A plaque attached to Pioneer 10 and 11 as well as Voyager 1 and 2
contained a "Pulsar Map" of 14 pulsars as a way for extraterrestrial
beings to locate earth. What are the names of these Pulsars and where
are they located?

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Clarification of Question by eurisko97-ga on 20 Jan 2003 15:19 PST

Excuse me, I asked about pulsars, the correct stellar object is a
quasar. Sorry for the confusion.

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Request for Question Clarification by tar_heel_v-ga on 20 Jan 2003 16:23 PST

Eurisko97,

Actually, they are pulsars.

http://quest.arc.nasa.gov/pioneer10/mission/

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Clarification of Question by eurisko97-ga on 20 Jan 2003 18:21 PST

*chuckles*

Ooopsie. So they are. Should have known better 

In anycase, I'm intrested in learning which pulsars these are.

Eurisko..

Wow.  Your question was very interesting and I would have thought that
with a little digging, the information would not be that difficult to
uncover.  I couldn't have been more wrong.  After spending about 5 or
so hours researching your question, I sent an email to Robert
Johnston, the webmaster of Johnston's Archive,
http://www.johnstonsarchive.net/astro/, which is a fantastic
collection of the astronomy resources.  Here is a breakdown of our
first correspondence:
"That has got to be the most interesting question I've gotten to date.
 All I know right now is that Frank Drake came up with the map at the
last minute shortly before the launch of Pioneer 10 in 1972 and that
at the time two of the pulsars had periods known only to seven places
(decimal or binary, I don't know).  If nothing else, I should be able
to work it out from the map, right?  I'll see what I can find out.
 
Bob Johnston
----- Original Message ----- 
To: wrjohnston@prodigy.net 
Sent: Monday, January 20, 2003 7:41 PM
Subject: Pulsar question

Good evening...
 
I hope I am not intruding, but I was doing some research and was
hoping you might be able to help.  The plaque on the various Pioneer
spacecraft has an interstellar map that shows 14 pulsars as a way of
finding Earth.  Which 14 pulsars are these?
 
Thanks!"

Now, from his initial response, I didn't hold out much hope for being
able to get a concrete answer.  Wrong again.  This morning, I received
the following:
"OK, I think I have something.  I'm not 100% sure here, but this looks
good:
I came up with a list of 147 known pulsars from 1975 (Taylor and
Manchester,
Astronomical Journal, 1975, 80:794+) and came up with apparent matches
to
the periods and approximate distances in a depiction of the pulsar map
in
Murmers of Earth (Sagan et ali, 1978).  I haven't yet measured angles
from
the diagram, which would provide addition confirmation, but these
periods
match to within 1 ppm for 10 pulsars, and one part in 50,000 to one in
800
for the other four.  Here are the 14, clockwise from the line
indicating
direction to the center of the galaxy:

J1731-4744 = B1727-47
J1456-6843 = B1451-68
J1243-6423 = B1240-64
J0835-4510 = B0833-45
J0953+0755 = B0950+08
J0826+2637 = B0823+26
J0534+2200 = B0531+21
J0528+2200 = B0525+21
J0332+5434 = B0329+54
J2219+4754 = B2217+47
J2018+2839 = B2016+28
J1935+1616 = B1933+16
J1932+1059 = B1929+10
J1645-0317 = B1642-03

Once I finish some checks, I'll post some details on my web site.  (I
had
e-mailed the Planetary Society and asked them, but got no response;
the SETI
Institute would be another possible source.)"

Once we have these listings, you can go to the Princeton Pulsar Map
Applet at http://pulsar.princeton.edu/pulsar/map/PulsarMap.html and
you can get additional information about the respective pulsars.  If
you click on "Search By Name" and enter the information on the left
hand side of the list above without the "J" it plot the location of
the pulsar on the map.  Make sure that at least the box that is
labeled "Match Jnames" is checked.

If Mr. Johnston provides any additional information, I will let you
know.  I have to say that this has been a great question to research
and I hope the above information has been helpful.  If you need any
additional clarification, please let me know prior to rating my
answer.

Regards,

-THV

Search Strategy:
pulsar map

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Request for Answer Clarification by eurisko97-ga on 03 Feb 2003 13:06 PST

That was /excellent/ work. Sorry it took so long for me to look back.
This week was already difficult on me personally, and then with what
happened this weekend. :-/

Anyway. Please post any follow up information as you get it. I will go
give you a nice rating for your wonderful answer now. :-)

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Clarification of Answer by tar_heel_v-ga on 03 Feb 2003 13:22 PST

Eurisko..

Thanks so much for the rating and the generous tip.  It was very
enjoyable researching this for you.  Now, you want more info, you got
it.  I spoke with the gentlemen who did the research and he has set up
an entire web page strictly on this question:

Reading the Pioneer/Voyage Pulsar Map
http://www.johnstonsarchive.net/astro/pulsarmap.html

Enjoy!!

-THV

I went to google answers with this question when it was impossible to
do this with a simple websearch. This was the first time I've ever
used this service and I am thoroughly pleased.

Hello eurisko97

I've only been able to find that the pulsars are located in the Milky
Way:

"The representation of humans is accompanied by a chart: a pattern of
lines beside the figures standing for the 14 pulsars of the Milky Way,
the whole being designed to locate the sun of our universe."
http://www.aber.ac.uk/media/Documents/S4B/sem08.html

"It also has a polar plot of the positions of 14 pulsars relative to
the Sun, with the pulsars specified by giving their periods as base 2
integers - but with trailing zeros inserted to cover inadequate
precision."
http://www.wolframscience.com/reference/notes/1189c

The names given to pulsars are, for the most part numeric codes:
"No universal naming convention for all the potential gamma-ray
pulsars interesting for GLAST to observe. Some pulsars have only "PSR
Jxxxx+xx" name, while Geminga doesn't have a "PSR" name. Some pulsars
have multiple names (e.g. the Crab pulsar).
PSR Jxxxx+xx[xx[aa]] 
All radio pulsars have this type of name.
Radio-quiet pulsars (such as Geminga) do not have this type of name. 
PSR Bxxxx+xx 
Some, but not all radio pulsars have this type of name.
Radio-quiet pulsars (such as Geminga) do not have this type of name. 
Unique name (e.g. Crab, Vela, Geminga) 
Only several famous pulsars have a name of this type.
Newly discovered non-radio pulsar will have this type of name, most
likely.
CatalogName Jxxxx+xx[xx[aa]] 
Geminga is also 3EG J0633+1751.
Even radio-quiet pulsars can have this type of name. 
Although most pulsars have an official "PSR J" name, newly discovered
non-radio pulsars (such as "Geminga-like" pulsars) will not have such
a name until their pulsations are detected in radio wavelengths. Some
theoretical works indicate that GLAST will discover several to a few
tens of radio-quiet pulsars."
http://glast.gsfc.nasa.gov/ssc/dev/psr_tools/issue.html

I sent an email to a pulsar expert I found on a newsgroup.  He replied
that it was one of the most interesting questions he has had to date
but is going to try by looking at the map todetermine which ones they
are and will get back to me.

Regards,

-THV

Thank you very much for your efforts. Let's hope we can get an answer
somehow sometime soon. :-)