Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
NGC 300
NGC 300 (also known as Caldwell 70 or the Sculptor Pinwheel Galaxy) is a spiral galaxy in the constellation Sculptor. It was discovered on 5 August 1826 by Scottish astronomer James Dunlop. It is one of the closest galaxies to the Local Group, and it most likely lies between the latter and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group. It is inclined at an angle of 42° when viewed from Earth and shares many characteristics of the Triangulum Galaxy. It is about 94,000 light-years in diameter, somewhat smaller than the Milky Way, and has an estimated mass of (2.9 ± 0.2) × 1010 M☉.
NGC 300 and the Magellanic type barred spiral galaxy NGC 55 have traditionally been identified as members of the Sculptor Group, a nearby group of galaxies in the constellation of the same name. However, recent distance measurements indicate that these two galaxies actually lie in the foreground. It is likely that NGC 300 and NGC 55 form a gravitationally bound pair.
The dwarf galaxy Sculptor C is located about 6.65 million light-years (2.04 megaparsecs) away from the Sun, and is very likely a satellite galaxy of NGC 300. Sculptor C has an absolute magnitude of about −9.1 which is typical for other recently discovered ultra-faint dwarf galaxies.
In 1986, Allan Sandage estimated the distance to NGC 300 to be 5.41 Mly (1.66 Mpc). By 1992, this had been updated to 6.9 Mly (2.1 Mpc) by Freedman et al. In 2006, this was revised by Karachentsev et al. to be 7.0±0.3 Mly (2.15±0.10 Mpc). At about the same time, the tip of the red giant branch (TRGB) method was used to produce an estimate of 5.9±0.4 Mly (1.82±0.13 Mpc) using edge detection and 6.1±0.4 Mly (1.87±0.12 Mpc) using maximum likelihood. These results were consistent with estimates using near-infrared photometry of Cepheid variables by Gieren et al. 2005 that provided an estimate of 6.1±0.2 Mly (1.88±0.07 Mpc). Combining the recent TRGB and Cepheid estimates the distance to NGC 300 is estimated at 6.07±0.23 Mly (1.86±0.07 Mpc).[a]
On a CCD image obtained on 14 May 2008, amateur astronomer L.A.G. Berto Monard discovered a bright optical transient (OT) in NGC 300 that is designated NGC 300-OT. It is located at RA: 00h 54m 34.552s and DEC: −37° 38′ 31.79″ in a spiral arm containing active star formation. Its broad-band magnitude was 14.3 in that image. An earlier image (from 24 April 2008), taken just after NGC 300 reemerged from behind the Sun, evidenced an already brightening OT at ~16.3 magnitude. No brightening was detected on a 8 February 2008 image, nor on any earlier ones. The transient's peak measured magnitude was 14.69 on 15 May 2008.
At discovery, the transient had an absolute magnitude of MV ≈ −13, making it faint in comparison to a typical core-collapse supernova but bright in comparison to a classical nova. Additionally, the photometric and spectroscopic properties of the OT imply that it is not a luminous blue variable either. Since its peak, brightness dropped smoothly through September 2008 while becoming continuously redder. After September 2008, brightness continued to fall at a lower rate in the optical spectrum but with strong Hα emissions. Further, the optical spectrum is mostly made up of fairly narrow Hydrogen Balmer and Ca II emission lines coupled with strong Ca II H&K absorption. Research into historical Hubble images provide an accurate upper bound on the progenitor star's brightness. This suggested a low-mass main sequence star as progenitor with the transient resulting from a stellar merger similar to red Galactic nova V838 Monocerotis. Analysis of historical images of the area of the OT suggest with 70% certainty that the progenitor formed in a burst of stars around 8–13 Myr ago and implies the progenitor's mass to be 12–25 M⊙ assuming the OT is due to an evolving massive star.
However, in 2008 a bright mid-infrared progenitor to the transient was discovered in historical Spitzer data. This was a star that was obscured by dust, with energy distribution analogous to a black-body of R ≈ 300 AU and radiating at T ≈ 300 K with Lbol ≈ ×106 L⊙. This demonstrated that the transient was associated with an energetic explosion of a low-mass ≈ 10 M⊙ star. The transient's low luminosity as compared to typical core-collapse supernova, combined with its spectral attributes and dust covered properties, make it nearly identical to NGG 6946's SN 2008S.
The spectrum of NGC 300-OT observed with Spitzer shows strong, broad emission features at 8 μm and 12 μm. Such features are also seen in Galactic carbon-rich protoplanetary nebulae.
