How to plot YB6 stars in Guide is detailed.

_Background_

There's a certain amount of fascination with the NOMAD catalogue
amongst some. For Guide users most of NOMAD is already available, as
the USNO B1.0, UCAC2 and 2MASS data are already downloadable and
plottable in Guide, whilst Guide already has Tycho2 and Hipparcos
within it (and some also have the full UCAC2). So the use of NOMAD
tends to double up what already exists in Guide, and it carries no
particular extra information to that included in the other catalogues.

But the YB6 is in NOMAD, and this seems to fascinate people for two
reasons. First, it is an unpublished USNO product which is
unavailable separately, so it only exists in NOMAD. This is still the
case, to some extent. However, it is a digitisation of the plates
from the Yale Proper Motion surveys, so anyone using the NPM1 and NPM2
(Northern PM 1 and 2 catalogues), and, the SPM2.0 or better still the
SPM3.3 (Southern PM version 2 or version 3.3) will already have access
to a lot of this data, although not all.

Second, it carries 'V magnitudes'. In fact these are photographic
magnitudes taken through a yellow filter in much the same way 'quick
V' images have been taken by POSS (equatorially) and other surveys in
the past, and although they can be reasonable to around a quarter mag,
all the way down to magnitude 17, in crowded fields they are no better
than any GSC1.x or USNO A/B mag in terms of quality, being up to a
magnitude out.

Nevertheless, if people can get at the data, they might no worry about
it so much, and not feel the need to access NOMAD whilst only
receiving mostly that which they've already got access to.

Note also that many objects in NOMAD logged as unique to YB6 (ie not
in UCAC2 nor USNO B1.0) are also in 2MASS, but NOMAD uses all optical
catalogues if possible before resorting to using 2MASS positions
(although it will use 2MASS magnitudes wherever available), so
relatively very few truly unique YB6 objects will occur.

_The Procedure_

Ensure Guide is not running.

With the latest upgrades of Guide 8 from the internet at
www.projectpluto.com it's now easy to access any dataset available via
VizieR. A little work is needed using a text editor, notepad will
likely suffice, but nothing clever is needed to be known.

HOWEVER, three working files in Guide have to be added to in the text
editor, so for the seriously cautious, back up the files in you Guide
directory (there is no need to back up the subdirectories/subfolders,
just the files in the Guide directory/folder).

Everyone else can simply backup, or make copies in a separate folder
elsewhere, or wherever, of the following three files which are going
to be modified :-

download.txt
strings.dat
win_menu.dat

download.txt will only exist if you have downloaded and used the later
upgrade versions of the program. If you haven't got it, you can't get
extra data from VizieR.

After backing up those 3 files in whatever way load download.txt into
a text editor.

The first few lines will look something like this, but will not carry
as many entries or be exactly like it:-

# Documentation at bottom of file
2798 -cI/305/out&-out.all=0 gsc23.dat
2799 -cII/276/sdss5&-out.all=0&mode==1 sdssdr5.dat
2800 -cII/270/catal tcs.dat
2801 -cB/denis/denis denis.dat
2802 -cI/297/out&r=Y yb6.dat
end

Access for a new catalogue is entered as a line before the "end"
statement.

In this instance I already have several catalogues that will be extra
to most, whilst not having several other catalogue retrieval routes in
the original because of having the full catalogues on hard disk (eg
ucac2 and cmc14).

The running number in the first column is important, each entry must
have a unique number.

In this instance the number chosen is 2802. Someone already having
gone past 2802 needs to pick the next number after their last entry.
Someone who hasn't gotten that far can use whatever number is next.

This number must be remembered, it will be used elsewhere.

In download.txt enter the line beginning 2802 exactly as shown, cut
and paste it if needed. Edit 2802 to be the number desired by your
system. If you have not as yet reached 2802, you can use 2802 even if
you have not used any of the immediately previous numbers, as long as
you never use it for something else in download.txt. ie, enter

2802 -cI/297/out&r=Y yb6.dat

on the line immediately before the one saying "end", and change 2802
as desired.

Now Guide knows whereabouts in VizieR to look for the data. It is
actually selecting the YB6 unique entries from NOMAD as per the above
URL segment.

When it finds it, it will save it to a file in the Guide
directory/folder called

yb6.dat

which is an ascii file, a raw text file.

Now we need to get Guide to do this action when we want.

The toolbar could be used, but the YB6 unique objects (ie ones not in
UCAC2 nor USNO B1.0 nor 2MASS) are actually quite sparse (which is the
reason using all of NOMAD just to get the odd YB6 object is overkill).

That's a bit of a waste of a toolbar button, which soon fill up the
menu bar if we're not careful.

So, we'll add the invocation command to the menu under

EXTRAS->Get Star Catalog Data

If you run Guide now and look under that menu you will see there are
already options to get data from CDROM and the internet in that
submenu. You must now close Guide, and indeed ensure Guide is not
running before making and saving any further changes.


