Planetary Nebula Haro 3-75

Haro 3-75
Haro 3-75: Planetary nebula in Orion; 500 mm Cassegrain 3625 mm f/7.2, SBIG STL11K; 120+40+40+40 min LRGB; Bernese Highlands; © 2015 Radek Chromik [32]


In 1953, the Mexican astronomer Guillermo Haro Barraza examined the Taurus-Auriga-Orion region with the 64 cm Schmidt camera at the Tonantzintla Observatory in Mexico. Previously, Alfred Harrison Joy at the Mount Wilson Observatory had discovered numerous stars with strong Hα emission lines, so-called T-Tauri stars. These are young stars that are uneven from a disk of dust. Haro discovered 75 more Hα stars on the photo plates exposed for up to 90 minutes. To number 75 he added the following note: «Strange object. The star is surrounded by a halo that shows emissions in Hα, N1, N2 and possibly other bright lines on images.» [451] The American astronomer Nicholas Ulrich Mayall finally recognized in 1964 that this was a planetary nebula. [144]

Physical Properties

On Simbad one finds a parallax of 0.2308 mas (milli-arcseconds), which corresponds to a distance of about 4.3 kpc (about 14'000 light years). The apparent brightness in different bands is: B = 14.8 mag, G = 13.8 mag, J = 12.0 mag, H = 11.5 mag, K = 11.3 mag. [145]

«Strasbourg-ESO Catalogue of Galactic Planetary Nebulae» Acker et al., 1992 [141]
Designations PN G193.6-09.5: H 3-75, PK 193-09.1, ARO 218
Right Ascension (J2000.0) 05h 40m 44s
Declination (J2000.0) +12° 21' 17"
Dimensions 24." (optical)
Radial Velocity +9.5 ± 19.0 km/s
Discoverer MAYALL 1964

Finder Chart

The planetary nebula Haro 3-75 is located in the constellation Orion. The best observation time is September to March.

Finder Chart Planetary Nebula Haro 3-75
Planetary Nebula Haro 3-75 in constellation Orion. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°