Messier 57 (M57), also known as the Ring Nebula, is a well-known planetary nebula located in the northern constellation Lyra. The Ring Nebula has an apparent magnitude of 8.8 and lies at an approximate distance of 2,300 light years from Earth. It has the designation NGC 6720 in the New General Catalogue. Messier 57 lies… Read More »Messier 57: Ring Nebula| Messier Objects
Fornax (the Furnace) is a faint constellation in the southern sky. It is home to the Fornax Dwarf and the Fornax Cluster, which contains the Great Barred Spiral galaxy (NGC 1365) and Fornax A (NGC 1316).| www.constellation-guide.com
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Whether planetary nebulae (PNe) are predominantly the product of binary stellar evolution as some population synthesis models (PSM) suggest remains an open question. Around 50 short period binary central stars ($P\sim1$ d) are known, but with only four with measured orbital periods over 10 d, our knowledge is severely incomplete. Here we report on the first discovery from a systematic SALT HRS survey for long period binary central stars. We find a 142 d orbital period from radial velocities o...| arXiv.org
We reconsider calibration of statistical distance scales for planetary nebulae, examining precision and systematic error for various distance methods used as well as the scales themselves. A different calibration strategy, one based on precise trigonometric parallaxes by Harris et al. (2007; some improved by Benedict et al. 2009), is presented. Most statistical scales have an overall scale error; in addition, all four tested show dependence of distance ratio [scale/actual] on nebular radius. ...| arXiv.org
Dalim (α For) is the primary component in a triple star system located 45.66 light-years away. It is the brightest star in the southern constellation Fornax (the Furnace).| Star Facts
Eridanus is one of the largest constellations in the sky. It represents the celestial river. It is home to Achernar, one of the brightest stars in the sky, the nearby star Epsilon Eridani, and the Witch Head Nebula (IC 2118).| www.constellation-guide.com
Lyra is a small constellation in the northern sky. It represents the lyre of Orpheus. The constellation is home to Vega, the second brightest northern star, and the Ring Nebula (M57), a famous planetary nebula.| www.constellation-guide.com
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