Hemisphere:  Southern  ·  Constellation: Norma (Nor)  ·  Contains:  NGC 6164  ·  NGC 6165  ·  PK336-00.1
NGC-6164 in HOO-RGB, 


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NGC-6164 in HOO-RGB

NGC-6164 in HOO-RGB, 


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NGC-6164 in HOO-RGB

Acquisition details

May 10, 2020 ·  May 11, 2020 ·  May 12, 2020 ·  May 13, 2020 ·  May 14, 2020 ·  May 15, 2020
Chroma Technology Chroma Blue: 19×300(1h 35′) -20°C bin 1×1
Chroma Technology Chroma Green: 18×300(1h 30′) -20°C bin 1×1
Chroma Technology Chroma Ha 3nm: 66×1200(22h) -20°C bin 1×1
Chroma Technology Chroma OIII 3nm: 70×1200(23h 20′) -20°C bin 1×1
Chroma Technology Chroma R: 21×300(1h 45′) -20°C bin 1×1
Chroma Technology Chroma SII 3nm: 60×1200(20h) -20°C bin 1×1
70h 10′
Avg. Moon age:
20.61 days
Avg. Moon phase:
Bortle Dark-Sky Scale:

RA center: 16h33m43s.890

DEC center: -48°0531.67

Pixel scale: 0.732 arcsec/pixel

Orientation: -178.818 degrees

Field radius: 0.534 degrees

More info:Open 

Resolution: 3587x3834

File size: 63.8 MB

Data source: Own remote observatory

Remote source: Observatorio El Sauce


The system NGC6164-65 around star HD148937 is still being studied and everything still seems to be fixed...

NGC 6164 and NGC 6165 are the two brightest bulge of the bipolar nebula associated with HD 148937. The nebula is very probably related to faint concentric nebular arcs with radii of 13' and 45'-65' around that star. Superficially similar to a planetary nebula, NGC 6164-5 is in an unusual object associated with an unusual star. The amazing blue central star, known as HD 148937, is the brightest member of a triple system of stars in orbit around each other. This extremely hot star is losing mass from its outer layers continuously, but sometimes more powerful outbursts give rise to the symmetrical shell-like ejected nebula. The true age of the star is not known although estimates of its age vary from a pre-main sequence age of 350 000 years to a more evolved age of one to two million years. HD 148937 is a peculiar type of Of star with exotic emission lines (carbon emission lines (CIII) equal in strength to Nitrogen (NIII)) and other peculiar spectra indicative of significant mass loss. Only five such stars are known to exist, three in our galaxy and two in Small Magellanic Cloud. The two catalogue numbers, NGC 6164 and NGC 6165, refer to the nebula shells as separate objects. The nebula is in Norma at a distance of about 4 200 light years.

The magnetic star HD 148937 is the only Galactic Of?p star surrounded by a nebula. The structure of this nebula is particularly complex and is composed, from the center out outwards, of a close bipolar ejecta nebula (NGC 6164/5), an ellipsoidal wind-blown shell, and a spherically symmetric Strömgren sphere. The exact formation process of this nebula and its precise relation to the star's evolution remain unknown.

The Hα image displays a bipolar or "8"-shaped ionized nebula, whilst the infrared images show dust to be more concentrated around the central object. The combined analyses of the known kinematics and of the new abundances of the nebula suggest either a helical morphology for the nebula, possibly linked to the magnetic geometry, or the occurrence of a binary merger.

Three Galactic O-type stars belong to the rare class of Of?p objects: HD 108, HD 191612, and HD 148937. HD 148937 consists of two O-type stars with masses of approximately 34 and 49 M⊙.

Optical spectra have been obtained for the recently-discovered faint filamentary halo that surrounds both the extremely young star HD 148937 and the peculiar S-shaped nebula NGC 6164-65. This halo, interpreted to be a wind-generated interstellar bubble, has a spectrum which appears to result from both shock-wave heating and photoionization.


Sky plot

Sky plot


NGC-6164 in HOO-RGB,