"They were not like us" story

[Viktor Kuprin]

Anyone know the title/author of this wonderful short story?

An interstellar expedition is sent to study a black hole/singularity. En route they pass a star system containing what had been an inhabited planet, now destroyed by the super-nova which created the singularity. They arrive at the black hole and encounter an alien starship that's also there on a study mission. Video and audio communication is established. The aliens are horse-like in appearance. They're asked if there were aware of the previously inhabited planet in the nearby star system. Yes, they knew them and had had contact with them. They're asked if they warned that race about the approaching, deadly super-nova. Their reply reveals much: "Why should we have warned them? They were not like us. They were of no concern to us." This chilling answer foretells the story's ending.

I remember this being in a volume filled with short stories, and this one was the best.