Elias 2-27 (2MASS J16264502-2423077)
[ is a YSO ]star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...
[ with a ]protoplanetary disk
A protoplanetary disk is a rotating circumstellar disc of dense gas and dust surrounding a young newly formed star, a T Tauri star, or Herbig Ae/Be star. The protoplanetary disk may not be considered an accretion disk; while the two are sim ...
around it, located in the Ophiuchus Molecular Cloud
Ophiuchus () is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek (), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellati ...
(ρ Oph Cld, 5 Oph Cld, Ophiuchus Dark Cloud), a star-forming region in the Ophiuchus constellation, some away. This star system became the first ever observed with density wave
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be use ...
s in the disk, giving it a spiral structure. Elias 2-27 is located near the double star Rho Ophiuchi
Rho Ophiuchi (ρ Ophiuchi) is a multiple star system in the constellation Ophiuchus. The central system has an apparent magnitude of 4.63. Based on the central system's parallax, it is located about 450 light-years distant. The othe ...
(5 Ophiuchi).
Disk
In 2016, it was discovered that disk perturbations from density waves organized the disk debris into a pinwheel structure, with sweeping spiral arms; using observations from the Atacama Large Millimeter Array
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The ar ...
(ALMA) radio telescope. This marks the first instance of such an observation in a protoplanetary disk, though they have been previously predicted. The spiral arms start at and extend out to .[ The disk has a 14 AU wide gap at 69 AU radius with a reduced amount of dust.]
Further reading
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References
{{Stars of Ophiuchus
Ophiuchus
M-type stars
Pre-main-sequence stars
Circumstellar disks
J16264502-2423077