How long is that tidal trail
by Budgieye moderator
what could cause such a long star stream? What is it -a few tens of thousands of light years?
The image is 60arcsec. so half of that 30 arcsec
Estimate distance to galaxy, well, no hint of yellowing so say z=0.01, or 138,000,000 light-years away, using Wolfram
Redshft conversion website
Find a nice website http://chandra.harvard.edu/photo/scale_distance.html, use example 3. Plug in numbers
0.019871 million light-yearslong or 19,871 light-years, so your estimate of a few tens of thousands is quite good.