Ton 490

Ton 490 is a quasar of magnitude 15.4 (slightly variable). At this brightness it should be visible in a 12" telescope, and under dark skies, may also be visible in a 10". Ton 490 has a redshift (z) of 1.631, which equates to a distance of around 8000 million light years!! This means that the light has been travelling for about twice as long as anyone claims the Earth has been in existence. Something to try and ponder when observing it. That little faint star is really one of the brightest objects in the universe??!!!??

Ton 490 is well placed for northern hemisphere observers now as it is situated in the northern portion of the Sickle of Leo.

Below is an image of Ton 490 that I took recently and several maps to assist observers in locating this very distant object. The first map is a large scale map showing the general area around the quasar. The second chart shows an area of about 2 degrees adn includes the quasar and the nearest bright star. (zeta leonis) This is for use at the finder. The final chart is a small-scale map of the quasar showing stars to magnitude 16, and is for use with the main telescope.

Combination of 5, 2 minute exposures, SBIG ST-8E CCD.
8" f/6.3 schmidt-cassegrain telescope at prime focus.

Wide Field chart

Medium field chart

Narrow field chart

Narrow field chart