Archive for May 10, 2022

05/10/2022 – Ephemeris – Event Horizon Telescope Collaboration will announce “groundbreaking Milky Way results” on Thursday

May 10, 2022 Comments off

This is Ephemeris for Tuesday, May 10th. Today the Sun will be up for 14 hours and 38 minutes, setting at 8:58, and it will rise tomorrow at 6:19. The Moon, 2 days past first quarter, will set at 4:25 tomorrow morning.

This Thursday, May 12th at 13:00 UT (9 am our time EDT) the Event Horizon Telescope Collaboration will announce “groundbreaking Milky Way results.” Their words. Their first groundbreaking result came in three years ago with the release of an image of the billion solar mass black hole in the heart of the giant galaxy M 87 over 50 million light years away. Beforehand, I was expecting the results to concern a more nearby black hole called Sagittarius A* (pronounced Sagittarius A Star) at the center of our galaxy, only 25 to 27 thousand light years away. That turned out to be much more difficult than the one in M 87, due to the amount of dust and gas in the way. So maybe this time they have done it. We’ll all find out this Thursday.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.


Black hole in M87

The first image of the black hole in M87. Credit Event Horizon Telescope.

The Event Horizon Telescope isn’t a single telescope. But millimeter wavelength radio telescopes spaced out to use the diameter of the Earth as its simulated aperture. The ability to resolve tiny objects at great distances depends on the wavelength of the radiation and the size of the telescope aperture. So the smaller the wavelength and the larger the aperture, the greater the resolution of the telescope or array.

The observation of all the telescopes must be performed at the same time, recording the observations on terabyte magnetic disks. The disks are brought to a single location for processing together to actually produce the image, which takes a while.

Event Horizon Telescope

Event Horizon Telescope component radio telescopes. Credits: © APEX, IRAM, G. Narayanan, J. McMahon, JCMT/JAC, S. Hostler, D. Harvey, ESO/C. Malin.