NGC 6781 - Misplaced Pages

Planetary nebula in the constellation Aquila

NGC 6781
Emission nebula
Planetary nebula
NGC 6781 from the La Silla Observatory
Observation data: J2000 epoch
Right ascension	19 18 28.085
Declination	+06° 32′ 19.29″
Distance	1,500 ly (460 pc)
Apparent magnitude (V)	11.4
Apparent dimensions (V)	1′.9 × 1′.8
Constellation	Aquila
Physical characteristics
Radius	0.44 ly

Designations	IRAS 19160+0626, NGC 6781
See also: Lists of nebulae

NGC 6781, also known as the Snowglobe Nebula, is a planetary nebula located in the equatorial constellation of Aquila, about 2.5° east-northeast of the 5th magnitude star 19 Aquilae. It was discovered July 30, 1788 by the Anglo-German astronomer William Herschel. The nebula lies at a distance of 1,500 ly from the Sun. It has a visual magnitude of 11.4 and spans an angular size of 1.9 × 1.8 arcminutes.

The bipolar dust shell of this nebula is believed to be barrel-shaped and is being viewed from nearly pole-on. It has an outer angular radius of 61″; equivalent to a physical radius of 0.44 ly (0.135 pc). The total mass of gas ejected as the central star passed through its last asymptotic giant branch (AGB) thermal pulse event is 0.41 M_☉, while the estimated dust mass is 1.53 M_☉.

The magnitude 16.88 central star of the planetary nebula is a white dwarf with a spectral type of DAO. It has an M-type co-moving companion at a projected separation of under 5,000 AU. The white dwarf progenitor star had an estimated initial mass of ~2.5 M_☉. It left the AGB and entered the cooling stage around 9,400 years ago.

References

^ Kerber, F.; et al. (September 2003). "Galactic Planetary Nebulae and their central stars. I. An accurate and homogeneous set of coordinates". Astronomy and Astrophysics. 408 (3): 1029–1035. Bibcode:2003A&A...408.1029K. doi:10.1051/0004-6361:20031046.
^ Otsuka, Masaaki; et al. (August 2017). "The Herschel Planetary Nebula Survey (HerPlaNS): A Comprehensive Dusty Photoionization Model of NGC6781". The Astrophysical Journal Supplement Series. 231 (2): 29. arXiv:1707.06565. Bibcode:2017ApJS..231...22O. doi:10.3847/1538-4365/aa8175. PMC 5619666. PMID 28966408. 22.
^ O'Meara, Steve (2007). Herschel 400 Observing Guide. Cambridge University Press. p. 249. ISBN 9780521858939.
"NGC 6781". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2007-04-18.
Stoyan, Ronald; Schurig, Stephan (2014). interstellarum Deep Sky Atlas. Erlangen: Cambridge University Press; Oculum-Verlag GmbH. ISBN 978-1-107-50338-0. OCLC 920437579.
Seligman, Courtney. "NGC Objects: NGC 6750 - 6799". Celestial Atlas. Retrieved 2021-01-07.
Phillips, J. P.; et al. (July 2011). "Optical and mid-infrared observations of the planetary nebula NGC 6781". Monthly Notices of the Royal Astronomical Society. 415 (1): 513–524. arXiv:1106.3706. Bibcode:2011MNRAS.415..513P. doi:10.1111/j.1365-2966.2011.18722.x. S2CID 119269567.
González-Santamaría, I.; et al. (2021). "Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity". Astronomy & Astrophysics. 656: A51. arXiv:2109.12114. Bibcode:2021A&A...656A..51G. doi:10.1051/0004-6361/202141916. S2CID 237940344.

External links

Media related to NGC 6781 at Wikimedia Commons
NGC 6781 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

