# How many solar masses is the central black hole in the Whirlpool Galaxy?

I am having trouble finding the mass of the central black hole in the Whirlpool Galaxy M51a/NGC5194, it is stated that its companion galaxy NGC5195 has a supermassive black hole at its centre that is 19 million solar masses but I can't find details on the Whirlpool Galaxy's central black hole, is its mass known?

• Maybe it's hard to make a good mass estimate with all the dust obscuring the centre of NGC 5194. Jul 26 '20 at 17:30
• Using the HyperLEDA mean central stellar velocity dispersion for M51a ($\sigma = 88$ km/s) and the $M_{\rm BH}$-$\sigma$ relation from Saglia et al. (2016), one would predict $M_{\rm BH} \sim 3 \times 10^{6} M_{\odot}$. That is not, of course, an actual measurement.... Dec 28 '20 at 15:46

It is not well known, but a paper by M. Brightman et al gives a value of $$10^{6.3\pm0.4}$$ or between 8 hundred thousand and 5 million solar masses, while noting that this estimate is lower than previous estimates which had $$10^{6.95}$$ or about 9 million masses.