Orion travels over Bangalore's nighttime sky. The amount of light in the sky over the city is much higher than that over Hampi and the sky shows up as a hazy dirty orange rather than black. You can see the haze at the bottom of the window that's more haze from IISc street lamps, building lights and such like. If you set the WB on your image to tungsten light it sets back to this nice blue, so I'm guessing most of the stray light has this temperature.
I took this at f10 (and the light still shows up!) for about 20 minutes at 200 ISO. Pointed it high up in the sky to avoid as much background light as possible. I also sat so my shadow fell on the camera cutting off some ambient light as well. I also shut off the long exposure noise reduction option on my camera which meant the camera didn't lock up for a long time after a shot. There is some noise, you can deal with most of it using some noise reduction software.
Only thing being I wish I would think to do these things in summer. It was freezing up on the roof. Not too many people really go up on the hostel roof and a girl saw me climbing up and apparently called and asked who I was. I predictably didn't hear her and carried on. A while later there were two girls standing on a ledge facing the roof looking up. I thought they were out looking at stars or something so I carried on setting up my shots. After a bit there were 3 and I figured they were looking at me and wondering what the f*** I was upto and who I was. I must've looked nice and suspicious in my black turtle neck! I asked them if something was the matter and I think they either figured out who I was or at least realized I was also a girl, because the relief was obvious in their laughter!