[ExI] First Picture of a Black Hole!

[Stuart LaForge]

Tomaz Kristan wrote:

>
> Shouldn't it be the Sagittarius? Much smaller and much closer one?
>
> Why is that now?
>
> On Wed, Apr 10, 2019 at 3:38 PM John Clark <johnkclark at gmail.com> wrote:
>
>> https://www.nytimes.com/2019/04/10/science/black-hole-picture.html
>>

As John pointed out their angular widths should be about almost equal  
at 5:4 for SgrA* vs M-87*. While there is a lot of dust between us and  
SgrA*, that shouldn't affect meters-wide radiowaves. So my guess is  
that the paper published back in January that suggested that the radio  
jet of Sagittarius A* is pointed directly at us is actually correct.

http://www.astronomy.com/news/2019/01/radio-jets-from-the-milky-ways-black-hole-could-be-pointing-right-at-earth

The radio jet pointing directly at us would make the picture of SgrA*  
just look like a bright blotch of light with no dark "shadow" apparent  
so it would not look much like a "black" hole. Even in the picture  
M-87* they have, the shadow is not quite as dark as the peripheral  
space suggesting there is some radio emission occurring between it and  
us.

And also, I know they billed it as a mere "picture" but would it have  
killed them to put in some form of scale or the galactic plane of M-87  
or something for reference? The shadow of the BH looks like an ellipse  
elongated in the NE to SW direction. That could be the equatorial  
plane of the black hole's rotation in which case it would be spinning  
pretty fast. But with no frame of reference it might as well be a  
photo of a UFO.

Stuart LaForge