Izvleček
V članku rišemo Hertzsprung-Russllov (HR) diagram odprte zvezdne kopice M45 (Plejade). Pri tem uporabljamo podatke, ki jih je zbral vesoljski teleskop Gaia (izdaja EDR3). Podatki so prosto dostopni v podatkovni bazi Gaia Archive. V članku skušamo z uporabo vedno strožjih in vedno bolj specifičnih filtrov iz baze podatkov izbrati zvezde, ki resnično pripadajo izbrani kopici. Za poizvedbo v bazi podatkov uporabljamo programski jezik ADQL, za obdelavo in risanje pa programski jezik Python. HR-diagram izluščenih podatkov nam pove, da je M45 mlada zvezdna kopica, ki vsebuje zvezde z absolutnimi magnitudami v razponu med 0 in 15 mag ter barve med 0 in 3,5 mag. Na HR-diagramu najdemo te zvezde večinoma na glavni veji.
Abstract
Hertzsprung-Russell Diagram of Star Clusters
The article contains a drawing of the Hertzsprung-Russell (HR) diagram of the open star cluster M45 (Pleiad). It is based on the data collected by the Gaia space telescope (EDR3 edition). The data are freely accessible in the Gaia Archive database. The aim of the article is to pick the stars from the database that truly belong to the selected cluster by using increasingly stricter and increasingly specific filters. The ADQL programming language was used for the database search, while the Python programming language was used for processing and drawing. The HR diagram of extracted data tells us that M45 is a young star cluster which contains stars with absolute magnitudes ranging from 0 to 15 mag., and colours from 0 to 3.5 mag. In the HR diagram these stars are mostly located on the main sequence.