#Virgo constellation skychart pdf#
#Virgo constellation skychart plus#

Click the graphic for a PDF version suitable for printing. Celestial north is up and east is to the left. Stars FW and 16 Virginis are common to the wide-field Virgo chart to give you a sense of scale. The inner circle is one degree wide, or the field of view of a typical eyepiece at 45 to 50× magnification. However, even if your computerised mount automatically takes you to the correct location 3C 273 is indistinguishable from faint foreground stars, so you still need a detailed finder chart like the one below ( click here for a PDF version): This detailed narrow-field finder chart for 3C 273 shows an area of sky just five degrees wide centred on the quasar with field stars down to magnitude +13. The easiest way to locate 3C 273 is with a computerised GoTo telescope, or an instrument equipped with digital setting circles. Given that this quasar is slightly brighter than magnitude +13, it’s a viable target for a 15-cm (6-inch) telescope under dark skies. And despite all subsequent quasar discoveries, 3C 273 remains the brightest quasi-stellar object at optical wavelengths. We now know that such a quasar is an extremely luminous active galactic nucleus (AGN), powered by a supermassive black hole. To have a magnitude of +12.9 at such a distance implies that the quasar has a phenomenal luminosity – so bright, in fact, that 3C 273 is at least 4,000,000,000,000 times more luminous than the Sun at visible wavelengths. A redshift of 0.158 reveals that 3C 273 is much farther than either the Virgo or Coma Clusters – a staggering 2,443 million light-years away. AN graphic by Ade Ashford.Named for its ranking as the 273rd object in the Third Cambridge Catalogue of Radio Sources published in 1959, occultation studies of 3C 273 reveal it to be associated with an unresolved stellar object having an apparent magnitude of +12.9. Click the graphic for a PDF version of the chart suitable for printing. FW Virginis (variable from magnitude +5.6 to +5.8) and 16 Virginis (magnitude +4.9 to +5.0) lie either side of 3C 273, the area shown in greater detail down the page. Exceedingly remote yet relatively bright is quasar 3C 273 located 4.7 degrees northwest of the beautiful double star gamma (γ) Virginis, otherwise known as Porrima. The so-called Bowl of Virgo is a happy hunting ground for galaxy devotees, containing a dozen Messier and scores of NGC objects.

#Virgo constellation skychart plus#

While the distances to the centres of these galactic conglomerations are truly mind-boggling – 54 million and 320 million light-years, respectively, for the Virgo and Coma Clusters – they are relatively close compared to a peculiar object designated 3C 273, found within the so-called Bowl of Virgo bounded by epsilon, delta, gamma, eta and beta Virginis, plus beta Leonis (Denebola). This is the time of year when you can while away moonless nights trawling the constellations of Leo, Virgo and Coma Berenices, where an 8-inch (20-cm) aperture telescope (or larger) will net you literally hundreds of catalogued galactic goodies. Image credit: Ade Ashford.As any keen Northern Hemisphere deep-sky observer knows, the arrival of spring means that it’s open season for galaxies. Amazingly, you can see this quasar in a 15-cm (6-inch) aperture telescope. It is the extremely luminous core of an active galaxy powered by a supermassive black hole and lies a staggering 2,443 million light-years distant, receding from us at 14.6 percent of the speed of light. Known as 3C 273, this was the first quasar to be identified and the optically-brightest at magnitude +12.9.

This star field in the constellation of Virgo is unremarkable, except for the arrowed object.