The Becklin–Neugebauer Object(BN) is an object visible only in the
infrared in the Orion molecular cloud 1 (OMC1). It was discovered in 1967 by
Eric Becklin and
Gerry Neugebauer during their
near-infrared survey of the
Orion Nebula.[4] A faint glow around the center-most stars can be observed in the visible light spectrum, especially with the aid of a telescope.
The BN Object is thought to be an intermediate-mass
protostar. It was the first star detected using infrared methods and is deeply embedded within the Orion
star-formingnebula, where it is invisible at optical wavelengths because the light is completely scattered or absorbed due to the high density of dusty material.
BN moves towards the northwest with respect to other stars in the
Kleinmann-Low nebula. A
proper motion of between 21 and 27 km/s in the northwest region and a redshift of about 11 km/s with respect to the OMC1 was measured for this star. BN is therefore considered a
runaway star.[7]
It was proposed that
Theta1Ori C ejected BN about 4000 years ago, but it is more likely that BN and two other runaway stars, called Source I (Src I) and Source n (Src n), were ejected from a position about 500 years ago. Source I and Source n both move in opposite directions, away from BN.[7]
With more recent
VLA proper motion measurements it was realised that at least six compact sources recede from a common point: BN, source I, Orion MR (formerly source n), X, IRc23 and Zapata 11. Almost all these sources were ejected about 500 years ago.[8] The ejection of BN and source I was proposed to have occurred in the year
1475±6 (about 550 years ago).[9] IRc23 was ejected only 300 years ago.[8]
At the time of the ejection four or more protostars dynamically interacted with each other, leading to the ejection of the stars in different directions. In the classical
three-body scenario, the dynamical interaction either formed a
compact binary or the
merger of two stars.[7] The large number of ejected stars suggest a more complex interaction, such as the interaction of a tight binary with a compact
star cluster.[8]
This dynamical interaction released a large amount of energy, causing an infrared-only flare on the scale of a
nova or
supernova with an energy of about 1048erg.[7]
Alternatively the explosion was not a multi-system interaction but a supernova.[10]
The remnant of the explosion is called
Kleinmann-Low nebula.[11] Multi-wavelength observations and
carbon monoxide (CO) observations with
ALMA reveal the mostly spherical remnant of an explosion at the intersection point of the BN object and Source I. The ALMA observations revealed hundreds of CO streamers moving with up to 100 km/s. Some of these CO streamers nearly reach the shocked gas and dust observed in
molecular hydrogen and
iron [Fe II].[7]
Becklin's star
Becklin's star (IRC -10093) is located at 5h 35.3m / -5° 23', very near the Becklin-Neugebauer object.[12]
Gallery
The BN object (bright star in the center) in near-infrared with
ESO HAWKI.
Near-infrared view of the central region of the
Orion Nebula. In the center is the
Trapezium cluster and the red region above contains the BN object.
Complete view of the ALMA,
Gemini and
VLT image showing the explosion remnant. The stars in the lower-left are the Trapezium cluster.
Part of the explosion (fingers) in the northern/northwestern part with Gemini. Iron is blue and molecular hydrogen is orange in this image.
Jiang, Zhibo; Tamura, Motohide; Fukagawa, Misato; Hough, Jim; Lucas, Phil; Suto, Hiroshi; Ishii, Miki; Yang, Ji (2005). "A circumstellar disk associated with a massive protostellar object". Nature. 437 (7055): 112–115.
Bibcode:
2005Natur.437..112J.
doi:
10.1038/nature04012.
PMID16136137.
S2CID4424229.
Plambeck, R.L.; Bolatto, A. D.; Carpenter, J. M.; Eisner, J. A.; Lamb, J. W.; Leitch, E. M.; Marrone, D. P.; Muchovej, S. J.; Pérez, L. M.; Pound, M. W.; Teuben, P. J.; Volgenau, N. H.; Woody, D. P.; Wright, M. C. H.; Zauderer, B. A. (2013). "The Ionized Circumstellar Envelopes of Orion Source I and the Becklin-Neugebauer Object". The Astrophysical Journal. 765 (1): 40.
arXiv:1211.0085.
Bibcode:
2013ApJ...765...40P.
doi:
10.1088/0004-637X/765/1/40.
S2CID28627671.