We know that the faster you move, the slower your time is perceived from an external observer and the space along the direction of the movement shrinks. Photons, having no mass, move at the speed of

I am doing some research for a video game and I wanted to store stellar data on a star, such as its Stellar Classification, and then from that derive a physical appearance in the game. These are

Many websites say this is because the effective focal length of the objective is increased by making the secondary mirror convex. This allows a Cassegrain telescope to be shorter than a similarly p…

If I want to measure the beam-width of a radio telescope sweeping through a ~ puntual object (the Sun) with a ~ constant flux output when measured: The value measured sweeping in one frame of refe…

The Hubble Space Telescope has managed to photograph images of the oldest galaxies that had been observed so far. These are seven primitive galaxies that originated more than 13,000 million years ago, between 350 and 600 million years after the Big Bang. At that time the Universe was 4 percent of its current age.

Do you have in mind any database/sites that I can search for stars that matches a given surface temperature and an absolute magnitude? For example, when I enter Temperature=9,500K &