Spirograph Nebula (IC 418)

IC 418
IC 418: Image taken with Hubble Space Telescope. © ESA/Hubble & NASA [540]

History

This planetary nebula was discovered on 26 March 1891 by Williamina Fleming, a Scottish-American astronomer. She worked for Edward Pickering to whom John L. E. Dreyer mistakenly credited the discovery in his «Index Catalogue» appeared in 1895. [314]

Physical Properties

IC 418 is a planetary nebula with a high-density ellipsoidal shell, which overall morphology looks simple. A detailed view of the Hubble Space Telescope has revealed an intricate cyclic pattern that has given the «Spirograph Nebula». Magnetic fields or variable stellar wind could be responsible for these patterns. The central star has a relatively low effective temperature of 39'000 K and is in an early evolutionary stage. The distance is measured to 1.3 ± 0.4 kpc. [541]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
DesignationsPN G215.2-24.2: IC 418, PK 215-24.1, ARO 3, VV 22, VV' 32
Right Ascension (J2000.0)05h 27m 28s
Declination (J2000.0)-12° 41' 48"
Dimensions 12." (optical)
Distance 0.88 kpc
Radial Velocity+61.0 km/s ± 2.0 km/s
Expansion Velocity< 6.0 km/s (O-III), 12. km/s (N-II)
C-Star DesignationsAG82 43, BD -12 1172, EM* CDS 500, GCRV 3288, HD 35914, PLX 1239, TD1 4662
C-Star Magnitude10.00 mag (B filter), 10.17 mag (V filter)
C-Star Spectral TypeOf(H)
DiscovererFLEMING 1891

Finder Chart

The 10 mag star ZZ Leporis with the planetary nebula IC 418 is located near the ears of the Hare (Lepus), south of Orion. Together with three other stars of about 7 mag it forms a conspicuous figure that can be seen in an eyepiece which gives approximately 1° true field of view. The best time to observe it is November to January.

Chart Spirograph Nebula (IC 418)
Spirograph Nebula (IC 418) in constellation Lepus. Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

More Objects Nearby (±15°)

References

141Strasbourg-ESO Catalogue of Galactic Planetary Nebulae; A. Acker, F. Ochsenbein, B. Stenholm, R. Tylenda, J. Marcout, C. Schohn; European Southern Observatory; ISBN 3-923524-41-2 (1992); cdsarc.unistra.fr/viz-bin/cat/V/84 (2021-02-18)
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
314«Index Catalogue of Nebulæ found in the years 1888 to 1894, with Notes and Corrections to the New General Catalogue» Dreyer, J. L. E.; Memoirs of the Royal Astronomical Society, Vol. 51, p.185; 1895; Bibcode:1895MmRAS..51..185D
540The Spirograph Nebula; esahubble.org/images/opo0028a (2022-09-30)
541«Discovery of multiple shells around the planetary nebula IC 418» G. Ramos-Larios, R. Vázquez, M. A. Guerrero, L. Olguín, R. A. Marquez-Lugo, H. Bravo-Alfaro; Monthly Notices of the Royal Astronomical Society, Volume 423, Issue 4, July 2012, Pages 3753–3760; DOI:10.1111/j.1365-2966.2012.21165.x