|Magnitude: +12.9||Redshift: 0.158|
|Distance: 2.443 billion light years.||FOV: 71.7 x 47.6 arcmin|
|Exposure: 225 sec x 4 = 15 minutes||Orientation: Up is 230 degrees E of N|
|Image Date: 2021-04-02|
Quasar 3C 273
This was the first quasar to be identified. It is optically the brightest quasar in the sky and is also one of the closest. It’s estimated distance is over 2.4 billion light years. Yes that’s right, you read the word ‘billion’ correctly.
3C 273 looks just like any common old star in our own galaxy – but it lies at the centre of a remote giant elliptical galaxy an astounding 2.4 billion light years away!
This is my first quasar image and it’s hard to imagine that such an incredibly distant object could be captured with a mere 120mm diameter refracting telescope. Realistically, at magnitude 12.9, it’s well within the reach of amateur telescopes.
What is a Quasar?
These are objects which have extremely luminous active galactic nuclei, with a supermassive black hole surrounded by an accretion disc. Gas in the disc emits electromagnetic radiation as it falls towards the black hole. The most powerful quasars have luminosities thousands of times greater than a galaxy such as the Milky Way.
How Do I know it’s the Quasar?
For the record, here is the verification image from the Aladin website which enabled me to identify the object in my own image by recognising the unique star patterns around it.. Note the purple crosshairs. Unlike my image, this is North up.
Location of 3C 273 in Virgo
Location of Virgo Constellation
Images courtesy of nova.astrometry.net
If the images do not appear it is because the Astrometry website is sometimes off line.
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.|
|Field flattener; ZWO Duo-band Hα (656nm) and [OIII] (500nm) filter.|
|SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.|
|Imaging camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx).|
|Software: Telescope control: Cartes du Ciel, EQMOD, PHD2, Imaging: SharpCap, Gimp.|
|Observatory location: 34° South.|
Images © Roger Powell
I’m a founder member of Macarthur Astronomical Society