Mz 1 (Menzel 1), is a bipolar

planetary nebula A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to planets. The ...

(PN) in the constellation

Norma Norma may refer to: * Norma (given name), a given name (including a list of people with the name) ** Norma Lizbeth Ramos, a Mexican bullying victim Astronomy *Norma (constellation) * 555 Norma, a minor asteroid * Cygnus Arm or Norma Arm, a spiral ...

Characteristics

Menzel 1 is a bright planetary nebula that has a prominent central ring of enhanced emission. One model of its structure is a three-dimensional

hour-glass An hourglass (or sandglass, sand timer, or sand clock) is a device used to measure the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) from the ...

shape with a smoothly decreasing density starting from the waist or equator as measured outwardly to the poles. It is radially expanding at a rate of about 23 km/s and estimated to be around 4,500 to 10,000 years old and has its polar axis oriented at an angle of around 40° from the plane of the sky. Its central star is estimated to have a mass of . In 1992 Schwarz, Corradi, & Melnick published narrow band images of Mz 1 in H''α'' and III H₂ emission was observed in Mz 1 by Webster, Payne, Storey, Dopita (1988). However, despite its relative brightness, Mz 1 has only been studied in a few papers .

History

Mz 1 was discovered by

Donald Howard Menzel Donald Howard Menzel (April 11, 1901 – December 14, 1976) was one of the first theoretical astronomers and astrophysicists in the United States. He discovered the physical properties of the solar chromosphere, the chemistry of stars, the atmosp ...

in 1922.

Notes

3,400 ± 500 ly distance × sin( 76 diameter_angle / 2 ) = 0.63 ± 0.09 ly. radius
12.0 apparent magnitude - 5 * (log₁₀(1,050 ± 150 pc distance) - 1) = 1.9 ± 0.3 absolute magnitude

References

* (archive) * * *

External links

* http://www.astro.washington.edu/users/balick/PNIC/PNimages_by_galcoord/322.4-02.6.Mz1.jpg {{DEFAULTSORT:Mz 1 Planetary nebulae Norma (constellation) ?