Re: trying for exact position of Sgr* radio source at Galactic Center
- Thank you, Diana.
Mark A. Holmes
--- In email@example.com, "Diana K. Rosenberg"
> The Center of the Galaxy is said to be marked by (invisible) radio
> source Sagittarius A* - so I went googling and found this:
> The Astrophysical Journal, 518:L33-L35, 1999 June 10
> q 1999. The American Astronomical Society. All rights reserved.
> THE POSITION OF SAGITTARIUS A* AT THE GALACTIC CENTER
> F. Yusef-Zadeh and D. Choate
> Department of Physics and Astronomy, Northwestern University, 2131
> Road, Evanston, IL 60208-2900; zadeh@n...center of
> and W. Cotton National Radio Astronomy Observatory, 520 Edgemont Road,
> Charlottesville, VA 22903-2475; bcotton@n...
> Received 1999 February 9; accepted 1999 April 7; published 1999 May 19
> The absolute position of the compact radio source at the dynamical
> the Galaxy, Sagittarius A*, wasdetermined the
> known only to an accuracy of 00.2 in spite of its accurate location with
> respect to near-IR stellar sources to within
> 30 mas. To remedy this poor positional accuracy, we have selected 15
> high-resolution, high-frequency VLA
> observations of Sgr A* carried out in the last 13 years and
> weighted average positionm s s
> with the average epoch 1992.4 to be at a, , or h m s s 0 d(1950) 5 17 42
> 29.307650.0007 228759 180.484500.014
> a, ,2297009280. 0.014, which agrees with earlier published values h
> d(2000) 5 17 45 40.038350.0007 06950particularly in
> to within the 00.2 error bars of the earlier measurements. An accurate
> absolute position of Sgr A* can be useful
> for its identification with sources at other wavelengths,
> soft and hard X-rays, with implications(Sagittarius
> for the models of a massive black hole at the Galactic center.
> Subject headings: galaxies: ISM-Galaxy: center-ISM: individual
> A*)letters did
> The trouble with the paragraph above is that symbols and Greek
> not come thru correctly;0.014
> so here it is with the 2000 position, which I converted to celestial
> longitude and latitude:
> (2000) = 17h45m40.0383 + or - 0.0007 secs, -29deg00'28".069 + or -
> which for 2000.0 is: 26Sag 51 06, Lat - 5 36 28, Decl -29 00 28,
> 45 40
> I have corrected my files accordingly (I was slightly off).
> For the present (2006.1), add 5 minutes - it's now 26 Sag 56 10
> By the way the core radio source, Sagittarius A* or Sgr A* is pronounced
> "Sagittarius A-star"
> Love, Diana
> Website: http://pw1.netcom.com/~ye-stars/