This image has been produced with the little data I could gather during the cloudy months of January and February 2024, by picking the few fragmented hours of clear sky available.
Processing proved to be extremely difficult, due to the faintness of the nebulosity and the insufficient exposure time.
The first version of the image was pure RGB. I added in a second round HOO Signal (in the final version I used only the Ha channel).

This interesting but obscure area of intense stellar formation includes the Cosmic Keyhole, a hole that has been literally carved out in the molecular cloud by a jet originated by one of the four stars of V380 Ori system. This is also the place where the first Harbig Haro (HH) objects where identified and numbered. A few of them, including HH number 1 and 2 are shown in the annotated revision.

NGC 1999
Also known as The Cosmic Keyhole, is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. It is a reflection nebula, and shines from the light of the variable star V380 Orionis.
It was previously believed that the black patch was a dark nebula in front of the reflection nebula. Analysis of this patch by the infrared telescope Herschel (October 9, 2009),  Atacama Pathfinder Experiment radio telescope (November 29, 2009) and the Mayall (Kitt Peak) and Magellan telescopes (December 4, 2009), determined that the patch looks black not because it is an extremely dense pocket of gas, but because it is truly empty. The exact cause of this phenomenon is still being investigated, although it has been hypothesized that narrow jets of gas from some of the young V380 stars punctured the sheet of dust and gas, as well as, powerful radiation from a nearby mature star may have helped to create the hole.

HH 1/2, HH33 and the other HHs
It is located 1,500 light-years away from Earth in the constellation Orion. HH 1/2, the first recognized Herbig-Haro Object, is located near NGC 1999.

V380 Ori Star System (nothing to do with Hollywood Star System)
It is a young multiple (3 or 4) star system located near the Orion Nebula in the constellation Orion, thought to be somewhere between 1 and 3 million years old. It lies at the centre of NGC 1999 and is the primary source lighting up this and other nebulae in the region.
The main component is visible as the 10th magnitude variable star at the centre of NGC 1999, referred to as the primary. Speckle interferometry shows a cool companion separated by 0.15", approximately 62 AU, referred to as the tertiary. Spectroscopy shows a third star at a projected separation less than 0.33 AU, referred to as the secondary. The two closest stars, the primary and tertiary, are surrounded by a circumstellar disk, lying almost edge-on to observers on earth. The fourth star has a projected separation of 4,000 AU and is receding from the other three.
The system is believed to have formed with all four stars close together, but interacted to eject the smallest star into an unstable but gravitationally bound orbit around 20,000 years ago.
The primary and secondary orbit every 104 days.
The primary star is a hot white Herbig Ae/Be star that has been variously assigned spectral types between B9 and A1. It has a surface temperature of 10,500 ± 500 K, is around 2.87 times as massive as the sun, 3 times its radius, and 100 times as luminous. It has a strong magnetic field which varies every 4.1 days and this is assumed to be the star's rotation period. Models show that the axis of rotation is inclined at 32 degrees. It is a variable star, considered an Orion variable, with occasional fading and other variability caused by obscuration from the surrounding dust. The apparent magnitude varies irregularly between 10.2 and 10.7. The properties of the star are calculated based on its maximum brightness, assumed to be the least obscured.
The secondary is a T Tauri star, detected by distinctive spectral lines that could not be produced by the hotter primary star, that has a surface temperature of 5,500 ± 500 K, is around 1.6 times as massive as the sun, twice its radius, and three times as luminous.
The nature of the tertiary component is uncertain. No spectral lines have been seen originating from this component.
The fourth star, sometimes called V380 Orionis B, is a small, cool object of spectral type M5 or M6 that is either a red dwarf or brown dwarf.

(Technical info excerpted from Wikipedia)


Picture: The Cosmic Keyhole detail, as seen in high definition by Hubble's Wide Field Planetary Camera on 24 October 2022. Credit: ESA/Hubble & NASA, ESO, K. Noll