NGC 7727 is a peculiar galaxy in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Aquarius Aquarius may refer to: Astrology * Aquarius (astrology), an astrological sign * Age of Aquarius, a time period in the cycle of astrological ages Astronomy * Aquarius (constellation) * Aquarius in Chinese astronomy Arts and entertainment ...

. It harbors two galactic nuclei, each containing a supermassive black hole, separated 1,600

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s apart.

Features

This object is located at a distance of 23.3 mega parsecs (76 million

s) from the Milky Way and has a peculiar aspect, with several plumes and streams of irregular shape that explains its inclusion on Halton C. Arp's Atlas of Peculiar Galaxies with the number 222, being classified as a "Galaxy with amorphous spiral arms". In all likelihood, this system is the product of the

merger Mergers and acquisitions (M&A) are business transactions in which the ownership of companies, other business organizations, or their operating units are transferred to or consolidated with another company or business organization. As an aspect ...

of two previous spiral galaxies that took place 1 billion years ago, with the aforementioned stellar plumes and streams being the remnants of the disks of the two galaxies that collided to form this object. Two starlike objects can be seen in NGC 7727's center, at least one of them likely being the former core of one of those two spiral galaxies. In addition to this, 23 objects – candidates to be young globular clusters formed in the collision – can be found in this system. NGC 7727 is very similar to

NGC 7252 NGC 7252 is a peculiar galaxy resulting from an interaction between two galaxies that started a billion years ago. It is located 220 million light years away in the constellation Aquarius. It is also called Atoms for Peace Galaxy, a nickname whic ...

, another galaxy product of the collision and merging of two former spiral galaxies, in the same constellation. However it has far less gas (

neutral hydrogen The hydrogen line, 21 centimeter line, or H I line is the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms. This electromagnetic radiation has a precise frequency of , w ...

and molecular hydrogen) than the latter. NGC 7727's most likely fate is to become an elliptical galaxy in the future, with very little interstellar dust and

star formation Star formation is the process by which dense regions within molecular clouds in The "medium" is present further soon.-->interstellar space

In November 2021, scientists announced the discovery of a pair of supermassive black holes in NGC 7727, detected with the Very Large Telescope's

multi-unit spectroscopic explorer The multi-unit spectroscopic explorer (MUSE) is an integral field spectrograph installed at the Very Large Telescope (VLT) of the European Southern Observatory (ESO). It operates in the visible wavelength range, and combines a wide field of vie ...

(MUSE) at the

European Southern Observatory The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 mem ...

. The black holes have masses of 154 and 6.3 million solar masses, and are separated 1,600 light years apart. The pair are among the closest confirmed supermassive black holes to Earth at about 89 million light years away. Although the pair are separated closely enough to gravitationally influence each other, the smaller black hole is not bound in orbit around the larger black hole due to the surrounding mass of the NGC 7727 core region. The black holes will eventually merge in the next 250 million years, producing powerful, low-frequency

gravitational wave Gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1 ...

s in the process.

References

External links

* {{DEFAULTSORT:NGC 7727 Interacting galaxies Aquarius (constellation) 7727 72060

222 __NOTOC__ Year 222 ( CCXXII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Antoninus and Severus (or, less frequently, ye ...

Features

See also

References

External links