HH 111 is a Herbig-Haro object in the L1617 dark cloud of the Orion B molecular cloud in the constellation of Orion. It is a prototype of a highly

collimated A collimated beam of light or other electromagnetic radiation has parallel rays, and therefore will spread minimally as it propagates. A perfectly collimated light beam, with no divergence, would not disperse with distance. However, diffraction pr ...

optical jet sources. It shows several

bow shock In astrophysics, a bow shock occurs when the magnetosphere of an astrophysical object interacts with the nearby flowing ambient plasma such as the solar wind. For Earth and other magnetized planets, it is the boundary at which the speed of ...

s and has a length of about 2.6

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 (0.8

parsec The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and ...

). HH 111 is about 1300 light years (400 parsec) distant from earth and the central source is

IRAS 05491+0247 The Infrared Astronomical Satellite (Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten mont ...

, also called VLA 1. This source is the driving source of the jets and it is a class I

protostar A protostar is a very young star that is still gathering mass from its parent molecular cloud. The protostellar phase is the earliest one in the process of stellar evolution. For a low-mass star (i.e. that of the Sun or lower), it lasts about 5 ...

with a luminosity of about 25 . This protostar is embedded in a 30 cloud core. The dynamical age of the complex is only 800 years. Near the central source an

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...

feature called NH₃-S was found, which is a starless core with a turbulent interior induced by HH 111. The jets move with a speed of 300 - 600

km/s The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in ...

and consist of a

blueshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in fr ...

ed component, which is bright in optical wavelengths and a

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

ed faint counterjet. A second pair of bipolar jets, called HH 121 was discovered in the

near-infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...

at an angle of 61 ° compared to the HH 111 pair. This was taken as evidence for a system with multiple protostars.

Gallery

File:Herbig-Haro 111.jpg, The bright blueshifted jet of HH 111 seen by the ground-based telescope NTT File:HH 111 Spitzer.jpg, HH 111 seen by the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...

in infrared, showing also HH 121 File:HH 111 jet movement.gif, Animation of HH 111 (Hubble image), showing the movement of the jet and bow shock

References

External links

{{Commons category, HH 111
Animations of HH object jets from HST observations

Herbig–Haro objects Orion (constellation) Orion molecular cloud complex