A Hubble Space Telescope (HST) image of NGC 6818. Credit: HST/NASA/ESA.
Observation data: J2000 epoch
Right ascension
19h 43m 57.8s[1]
Declination
−14° 9′ 11.9″[1]
Apparent magnitude (V)
10
Apparent dimensions (V)
22" x 15"
Constellation
Sagittarius
Physical characteristics
Radius
0.32 ly
Designations
PK 25-17.1, HD 186282, GCRV 12096, BD-14 5523
See also: Lists of nebulae
The Little Gem Nebula or NGC 6818 is a planetary nebula located in the constellation of Sagittarius. It has magnitude 10 and oval diameter of 15 to 22 arcseconds with a 15th magnitude central star.
It was discovered by William Herschel in 1787.
NGC 6818 is located in the constellation of Sagittarius (The Archer), roughly 6000 light-years away from Earth. The glow of the cloud is just over half a light-year across.
When stars like the Sun are near end of life, they send their outer layers into space to create glowing clouds of gas, a planetary nebulae. This ejection of mass is uneven, and planetary nebulae can have complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud.
Scientists believe that the stellar wind from the central star propels the outflowing material, forming the elongated shape of NGC 6818. As this stellar wind moves through the slower-moving cloud it creates particularly bright spots in the bubble's outer layers.[2]
^ ab"SIMBAD Astronomical Database". Results for NGC 6818. Retrieved 2007-04-23.
^"Hubble Finds a Little Gem". NASA. 7 August 2015. Retrieved 2015-08-07.
The Little Gem Nebula or NGC6818 is a planetary nebula located in the constellation of Sagittarius. It has magnitude 10 and oval diameter of 15 to 22...
Pottasch, S. R.; et al. (June 2005), "Abundances of planetary nebulae NGC 2022, NGC6818 and IC 4191", Astronomy and Astrophysics, 436 (3): 953–965, Bibcode:2005A&A...
the NGC 4111 group are the galaxies UGC 6818, NGC 3938, NGC 4013, IC 749, IC 750, NGC 4051, UGC 7089, UGC 7094, NGC 4117, NGC 4138 and NGC 4183. NGC 4111...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
II Program. The catalogue contains 400 objects. All objects are from the NGC. All objects are visible in mid northern latitudes, since they were all observed...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGC 6782 is a barred spiral galaxy located in the southern constellation of Pavo, at a distance of approximately 173 megalight-years from the Milky Way...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...
NGCNGC 6440 NGC 6520 NGC 6522 NGC 6528 NGC 6530 NGC 6540 NGC 6544 NGC 6553 NGC 6558 NGC 6569 NGC 6603 NGC 6624 NGC 6638 NGC 6642 NGC 6717 NGC 6723 Other...