Star cluster NGC 1904, also known as Messier 79, is a relatively old globular cluster. It can be found in the southern constellation Lepus. NGC 1904 was discovered in 1780 by Pierre Méchain, a French astronomer that was known for studying deep sky objects and comets. It is believed that cluster NGC 1904 is not native to the Milky Way galaxy, rather comes from Canis Major Dwarf Galaxy. This star cluster is a class V globular cluster, with an apparent magnitude of 7.7v, a distance of 12.9kpc from Earth, and an estimated age of 11.7 million years (Wikipedia).
In April of 2022, a study written by Leanza, S, et al. and published by the American Astronomical Society, concluded that present-day kinematic properties of NGC 1904 are consistent with those of a dynamically old system that has lost a significant fraction of its initial angular momentum (Leanza, et al. 2022).
Images of NGC 1904 were collected through Skynet Robotic Telescope Network using telescopes PROMPT-MO-1 and Prompt5. Five images of each filter type were captured one hour apart using filters: B with 180.0 second exposures, V with 90.0 second exposures, and R with 60.0 second exposures, for a total of 15 images. These images were collected to analyze the relationship between the colours, brightness, age, and chemical composition of the star cluster. Using these images of star cluster NGC 1904, it was determined that the cluster has a RA proper motion of 2.473 mas/yr and DEC proper motion of -1.6, a distance of 19.69 kpc, an age of 8.88 log(yr), a metallicity of -1.62 solar, and E(B-V) of 0.09mag.
Figure 1. ISM-reddened image of NGC 1904
Figure 2. De-reddened image of NGC 1904
Figure 3. Cluster pro plus graphs of NGC 1904
Through The Milky Way Star Cluster Catalog, the parameters of NGC 1904, were determined to be: RA proper motion of 2.473 mas/yr and DEC proper motion of -1.6, a distance of 12.892 kpc, an age of 10.1 log(yr), a metallicity of -1.44 solar, and E(B-V) of 0.01mag.
Figure 4. Cluster pro plus graphs of NGC 1904 from MWSC published values
It appears that the MWSC parameter values plotted over the Gaia and 2MASS data create a more
accurate graph than my own estimated parameters. The estimated motion and number of cluster
stars were very close to the published data, the estimated distance and age was pretty far off from
the published data, and the estimated metallicity and E(B-V) were a little off from the published
data. I do not think my analysis of cluster NGC 1904 improves upon previously published
values, but I was able to determine some similar values to that of the published data.
Studying star cluster, such as NGC 1904, is useful, as the values listed above provide insight to how stars form and evolve.