page_title: Lambda Orionis Cluster
section_title: Molecular ring and cluster evolution
hierarchical_section_title: Lambda Orionis Cluster / Molecular ring and cluster evolution
caption_attribution_description: English: The head (Meissa) and shoulders (Betelgeuse and Bellatrix) of the constellation Orion with surrounding nebulas as depicted in infrared.
context_page_description: The Lambda Orionis Cluster is an open star cluster located north-west of the star Betelgeuse in the constellation of Orion. It is about five million years old and roughly 1,300 ly away from the Sun. Included within the cluster is a double star named Meissa. With the rest of Orion, it is visible from the middle of August in the morning sky, to late April before Orion becomes too close to the Sun to be seen well. It can be seen from both the northern hemisphere and the southern hemisphere.
context_section_description: The cluster might have formed in the central region of an elongated cloud, which is supported by the distribution of pre-main-sequence star candidates, which are concentrated in the cluster and nearby regions in an elongated shape. Massive OB stars and low-mass stars formed in the central regions of these clouds. The low-mass stars closest to the massive stars likely lost their circumstellar disks due to photoevaporation. Many low-mass stars parsecs away were unaffected by this and represent the current population of low-mass stars with a circumstellar disk. The cluster is surrounded by a large molecular ring, called the Lambda Orionis ring. This was interpreted as a remnant of a supernova that exploded one Million years ago. The supernova blast encountered the clouds and gas in the region and the blast dispersed the parent core, creating the molecular ring.
caption: Molecular Ring in infrared as seen by WISE
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