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37 Cluster

Updated: Jan 20


About this object


NGC 2169 is a young open cluster in the Orion constellation that is roughly 10 million years old. NGC 2169 is at a distance of about 3,600 light years away from Earth. It is nicknamed "The '37' Cluster" due to its striking resemblance to the numerals "37". The cluster is composed of components Collinder 38, a I3pn open cluster, and Collinder 83, a III3m open cluster.


Designations


Standardized Catalogues

NGC 2169


PMC Observatory Catalogue


Observations


  1. 2024-12-21 at around 01:00 am


Location in the sky


Find Betelgeuse, then go upward towards mu Orionis. From there, continue upwards until reaching Xi and Nu Orionis. The cluster should be visible by forming a triangle with Xi and Nu, with the cluster being underneath.




Photographs

The 37 Cluster can be seen at the bottom of this image from my ASI585MC camera. The '3' and '7' are clearly visible.
The 37 Cluster can be seen at the bottom of this image from my ASI585MC camera. The '3' and '7' are clearly visible.

Sketch


Below is a sketch of the 37 Cluster.

NGC 2169, also known as the "37 Cluster," is an open star cluster located in the constellation Orion, about 3,600 light-years from Earth. The cluster is named after the distinctive pattern formed by its brightest stars, which resemble the number "37" when viewed through a telescope. Containing around 30 stars, NGC 2169 is notable for its young age of approximately 10 million years, a clue to which lies in the nature of its brightest star, HD 41943 or in the sketch above NHC 2169 1. This binary system consists of stars of spectral classes B0 and B2, both of which are hot and massive. The B0 star, in particular, is the hottest and most massive of the B-type stars, just below the O-class stars in temperature and mass, making it a key indicator of the cluster's youth. The presence of HD 41943, with its B-type stars, is a telltale sign that NGC 2169 is still in the early stages of stellar evolution. These stars burn through their fuel at a much faster rate than cooler stars like our Sun, and they will evolve into red giants or explode as supernovae much sooner. This rapid evolution supports the idea that the cluster is young, as these massive stars have not yet had the time to reach their final stages. The blue hues of the stars in NGC 2169 further emphasize this, as the blue color indicates high surface temperatures, typically between 10,000 and 25,000 K, which is characteristic of young, hot stars. With an apparent magnitude of 5.9, NGC 2169 is visible through binoculars or small telescopes, especially under good viewing conditions. The cluster’s compact shape and the arrangement of its brightest stars make it a visually striking object in the night sky, easily recognizable by its "37" pattern. Studying clusters like NGC 2169 provides valuable insights into the formation and evolution of young stars, as well as the dynamics of star clusters in their early stages.
NGC 2169, also known as the "37 Cluster," is an open star cluster located in the constellation Orion, about 3,600 light-years from Earth. The cluster is named after the distinctive pattern formed by its brightest stars, which resemble the number "37" when viewed through a telescope. Containing around 30 stars, NGC 2169 is notable for its young age of approximately 10 million years, a clue to which lies in the nature of its brightest star, HD 41943 or in the sketch above NHC 2169 1. This binary system consists of stars of spectral classes B0 and B2, both of which are hot and massive. The B0 star, in particular, is the hottest and most massive of the B-type stars, just below the O-class stars in temperature and mass, making it a key indicator of the cluster's youth. The presence of HD 41943, with its B-type stars, is a telltale sign that NGC 2169 is still in the early stages of stellar evolution. These stars burn through their fuel at a much faster rate than cooler stars like our Sun, and they will evolve into red giants or explode as supernovae much sooner. This rapid evolution supports the idea that the cluster is young, as these massive stars have not yet had the time to reach their final stages. The blue hues of the stars in NGC 2169 further emphasize this, as the blue color indicates high surface temperatures, typically between 10,000 and 25,000 K, which is characteristic of young, hot stars. With an apparent magnitude of 5.9, NGC 2169 is visible through binoculars or small telescopes, especially under good viewing conditions. The cluster’s compact shape and the arrangement of its brightest stars make it a visually striking object in the night sky, easily recognizable by its "37" pattern. Studying clusters like NGC 2169 provides valuable insights into the formation and evolution of young stars, as well as the dynamics of star clusters in their early stages.

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