Discoveries using the telescopes on Mauna Kea

[TomK]

PS. A nice piece of background reading for anyone interested:

https://www.vox.com/science-and-health/2...-like-what

[HereOnThePrimalEdge]

Thanks TomK,
It should be an intriguing press conference tomorrow. The entire project up until now has been fascinating, the organization & coordination of the observatories for a start. The video of stars orbiting a black hole in your vox.com link was incredible.

[TomK]

I may have this wrong, but just did a quick calculation. It's late at night, so don't hold me to this, but think in order to make this observation, the observatories around the world, including those on Mauna Kea, had to produce data that could be flagged with time data that was more precise than 3 pico-seconds (i.e., less than 3 trillionths of a second).

As I said, I may not have got this right, I'm not an interferometry expert, but am interested to see what's announced.

[PaulW]

And here it is:
https://www.bbc.com/news/science-environment-47873592

Great work by all involved!

[HereOnThePrimalEdge]

Because Hawaiian telescopes were instrumental in this achievement, the black hole has been named Powehi. Happy Powehi Day!

With the M87 galaxy black hole photographed, scientists in Hawaii approached Larry Kimura, University of Hawaii-Hilo Hawaiian-language professor, about naming the object in Hawaiian.
Kimura came up with the name Powehi, which translates into “adorned fathomless dark creation.” In a proclamation, Gov. David Ige is declaring today “Powehi Day“ in Hawaii.

“So many astronomers came to Hawaii from all over the world. Our control room at the James Clerk Maxwell Telescope isn’t very large compared to others, but it was extremely crowded. It was very exciting,” Dempsey said.

https://www.staradvertiser.com/2019/04/1...178dfe24e8

[HereOnThePrimalEdge]

TomK,
It seems like the event horizon project was a great success.
Do you know of any other objects in space for which this worldwide linkup of telescopes could be used?
Other distant bodies that we’ve so far been unable to observe, or view with any clarity?

[HereOnThePrimalEdge]

Here’s an overlay showing the size of our solar system compared with the black hole. It’s BIG:

https://pbs.twimg.com/media/D30Ul9nWwAE9i_x?format=png&name=900x900

[TomK]

"Do you know of any other objects in space for which this worldwide linkup of telescopes could be used?
Other distant bodies that we’ve so far been unable to observe, or view with any clarity?"

I'll ask if they plan to do other targets other than blackholes, but their main targets are M87 and Sgr-A, i.e., the massive black hole at the center of our Galaxy. Their aims are to test Einstein's theories, understand the physics of accretion around black holes and how powerful jets form and are collimated (i.e., what forces them to emerge in certain directions). For the time being I think that's what they'll stick to as that's how they got funded. Other targets in the future could include star-forming regions in the Galaxy (such as M42 in Orion), which tend to be quite bright at the wavelengths the EHT works at, so they might start to look at jets and dust/gas inflow and outflows in such regions - it's another big area in astrophysics that isn't understood that well.

[TomK]

For those who may be a bit underwhelmed, think about this:

This is the image of the black hole and the surrounding matter orbiting the black hole:

https://static.projects.iq.harvard.edu/files/styles/os_files_xlarge/public/eht/files/20190410-78m-800x466.png?m=1554877319&itok=m0gPFSet

The diameter of the ring is about 42 micro-arcseconds. The average natural seeing on Mauna Kea at optical wavelengths is about 0.5 arcseconds which means that without using any fancy optics, an optical/infrared telescope on Mauna Kea would image a point-source, such as a star, and the stars image would be a big ball of blurriness about 10,000 times larger than the image of the M87 system shown in the above link.

In other words, the black hole image is much more than 10,000 times clearer than an uncorrected image taken at one of the best observing sites on the planet.

I'll have to recheck my math. I knew the resolution of the EHT would be stunning, but not quite that amazing. Even with the best adaptive optics which have achieved on order 50 milli-arcsecond seeing on MK, the M87 image is thousands of times more detailed.

[HereOnThePrimalEdge]

For the time being I think that's what they'll stick to as that's how they got funded.

Thanks.
It sounds as though there’s plenty researchers can study on M87 & Sgr-A, including any changes that occur over an extended period of time. Unique characteristics could appear, disappear, and reappear over years and decades.

I loved the photo of the 29 year old woman, who worked on developing the algorithm which connected information from participating telescopes around the world. She posed with a table full of hard drives in front of her, showing the amount of computer memory required. Impressive.

I also appreciated that a member of staff at UH-Hilo named the black hole, it puts little Hilo on the international stage in a positive manner. Thanks to the astronomy community here on Hawaii Island the Hawaiian language was also brought front and center again as with Oumuamua, dwarf planet Haumea, and the Laniakea Supercluster.

It puts us on the map in many ways.