Hub AI
NGC 300 AI simulator
(@NGC 300_simulator)
NGC 300
NGC 300 (also known as Caldwell 70 or the Sculptor Pinwheel Galaxy) is a spiral galaxy in the constellation Sculptor. It was discovered on 5 August 1826 by Scottish astronomer James Dunlop. It is one of the closest galaxies to the Local Group, and it most likely lies between the latter and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group. It is inclined at an angle of 42° when viewed from Earth and shares many characteristics of the Triangulum Galaxy. It is about 94,000 light-years in diameter, somewhat smaller than the Milky Way, and has an estimated mass of (2.9 ± 0.2) × 1010 M☉.
NGC 300 and the Magellanic type barred spiral galaxy NGC 55 have traditionally been identified as members of the Sculptor Group, a nearby group of galaxies in the constellation of the same name. However, recent distance measurements indicate that these two galaxies actually lie in the foreground. It is likely that NGC 300 and NGC 55 form a gravitationally bound pair.
The dwarf galaxy Sculptor C is located about 6.65 million light-years (2.04 megaparsecs) away from the Sun, and is very likely a satellite galaxy of NGC 300. Sculptor C has an absolute magnitude of about −9.1 which is typical for other recently discovered ultra-faint dwarf galaxies.
In 1986, Allan Sandage estimated the distance to NGC 300 to be 5.41 Mly (1.66 Mpc). By 1992, this had been updated to 6.9 Mly (2.1 Mpc) by Freedman et al. In 2006, this was revised by Karachentsev et al. to be 7.0±0.3 Mly (2.15±0.10 Mpc). At about the same time, the tip of the red giant branch (TRGB) method was used to produce an estimate of 5.9±0.4 Mly (1.82±0.13 Mpc) using edge detection and 6.1±0.4 Mly (1.87±0.12 Mpc) using maximum likelihood. These results were consistent with estimates using near-infrared photometry of Cepheid variables by Gieren et al. 2005 that provided an estimate of 6.1±0.2 Mly (1.88±0.07 Mpc). Combining the recent TRGB and Cepheid estimates the distance to NGC 300 is estimated at 6.07±0.23 Mly (1.86±0.07 Mpc).[a]
On a CCD image obtained on 14 May 2008, amateur astronomer L.A.G. Berto Monard discovered a bright optical transient (OT) in NGC 300 that is designated NGC 300-OT. It is located at RA: 00h 54m 34.552s and DEC: −37° 38′ 31.79″ in a spiral arm containing active star formation. Its broad-band magnitude was 14.3 in that image. An earlier image (from 24 April 2008), taken just after NGC 300 reemerged from behind the Sun, evidenced an already brightening OT at ~16.3 magnitude. No brightening was detected on a 8 February 2008 image, nor on any earlier ones. The transient's peak measured magnitude was 14.69 on 15 May 2008.
At discovery, the transient had an absolute magnitude of MV ≈ −13, making it faint in comparison to a typical core-collapse supernova but bright in comparison to a classical nova. Additionally, the photometric and spectroscopic properties of the OT imply that it is not a luminous blue variable either. Since its peak, brightness dropped smoothly through September 2008 while becoming continuously redder. After September 2008, brightness continued to fall at a lower rate in the optical spectrum but with strong Hα emissions. Further, the optical spectrum is mostly made up of fairly narrow Hydrogen Balmer and Ca II emission lines coupled with strong Ca II H&K absorption. Research into historical Hubble images provide an accurate upper bound on the progenitor star's brightness. This suggested a low-mass main sequence star as progenitor with the transient resulting from a stellar merger similar to red Galactic nova V838 Monocerotis. Analysis of historical images of the area of the OT suggest with 70% certainty that the progenitor formed in a burst of stars around 8–13 Myr ago and implies the progenitor's mass to be 12–25 M⊙ assuming the OT is due to an evolving massive star.
However, in 2008 a bright mid-infrared progenitor to the transient was discovered in historical Spitzer data. This was a star that was obscured by dust, with energy distribution analogous to a black-body of R ≈ 300 AU and radiating at T ≈ 300 K with Lbol ≈ ×106 L⊙. This demonstrated that the transient was associated with an energetic explosion of a low-mass ≈ 10 M⊙ star. The transient's low luminosity as compared to typical core-collapse supernova, combined with its spectral attributes and dust covered properties, make it nearly identical to NGG 6946's SN 2008S.
The spectrum of NGC 300-OT observed with Spitzer shows strong, broad emission features at 8 μm and 12 μm. Such features are also seen in Galactic carbon-rich protoplanetary nebulae.