Ursa Major cluster


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Ursa Major cluster

An open cluster containing over 100 stars that are scattered over an area of sky more than 1000 minutes of arc in diameter; its wide angular diameter is due to its proximity to Earth. It includes the stars Beta (β), Gamma (γ), Delta (δ), Epsilon (Ɛ), and Zeta (ζ) Ursae Majoris in the Plough, and also Sirius.

Ursa Major cluster

[′ər·sə ′mā·jər ‚kləs·tər]
(astronomy)
An open cluster of stars, including 5 bright stars of the constellation Ursa Major, centered about 75 light-years from the sun and spread over a volume of 30 light-years length and 18-light-years width.
A cluster of galaxies in the constellation Ursa Major having a redshift of about 0.051.
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References in periodicals archive ?
Using a different approach, Gonzalez et al (2010) obtained a family of finite thin-discs models for four galaxies in the Ursa major cluster in which the circular velocities were adjusted to fit the observed rotation curves.
The observational data were taken from Verheijen & Sancisi (2001) for three specific galaxies in the Ursa Major cluster: NGC 3726, NGC 3877 and NGC 4010.
Finite thin disc models of four galaxies in the Ursa Major cluster: NGC 3877, NGC 3917, NGC 3949 and NGC 4010.
(2010) obtained finite thin disc models for four galaxies in the Ursa Major cluster: NGC3877, NGC3917, NGC3949 and NGC4010.
In order to adjust the previous model to the real observed data, we have taken a sample of spiral galaxies from the Ursa Major cluster. We pick the corresponding data out from Table 4 of the paper by Verheijen & Sancisi (2001), which presents the results of an extensive 21 cm-line synthesis imaging survey of 41 galaxies in the neighborhood of the Ursa Major cluster using the Westerbork Synthesis Radio Telescope.
We have presented a mass model for a set of twenty six spiral galaxies of the Ursa Major Cluster. The model is adjusted very precisely with the data of the rotation curve of the galaxies of the sample, considering that all the mass is concentrated only in the stellar disc.
The closest of all star clusters, the Ursa Major Cluster, now shines nearly overhead.
Based on these works, in Gonzalez, Plata-Plata and Ramos-Caro (2010) were obtained some thin disc models in which the circular velocities were adjusted to very accurately fit the observed rotation curves of four spiral galaxies of the Ursa Major cluster, galaxies NGC3877, NGC3917, NGC3949 and NGC4010.
In order to illustrate the above model to the real observed data, we have taken a sample of spiral galaxies of the Ursa Major cluster. We pick the corresponding data out from Table 4 of the paper by Verheijen and Sancisi (2001), which presents the results of an extensive 21 cm-line synthesis imaging survey of 41 galaxies in the nearby of the Ursa Major cluster using the Westerbork Synthesis Radio Telescope.
Finite thin disk models of four galaxies in the Ursa Major cluster: NGC3877, NGC3917, NGC3949 and NGC4010.