| Emission nebula | |
|---|---|
| Herbig–Haro object | |
Hubble WFC3 image of HH 111
| |
| Observation data: J2000.0 epoch | |
| Right ascension | 05h51m 44.2s[1] |
| Declination | +02° 48′ 34″[1] |
| Distance | 1500[2] ly |
| Constellation | Orion[2] |
| Designations | HH 111 |
| See also: Lists of nebulae | |
HH 111 is a Herbig-Haro object in the L1617 dark cloud of the Orion B molecular cloud[2] in the constellation of Orion. It is a prototype of a highly collimated optical jet sources. It shows several bow shocks and has a length of about 2.6 light-years (0.8 parsec).[3]
HH 111 is about 1300 light years (400 parsec) distant from earth and the central source is IRAS 05491+0247, also called VLA 1.[2] This source is the driving source of the jets and it is a class I protostar with a luminosity of about 25 L☉. This protostar is embedded in a 30 M☉ cloud core.[4] The dynamical age of the complex is only 800 years.[4] Near the central source an ammonia feature called NH3-S was found, which is a starless core with a turbulent interior induced by HH 111.[2]
The jets move with a speed of 300 - 600 km/s and consist of a blueshifted component, which is bright in optical wavelengths and a redshifted faint counterjet.[4] A second pair of bipolar jets, called HH 121 was discovered in the near-infrared at an angle of 61° compared to the HH 111 pair. This was taken as evidence for a system with multiple protostars.[5][6]
