| Reflection nebula | |
|---|---|
_(potm2408b).jpg) | |
| Observation data: J2000.0epoch | |
| Right ascension | 03h 29m 11.3s[1] |
| Declination | +31° 18′ 36″[1] |
| Distance | 967 ly (296.5 pc)[1] ly |
| Apparent magnitude (V) | 5.6 |
| Apparent dimensions (V) | 6′ x 3′ |
| Constellation | Perseus |
| Designations | Ced 16, GN 03.26.1, LBN 741[2] |
| See also:Lists of nebulae | |
NGC 1333 is areflection nebula located in the northernconstellationPerseus, positioned next to the southern constellation border withTaurus andAries.[3] It was first discovered by German astronomerEduard Schönfeld in 1855.[4] The nebula is visible as a hazy patch in a small telescope, while a larger aperture will show a pair of dark nebulae designated Barnard 1 and Barnard 2.[5] It is associated with a dark cloud L1450 (Barnard 205). Estimates of the distance to this nebula range from 980–1,140 ly (300–350 pc).[4]
This nebula is in the western part[4] of thePerseus molecular cloud and is a young region of very active star formation,[6] being one of the best-studied objects of its type.[4] It contains a fairly typical hierarchy ofstar clusters that are still embedded in themolecular cloud in which they formed,[7] which are split into two main sub-groups to the north and south. Most of theinfrared emission is happening in the southern part of the nebula. A significant portion of the stars seen in the infrared are in thepre-main sequence stage of theirevolution.[6]
The nebula region has a combined mass of approximately450 M☉,[4] while the cluster contains around 150 stars with a median age of a million years and a combined mass of100 M☉. The average star formation rate is1×10−4 M☉ yr–1.[4] Within the nebula are 20young stellar objects producing outflows, includingHerbig–Haro objects, and a total of 95 X-ray sources that are associated with known members of embedded star clusters.[6] In 2011 researchers reported finding 30 to 40brown dwarf objects in the cloud and in theRho Ophiuchi cloud complex.[8]
15 objects with a spectral type ofM9 or later were discovered in NGC 1333. This spectral type corresponds to a mass of aplanetary-mass object (PMO) at the age of NGC 1333. About 42% of the PMO are surrounded by a circumstellar disk, but only one out of six objects with a spectral type ofL0 (about 10MJ) or later has a disk. Scholz et al. argues that this indicates that very low mass PMOs form like planets (akaejected planets) and not like stars (also calledsub-brown dwarfs).[9] Parker & Alves de Oliveira on the other hand argue that the distribution of PMOs in NGC 1333 followsN-body simulations of objects that form like stars and that none of the PMOs has a peculiarmotion, which is predicted for ejected planets. They also note that ejected planets are hiding in this and other star-forming regions.[10] Additional PMOs were discovered by Scholz et al. 2012 withSubaru (e.g.SONYC-NGC1333-36 with estimated 6MJ)[11] and by Langeveld et al. 2024 withJWST (6 objects and oneJuMBO candidate). Langeveld et al. did not find any object below 4MJ, despite JWST being sensitive enough to detect these objects. This could mean that star-formation does not occur below 4MJ, which is consistent with previous observations in most star-forming regions and the nearby stellar population. One source, calledNIRISS-NGC1333-5 (NN5), shows infrared excess, which is an indication of adisk around the object. With a mass of 5MJ, this object could be one of the lowest mass object with a disk known so far.[12]
![A small region of NGC 1333 taken by Hubble Space Telescope.[13] The bi-polar object in the upper part is HH 4](/mt/?noimg=&dark=on&url=http%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aNGC_1333_Champions_League.jpg)
![There are 5 Herbig–Haro objects (numbered 7 to 11) in this image, which are located in the southern part of NGC 1333.[14]](/mt/?noimg=&dark=on&url=http%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aThe_smoking_gun_of_a_newborn_star.jpg)
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