v t e New General Catalogue 6500 to 6999
6500 6501 6502 6503 6504 6505 6506 6507 6508 6509 6510 6511 6512 6513 6514 6515 6516 6517 6518 6519 6520 6521 6522 6523 6524 6525 6526 6527 6528 6529 6530 6531 6532 6533 6534 6535 6536 6537 6538 6539 6540 6541 6542 6543 6544 6545 6546 6547 6548 6549 6550 6551 6552 6553 6554 6555 6556 6557 6558 6559 6560 6561 6562 6563 6564 6565 6566 6567 6568 6569 6570 6571 6572 6573 6574 6575 6576 6577 6578 6579 6580 6581 6582 6583 6584 6585 6586 6587 6588 6589 6590 6591 6592 6593 6594 6595 6596 6597 6598 6599 6600 6601 6602 6603 6604 6605 6606 6607 6608 6609 6610 6611 6612 6613 6614 6615 6616 6617 6618 6619 6620 6621 6622 6623 6624 6625 6626 6627 6628 6629 6630 6631 6632 6633 6634 6635 6636 6637 6638 6639 6640 6641 6642 6643 6644 6645 6646 6647 6648 6649 6650 6651 6652 6653 6654 6655 6656 6657 6658 6659 6660 6661 6662 6663 6664 6665 6666 6667 6668 6669 6670 6671 6672 6673 6674 6675 6676 6677 6678 6679 6680 6681 6682 6683 6684 6685 6686 6687 6688 6689 6690 6691 6692 6693 6694 6695 6696 6697 6698 6699 6700 6701 6702 6703 6704 6705 6706 6707 6708 6709 6710 6711 6712 6713 6714 6715 6716 6717 6718 6719 6720 6721 6722 6723 6724 6725 6726 6727 6728 6729 6730 6731 6732 6733 6734 6735 6736 6737 6738 6739 6740 6741 6742 6743 6744 6745 6746 6747 6748 6749 6750 6751 6752 6753 6754 6755 6756 6757 6758 6759 6760 6761 6762 6763 6764 6765 6766 6767 6768 6769 6770 6771 6772 6773 6774 6775 6776 6777 6778 6779 6780 6781 6782 6783 6784 6785 6786 6787 6788 6789 6790 6791 6792 6793 6794 6795 6796 6797 6798 6799 6800 6801 6802 6803 6804 6805 6806 6807 6808 6809 6810 6811 6812 6813 6814 6815 6816 6817 6818 6819 6820 6821 6822 6823 6824 6825 6826 6827 6828 6829 6830 6831 6832 6833 6834 6835 6836 6837 6838 6839 6840 6841 6842 6843 6844 6845 6846 6847 6848 6849 6850 6851 6852 6853 6854 6855 6856 6857 6858 6859 6860 6861 6862 6863 6864 6865 6866 6867 6868 6869 6870 6871 6872 6873 6874 6875 6876 6877 6878 6879 6880 6881 6882 6883 6884 6885 6886 6887 6888 6889 6890 6891 6892 6893 6894 6895 6896 6897 6898 6899 6900 6901 6902 6903 6904 6905 6906 6907 6908 6909 6910 6911 6912 6913 6914 6915 6916 6917 6918 6919 6920 6921 6922 6923 6924 6925 6926 6927 6928 6929 6930 6931 6932 6933 6934 6935 6936 6937 6938 6939 6940 6941 6942 6943 6944 6945 6946 6947 6948 6949 6950 6951 6952 6953 6954 6955 6956 6957 6958 6959 6960 6961 6962 6963 6964 6965 6966 6967 6968 6969 6970 6971 6972 6973 6974 6975 6976 6977 6978 6979 6980 6981 6982 6983 6984 6985 6986 6987 6988 6989 6990 6991 6992 6993 6994 6995 6996 6997 6998 6999
Astronomical catalog List of NGC objects 6001–7000

New General Catalogue 6500 to 6999

Constellation of Aquila

Stars

Bayer	α (Altair) β (Alshain) γ (Tarazed) δ ε ζ (Okab) η θ (Tseen Foo) ι κ λ μ ν ξ (Libertas) ο π σ τ υ φ χ ψ ω ω A b c d e f g h i k l
Flamsteed	4 5 7 8 10 11 18 19 20 21 22 23 24 42 45 46 51 56 57 58 62 64 66 68 69 70 14 Sge 62 Ser 64 Sgr
Variable	R U V W TT FF QS V368 V450 V500 V603 V604 V605 V606 V923 V1286 V1291 V1298 V1302 V1315 V1333 V1339 V1427 V1428 V1429 V1472 V1487 V1494 V1654 V1672 V1691 V1703 (Phoenicia) V1828 V1936
HR	7099 7143 7288 7300 7307 7396 7456 7569 7598 7599 7693 7717 7803
HD	179079 183263 187734 192699 (Chechia)
Other	CoRoT-2 CoRoT-3 CoRoT-8 Gaia BH3 HAT-P-41 PSR J1856+0245 PSR J1903+0327 PSR B1913+16 (Hulse–Taylor) PSR J1951+1123 SGR 1900+14 SS 433 W43A W49-2 WASP-80 (Petra) WD J1953−1019 ZTF J1901+1458

Exoplanets	CoRoT-2b CoRoT-3b CoRoT-8b CoRoT-10b HD 179079 b HD 183263 b c HD 192263 b HD 192699 b ξ Aquilae b

Star clusters	NGC 6709 NGC 6738 NGC 6755 NGC 6756 NGC 6760

Nebulae

NGC	6741 6751 6778 6781 6790
Other	Abell 48 Abell 70 E Nebula Hen 2-428 HESS J1857+026 W43 W49 W49B W50

Galaxies

NGC	6814
Other	IC 1327