Bill Owen wrote:

Dave Typinski wrote:
Chris L Peterson wrote:
On Wed, 17 Mar 2010 10:43:07 -0400, Dave Typinski
wrote:

I have run into a few older papers that have some angular measure
notation with which I'm unfamiliar.

For example, 0.'25 and 0."25, with the quote marks directly over the
decimal point in each case.

I suspect that these denote 25 arcmin and 25 arcsec respectively, but
I'd like to be sure about that.
I'm sure your interpretation is correct. It is a common style to attach
units to the integer part of a value. You see it in new papers as well,
although the trend is definitely away from it. In astronomy, it also
shows up in other notation, such as RA = 5h.3 (with the 'h'
superscripted).

Thanks, Chris. Yes, I did see that sort of notation for RA. I ran
into the tickmarks-on-the-integer oddity in a Soviet paper from 1964;
I wasn't positive that it wasn't some form of grad measure notation.
Thanks for clearing that up.
--
Dave

As other posters have pointed out, the correct interpretation is 0.25
arc minutes for the first example, 0.25 arc seconds for the second.
It's common enough that AASTeX has defined macros for these.

I suspect that the motivation was to save one column, back in the days
when star catalogs were typed and columns were precious.

Thanks, Bill (and Chris and MC and Bud and John)! Very helpful!
--
Dave