This is the red supergiant star Betelgeuse in the constellation of Orion.
The image on the left is from 2019 October 23 and the image on the right from 2019 December 28, 67 days apart.
Both are 15 second exposures but on different cameras, on the left a Canon Powershot ELPH 120 with ISO 800 and on the right a Canon 300D with ISO 1600.
Ideally one would want to use the same camera, the same object framing, same ISO and same exposures to compare, but even so, the difference in brightness stands out.
Betelgeuse has dimmed significantly in the last few months.
One can also go to the AAVSO website and generate a light curve, as I have done here below, showing brightness numbers from October 23 to Jan 12

Without numerical analysis, just looking at the curve shows a change from about magnitudes 0.5 to 1.5

You can go here to generate your own light curve to keep track of the star.

https://www.aavso.org/apps/webobs/results/?star=BETELGEUSE
or
https://www.aavso.org/LCGv2/