Showing posts with label NGC 869. Show all posts
Showing posts with label NGC 869. Show all posts

Thursday, 9 October 2025

The Double Cluster re-visited



 
The Double Cluster - NGC 869 and NGC 884. Modded Canon 200d DSLR with Dual Band Filter and 135mm Samyang Lens.




Map Credit: freestarcharts.com

" Both Kurt and Pip have never believed that they have done the Double Cluster justice. When you look at this pair of open star clusters, through binoculars or a widefield eyepiece on  a telescope at low magnification, it is truly magnificent.  The Double Cluster, viewed through the JPO's tripod mounted 11x80mm.binoculars, is a joy to see in its jewel like appearance. If you have a pair of binoculars and it's a clear night in the Northern Hemisphere, why not try and find it between Cassiopeia and Perseus? - Joel Cairo CEO of the Jodrell Plank Observatory.

"The Double Cluster in Perseus, catalogued as NGC 869 and NGC 884, is a striking pair of young, massive open star clusters located in the Perseus arm of the Milky Way Galaxy. Situated at an approximate distance of 7,500 light-years (2.3 kpc) from Earth, the system lies within the Perseus OB1 association, an active star-forming region rich in hot, luminous stars.

Both clusters are estimated to be relatively young, with ages on the order of 12–14 million years, placing them in a comparable evolutionary stage. Their stellar populations are dominated by early-type B-class main-sequence stars and a notable complement of evolved blue and red supergiants, evidence of rapid stellar evolution in high-mass stars. Integrated spectral analyses indicate a near-solar metallicity, consistent with their origin in a typical Galactic spiral-arm environment.

The clusters are physically separated by only a few hundred light-years, suggesting a common origin from the same giant molecular cloud. Their projected angular separation on the sky is approximately 30 arcminutes (roughly the apparent diameter of the full Moon), making them easily distinguishable yet visually connected in telescopic and binocular observations.

Photometric studies of NGC 869 and NGC 884 reveal high stellar densities in their cores, with mass estimates of several thousand solar masses each, placing them among the most massive open clusters in the Milky Way. Their combined luminosity and concentration of bright, blue stars make the Double Cluster an archetypal laboratory for studying the early dynamical evolution of clustered stellar populations.

Owing to their brightness (apparent magnitudes ~+4.3 and +4.4) and their location near the Perseus–Cassiopeia border, the Double Cluster has been recognized since antiquity, though it was first catalogued systematically by Hipparchus around the 2nd century BCE. Today, the system remains a prominent observational target for both professional astrophysical research and amateur astronomy, offering insight into star cluster formation, stellar evolution, and Galactic structure". - Professor G.P.T. Chat visiting astrophysicist at the Jodrell Plank Observatory.



Tuesday, 5 November 2024

Caldwell 14 or NGC 869 and NGC 884 on an autumnal night over Lowestoft. - 'The data rides again'!

The Double Cluster - widefield. Credit: Pip Stakkert.

The Double Cluster cropped. Credit: Pip Stakkert.

" Pip Stakkert wasn't at all pleased with Kurt Thrust's processing of the data in our last post. He has been badgering me all week to let him have a go at reprocessing the data and today I finally relented and let him have his turn. In my opinion these images are far superior to Kurt's". - Joel Cairo CEO at the Jodrell Plank Observatory.

Friday, 25 October 2024

Caldwell 14 or NGC 869 and NGC 884 on an autumnal night over Lowestoft.

The Double Cluster or Caldwell 14 in Perseus.
Canon 600d DSLR with F2 Samyang lens f=135mm
on a Star Adventurer EQ mount.: Image credit: Kurt Thrust

 " A very nice clear night in Lowestoft on 24-10-2024 but the rising Moon was a bit of a problem. We decided to image the Double Cluster, NGC 869 and NGC 884 using a widefield format. The above image was created by stacking 60x60 sec exposures at ISO800. Part of the Heart and Soul Nebula is visible top right. On another clear night we may try to image both, in one field or create a two pane mosaic." - Joel Cairo CEO of the Jodrell Plank Observatory ' The UK's most easterly observatory' 

Cropped and reworked detail