Displaying items by tag: Quasar
NGC 3079 is a barred spiral in Ursa Major, but for me the real "star" in this image is the Twin Quasar. Which is a single quasar that appears doubled by gravitational lensing by a foreground galaxy. It took the light 8.7 billion years to arrive here. The light from one component takes an additional 14 months to arrive having taken a longer path. This was the first observable object demonstrating the effects of gravitational lensing.
Somewhere in this image is Quasar 3C 273, an extremely distant galaxy, but shines with the light of a near by star. When first discovered, the presented a paradox. In images they look like a star, but their red-shift, the amount their light is shifted towards the red side of a spectrum, suggested an object billions of light years away. The name quasar is a abbreviation from quasi-stellar object (QSO). 3C 273 was the first object to be identified as a quasar. It is one of the brightest and closest optical quasars to us at 2.4 billion light years away when the light left the object. A quasar is active galactic nucleus that is powered by supermassive black hole that is surrounded by an accretion disk with in falling material. The luminosity given off can be several thousand times brighter than an entire galaxy.
The quasar is also known as galaxy PGC 41121 and is near the very center of the image.
3C 147 is a quasar located in the constellation of Auriga. A quasar is a term that originated with the term quasi-stellar object (QSO). When first discovered, they looked like stars, but their spectrum resembled a galaxy, and when their red-shift of their spectrum was measured, it indicated an object at extreme distance, which was quite a paradox. They now are identified as a active galactic nucleus powered by a super massive black hole with in-falling matter creating a light source that can be thousand times brighter than an entire galaxy. The red-shift of 3C 147 indicates that the light we see today took 5.1 billion light-years to reach us.
NGC 6503 Nicknamed the Lost in Space Galaxy as it sits on the edge of an area of space devoid of galaxies that is called the Local Void. A dwarf galaxy at one third of the size of the Milky Way it located in Draco at a distance of 17 million light years away. Also tracked down two quasars that are visible in the image.
Imaged with the ES127 refractor and Atik314l+ mono camera over multiple nights.
The Twin Quasars were one of the first observable effects of gravitational lensing. Light passing through a galaxy YGKOW G1 and its associated cluster located between Earth and the quasar is bent by the gravity of the galaxy cluster to form the double image.
Interestingly the light from the "b" image arrives about 14 months later than from the "a" image due to the extra distance it travels due to the lensing effect. The by redshift measurement of the quasar the estimated distance is 7.9 to 14 billion light years away. The quasar is near magnitude 17, and the images are separated by 6 arc-seconds and is located in the constellation of Ursa Major.
Hubble Image: http://www.spacetelescope.org/images/potw1403a/
Color images taken with the 80 mm refractor, and the inset image was taken with a larger 254 mm scope.
Blazar CTA 102 is another blazar that has flared up recently. Discovered in the 1960s by radio telescope surveys.The unidentified radio source was originally speculated to be aliens, but was later identified as a type of quasar.
The blazar which has been in an active state since 2015 has greatly increased in brightness at the end of November. The blazar is located in the constellation of Pegasus.
Imaged with the 80mm refractor and monochrome ccd camera using R/G/B filters.
While it might not look impressive in this image, consider that most of the stars visible in this image are only a few thousand light years away, while OJ 287 is 3.5 billion light years away. What powers this system is a black hole, and not just any black hole, but a super massive black hole. It is among one of the largest found at a mass of 18 billion solar masses. But there is more, it is orbited by another black hole. The companion's orbit is decaying and is expected to merge with the central black hole within 10,000 years.
This "star" was originally assumed to be a variable star with a 11-12 year cycle. It wasn't until the red shift of its spectrum was measured placing it at its extreme distance. When these types of objects were originally discovered, it was quite the mystery of what could be generating that amount of energy. It wasn't until the theories of black holes that this amount of energy could be explained. Quasars, of which OJ 287 is a type of, are powered by super massive black hole at the center of a galaxy. In falling matter to the black hole's accretion disk creates the energy. The energy is generated by intense gravitational forces and friction in the accretion disk. A typical quasar consumes 10 to 1000 solar masses per year.
OJ 287 is considered a blazar, which is a type of quasar where the jets emitted perpendicular to the accretion disk point in the general direction of Earth, increasing the brightness of the object.
If that isn't enough, there is always the nice "carbon" star T Cnc in the upper left corner. A carbon star is usually a red giants variables with lots of carbon in their outer gas shell. It is very good at absorbing other colors from the star, resulting in a deep reddish-orange hue.