Interacting object

https://www.legacysurvey.org//viewer/?ra=19.0959&dec=2.1096&layer=hsc-dr2&zoom=16&ngc&bright&photoz-dr9&const

The red object is a foreground star, so it definitely isn’t interacting with the galaxy. Just chance alignment.

How can I see that it is a star? I thought stars were different. Next to these objects there is a bright star, but its light has a different shape - it has the typical diffractions.

It has significant proper motion in gaia, and a parallax of 0.4. Definitely a star. Its very distant, but definitely within our galaxy. It’s very faint (likely due to its distance), at almost 18th mag, which is why we don’t see diffraction spikes/artifacts which we see on the nearby star you mentioned which is quite bright at 13th mag.

Thank you… but where do I find gaia?

I have found gaia