Binocular Universe: Taking Aim at the Archer
Posted 03 August 2013 - 07:04 AM
By Phil Harrington
Posted 03 August 2013 - 11:52 AM
Great stuff, as always. There certainly are plenty of goodies to view in and around Sagittarius. I have always loved the interplay of light and dark along the Milky Way. The star clouds and clusters for bright glows and dark areas as a contrast to that.
Lots of fun;
Posted 04 August 2013 - 05:03 AM
Posted 06 August 2013 - 03:13 AM
Phil, reading your nice article I wondered if you happened to post the wrong finder chart? NGC 6774 isn't even on it.
There was a CN thread some years ago, see here about NGC 6774. I continue to appreciate the Eagle shape highlighted there. Phil, you posted an excellent chart in that thread.
Posted 06 August 2013 - 04:58 AM
Also good point about the "Eagle" in NGC 6774. Thanks for the link to that thread from 2007!
Posted 06 August 2013 - 09:20 PM
In this article, the list of objects provided at the end refer to stuff farther north, in Aql, Ser and Oph for the most part...
Incidentally, NGC 6774, or Ru 147, is very interesting. The Tycho data had revealed it to be much more populous than formerly thought, and it is now known as the nearest of the old clusters. Back in 1999 I had written software to plot color-magnitude diagrams and proper motion vector diagrams from Hipparcos/Tycho data, for the study of possible, unknown open clusters I had stumbled upon using 10X50s. I also studied this cluster, and found nearly 90 members in a 2 degree circle. I derived an age of about 2 billion years and a disrance of about 1,000 l-y. The one member which has a puplished radial velocity measure, a red giant, allowed to roughly determine the galactic orbit parameters based on the epicycle approximation (I did not have nor could I write code to do orbit integrations in the Galactic potential.)
I was gratified to eventually read that a paper had been authored in 2005, the synopsis of which generally confirmed my crude findings.
Posted 07 August 2013 - 05:30 AM
Here is the correct list. Note that the correct finder chart and object list are included with the downloadable PDF version of the column.
Posted 10 August 2013 - 07:43 AM
I've sent a corrected chart to the CN webmaster for replacement.
Sorry for the delay, replaced the chart just now!
Posted 27 August 2013 - 06:55 AM
M22 was terrific -nice bright glow -i also enjoyed the triangle asterism shadowing them
6716 was underwhelming -to be honest in my 15x51 it was no diff to the background of the milky way
6774 was better -a nice little string of faint stars , bit like an octopus with one short & one long tentacle
Posted 28 August 2013 - 04:07 AM
But yes, N6774 is much more interesting visually.