая ночь)
21 января 2018 года (по полночи)
8-10 февраля 2018 года (по полночи)
1-4 ноября 2018 года (по полночи)
7 и 9 декабря 2018 года (по полночи)
3-9 декабря 2018 года (по полночи за исключением 8 декабря) (какая-то малоизвестная программа под фамилией Браун?)

https://www.space.com/42177-when-will-w … -nine.html

October 18, 2018 07:30am ET

Indeed, the search has so far covered just 20 percent to 25 percent of "premium sky," the regions where Planet Nine is most likely to be, both Sheppard and Batygin said.

Отредактировано Пользователь1 (2018-11-11 15:47:52)