Melotte 20 (Mel 20) - Alpha Persei (Mirfak) Cluster

Introduction | Map | Own Observations | References

On this page I collect my observations of the open star cluster Mel 20 (Alpha Persei/Mirfak Cluster) in the constellation Perseus.

Introduction

The open star cluster Mel 20 around the star Mirfak (Alpha Persei) in the constellation Perseus is regarded as a "star association" rather than a cluster. It is, however, not an arbitrary star pattern, because most of the stars of the association move in the same direction. The star cluster is quite large (3 degrees according to Stoyan), visible to the naked eye, very nice in binoculars, and already too big for a telescope.

Size: 3 ° (Stoyan)
Distance: 550 light years
Ranking: ** (Stoyan)

Map

The open star cluster Mel 20 is located around Mirfak (Alpha Persei, lowest red dot) in constellation Perseus (Image Courtesy of SkySafari Astronomy, www.simulationcurriculum.com)

Own Observations

Observations September 2017

In September 2017, I observed the open star cluster Mel 20 using the Heritage 100P at different magnifications, and particularly with binoculars (Sumène, Haute Loire, France):

Sep 21/22, 2017 (Sumène, Haute Loire, France: LT binoculars, Heritage 100P): Mel 20 seen beautifully with binoculars; also seen with 100P (24 mm) but not as nice...
Sep 29, 2017 (Sumène, Haute Loire, France: LT binoculars): Mel 20 seen with binoculars (half moon, milky way hard to see with the naked eye)

Observations October/November 2017

Oct 2017 (Mühlhausen/Kraichgau: LT, TS binoculars): Mel 20 seen with binoculars.
Nov 13, 2017 (ditto): Mel 20 seen with binoculars.

Observations January - Februar 2018

Jan 14, 2018 (Mühlhausen/Kraichgau: TS binoculars): Mel 20 observed with binoculars.
Feb 4-5, 2018 (ditto): Mel 20 observed with binoculars.
Feb 13, 2018 (ditto): Mel 20 observed with binoculars.
March 18-19, 2018 (Kellinghusen and Erkerode, TS binoculars): Mel 20 observed with binoculars.

Observations September- November 2018

Sep 19, 2018 (Sumène, Haute Loire, France: PS 72/432, AZ Pronto Mount, TS binoculars, OM21 binoculars): Mel 20 (Mirfak Cluster) seen well, particularly with the TS; acceptable with the PS72, less well with the OM21.
Sep 22, 2018 (Sumène, Haute Loire, France: PS 72/432, AZ Pronto Mount, TS binoculars): Mel 20 observed only briefly, because I looked for other objects.
Oct 4, 2018 (Sumène, Haute Loire, France: PS 72/432, AZ Pronto Mount): Mel 20 observed.
Oct 5, 2018 (Sumène, Haute Loire, France: TS binoculars, LT binoculars): Mel 20 observed.
Nov 1, 2018 (Mühlhausen/Kraichgau: TS binoculars): Mel 20 observed.
Nov 11, 2018 (Mühlhausen/Kraichgau: Heritage 100P, AZ Pronto Mount): Mel 20 observed.

Observations February 2019 ff

February 26, 2019 (Mühlhausen/Kraichgau: PS 72/432 on AZ Pronto Mount, Heritage 100P, TS binoculars): Mel 20 (Mirfak Cluster) observed (16 mm, probably also with 24 mm); seen in the TS binoculars. as well.
February 27, 2019 (Mühlhausen/Kraichgau: PS 72/432 on AZ Pronto Mount, TS binoculars): Mel 20 (Mirfak Cluster) observed with the TS binoculars.

Observations September to October 2019

September 17, 2019 (Sumène, France: OM21 binoculars): Mel 20 (Mirphak Cluster) seen as glow with OM21.
September 30, 2019 (Sumène, France: StarTravel 120/600 on AZ Pronto Mount): Mel 20 observed with the 35 mm ED eyepiece, very nice.
October 3, 2019 (Sumène, France: StarTravel 120/600 on AZ Pronto Mount): Mel 20 once more observed with the 35 mm ED eyepiece, very nice.

References

Alpha Persei Cluster (Wikipedia): https://en.wikipedia.org/wiki/Alpha_Persei_Cluster