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Strange angular measure notation?



 
 
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  #1  
Old March 17th 10, 02:43 PM posted to sci.astro.amateur,sci.physics
Dave Typinski[_3_]
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Posts: 778
Default Strange angular measure notation?

Hello all,

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.

Can anyone confirm what this notation is supposed mean?

Thanks!
--
Dave
  #2  
Old March 17th 10, 03:28 PM posted to sci.astro.amateur,sci.physics
Dave Typinski[_3_]
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Posts: 778
Default Strange angular measure notation?

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
  #3  
Old March 17th 10, 04:14 PM posted to sci.astro.amateur,sci.physics
Some guy in Arizona
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Posts: 10
Default Strange angular measure notation?

On Mar 17, 7:43 am, 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 almost certain the correct interpretation is 0.25 arc-minutes
(i.e., 15 arc-seconds) and 0.25 arc-seconds, respectively. I don't
know where you might find a definitive reference to resolve the
confusion, but I've seen this notation used on occasion, and I'm
fairly sure that's how it works.

Are there any examples listed in the papers that you might compare
to known values as a sanity check?

-- MC --
  #4  
Old March 17th 10, 06:02 PM posted to sci.astro.amateur
William Hamblen[_2_]
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Posts: 236
Default Strange angular measure notation?

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

Hello all,

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.

Can anyone confirm what this notation is supposed mean?

Thanks!


I think it means a decimal fraction of a minute of arc or a second of
arc.

Bud
  #5  
Old March 18th 10, 01:22 AM posted to sci.astro.amateur,sci.physics
Bill Owen
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Posts: 154
Default Strange angular measure notation?

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.

-- Bill Owen
  #6  
Old March 18th 10, 01:24 AM posted to sci.astro.amateur,sci.physics
Quadibloc
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Posts: 7,018
Default Strange angular measure notation?

On Mar 17, 8:43*am, Dave Typinski wrote:
Hello all,

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. *

Can anyone confirm what this notation is supposed mean?


I would have thought that these would mean 1/4 of an arcminute and 1/4
of an arcsecond respectively. I know I've seen it used in that sense.

John Savard
  #7  
Old March 18th 10, 02:16 AM posted to sci.astro.amateur,sci.physics
Dave Typinski[_3_]
external usenet poster
 
Posts: 778
Default Strange angular measure notation?

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
 




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