Answer:
The object is most likely to be a (distant) galaxy
Explanation:
Distance of galaxies are often calculated based on the unit of light year.
The abbreviation, mpc which translates to mega parsec
A mega parsec is equivalent to 3.3 light years.
So, if the astronomer sighted the object from a distance of 28mpc which is equivalent to 28 * 3.3 light-years (92.4 light years); the object is most likely to be a galaxy; a distant galaxy