Get YB6 from Internet will be added to the bottom of that list.

Ensure win_menu.dat is safely backed up somehow, load it into a text
editor, and look down the file towards the end. As the menues go
right to left on screen, the entries in win_menu.dat are top to bottom
in the same order, more or less.

You will eventually see some entries like

2550 1545 Get UCAC2 from Internet

this is the group that is being looked for.

Under the last entry of that group (although above Clear Ax.0 data if
that is the last entry) add the following line

2802 1563 Get YB6 from Internet

This is where the 2802 comes in, this links to download.txt, when this
menu item is called, the same number action is run in download.txt...

...so IF YOU'VE USED SOMETHING OTHER THAN 2802 CHANGE THE ABOVE ENTRY
TO USE THE NUMBER YOU'VE USED.

Now we have another slightly pedantic problem.

In the above entry the second number column is the line number in
strings.dat where the text for this menu command also lives.

It will likely not be 1563 on your machine. It will be very close to
that number, as not much extra is added to my strings.dat from normal.

The end of strings.dat looks something like this (it will wordwrap,
all lines should star with [] )

[] Anything following a [] is a comment. Comments can be added
freely at
[]the end of this file, since GUIDE refers to strings by line number; no
[]attempt is made to read past the last "meaningful" piece of text.
[] Most comments were added just to help translators figure out
where and
[]how that text is used.
[] Lines 1026-1028 contain color values for planets; they are used
if (a)
[]colored planets are available and (b) the planet has no bitmap.

with a linespace before them. The entry before this gap line is the
last in the menu. You will enter a new line after this, and it is the
number of that line you need to know for replacing the 1563 value in
win_menu.dat in the above example for adding YB6 to win_menu.dat.

It's not as hard as it sounds. Most text editors and ascii viewers
will count lines. Or import it as ascii into excel as one whole
column for the lot, and the row number will be the line number, yep,
just checked that, it works.

The new line in strings.dat simply reads

Get YB6 from Internet

So now with the line

2802 1563 Get YB6 from Internet

in win_menu.dat (with your number replacing 2802 from what you used in
download.txt and your line number from strings.dat replacing 1563)

all are connected to each other.

Now ensure Guide is not running still, and apply the above.

From now on whenever Get YB6 from Internet is selected for any
reasonably small field YB6 stars will be added to the file YB6.dat in
the Guide directory/folder.

Now all that is needed is to be able to view the data.

Simply cut and paste the following data into a text editor and save it
as the file YB6.tdf in the Guide directory/folder.

Now whenever you are in a field of two degrees or less and have
downloaded YB6 data, should any exist for that field, these will be
plotted as white stars to the V magnitude, or if there is no V
magnitude as small dotlike circles, where the B magnitude can be found
via right click (this should only occur for stars fainter then V mag
around 18 which are blue enough to be brighter in B mag so will be for
very faintest objects, so a small dot will suffice).

Right click on these and the V mag (visual photographic plate mag, and
around +/- 0.3 mag at best, +/- 1+ at worst, especially in crowded
fields) and any B (blue photographic plate mag, ditto on quality, and
_not_ contemporaneous with the V mags) and any proper motion details
(not necessarily of the highest accuracy) are presented. More info
gives the RA and Dec quoted directly from the data in decimal degrees
(accuracy likely better than USNO B1.0 but probably never as good as
UCAC2, it's a photographic survey remember) and converted via Guide
into sexagesimal, as well as quoting the errors on the proper motion,
and repeating the rest of the right click data again.

And that, as they say, is that. You can probably do it all in less
time than it takes to read this.

Typical coverage is exemplified by a quarter degree field centred on
the sparse field around the cataclysmic variable AL Com. Only seven
stars are unique to YB6.

Cheers

John

John Greaves

---yb6.tdf copy from the next line----
file yb6.dat
title YB6 from VizieR
volatile
RA H 21 9
units0 -2
de d 34 9
mag 94 6
~b 24 1 YB6 Star\n\n
~b 94 6 Vmag %s\n
~b 84 6 Bmag %s\n
~r 21 9 \nRA 2000 %R\n
~r 34 9 Dec2000 %D\n\n
~r 21 9 RA %s Dec %[34,9] deg\n\n
~c 51 7 muRA %s mas/y\n
~c 68 7 muDe %s mas/y\n
~r 51 7 RAcos(Dec) proper motion : %s +/- %[61,4] mas/year\n
~r 68 7 Declination proper motion : %s +/- %[78,4] mas/year\n

epoch 2000
type 6
type sCffffff;e0,0,6;
field 0.00 20.00
mag lim 22.0
shown 5
end
----------copy only up to the previous line---------

check the long lines starting

~r 51

and

~r 68

for wordwrap. These are the last two lines before the gap line and
the follow line "epoch 2000", and should read as two lines, not three
or four.