* Astronomy

Members Login
Post Info TOPIC: NGC 5466


L

Posts: 131433
Date:
Melotte 124
Permalink  
 


NGC 5466 (also Melotte 124 and GCl 27) is a magnitude +10.5 globular cluster located 51,800 light-years away in the constellation Bo÷tes.

The cluster was discovered by German-British astronomer William Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflectoráat Datchet, Berkshire on the 17th May 1784.á

Right Ascension 14h 05m 27.29s, Declination +28░ 32' 04.0"

It is thought to be the source of a stellar stream discovered in 2006, called the 45 Degree Tidal Stream. This star stream is an approximately 1.4░ wide star lane extending from Bo÷tes to Ursa Major.
Read more



__________________


L

Posts: 131433
Date:
RE: NGC 5466
Permalink  
 


Title: NGC 5466: a unique probe of the Galactic halo shape
Authors: H. Lux, J.I. Read, G. Lake, K.V.Johnston

Stellar streams provide unique probes of galactic potentials, with the longer streams normally providing the cleaner measurements. In this paper, we show an example of a short tidal stream that is particularly sensitive to the shape of the Milky Way's dark matter halo: the globular cluster tidal stream NGC 5466. This stream has an interesting deviation from a smooth orbit at its western edge. We show that such a deviation favours an underlying oblate or triaxial halo (irrespective of plausible variations in the Milky Way disc properties and the specific halo parametrisation chosen); spherical or prolate halo shapes can be excluded at a high confidence level. Therefore, more extensive data sets along the NGC 5466 tidal stream promise strong constraints on the Milky Way halo shape.

Read more (3755kb, PDF)



__________________


L

Posts: 131433
Date:
Permalink  
 

NGC 5466 is a class XII globular cluster in the Bo÷tes constellation. Located 51,800 light years from Earth and 52,800 light years from the Galactic centre, it was discovered by William Herschel on May 17, 1784 and as H VI.9.
It is thought to be the source of a stellar stream discovered in 2006.

Source


Title: The Tidal Tails of NGC 5466
Authors: M. Fellhauer (1), N.W. Evans (1), V. Belokurov (1), M.I. Wilkinson (1,2), G. Gilmore (1) ((1) Cambridge, (2) Leicester)

The study of substructure in the stellar halo of the Milky Way has made a lot of progress in recent years, especially with the advent of surveys like the Sloan Digital Sky Survey. Here, we study the newly discovered tidal tails of the Galactic globular cluster NGC 5466. By means of numerical simulations, we reproduce the shape, direction and surface density of the tidal tails, as well as the structural and kinematical properties of the present-day NGC 5466. Although its tails are very extended in SDSS data (> 45 degrees), NGC 5466 is only losing mass slowly at the present epoch and so can survive for probably a further Hubble time. The effects of tides at perigalacticon and disc crossing are the dominant causes of the slow dissolution of NGC 5466, accounting for about 60 % of the mass loss over the course of its evolution. The morphology of the tails provides a constraint on the proper motion -- the observationally determined proper motion has to be refined (within the stated error margins) to match the location of the tidal tails.

Read more (378kb, PDF)

__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard