Coordinates of findings for KStars, Stellarium -> iTelescope.net?
30 Jul 2017 21:55:09 UTC
Topic 209011
(moderation:
Hello,
This itelescope.net site is a great attractor. For something like 3 years I have an account with them and once put some money in, just I never not really had anything to look for. Sigh. A couple of minutes ago the idea arose to look at the pulsars that E@H finds. The Wikipedia page on pulsars has some nice pictures on https://en.wikipedia.org/wiki/Pulsar and I had happily procrastinated into an amateur astronomer who took time lapse videos on a pulsar https://youtu.be/lBfCQt6TTms?t=6m54s - and a more professional version on https://youtu.be/lBfCQt6TTms?t=5m44s - the other videos of DeepSkyVideos are also nice. Anyway, not knowing much about how to do it, I felt confident that I could somehow script something that orders telescope time of some sort to take a picture every other week of I don't know how many pulsars.
But where are they? I found table 3 in https://arxiv.org/pdf/1611.01015.pdf with something that I interpreted as coordinates and looked a first one up in kstars. Nothing annotated at that point. I then tried to search for the name in kstars - nothing. Back on the Wikipedia page I found a ref to http://www.atnf.csiro.au/research/pulsar/psrcat/download.html which is kind of a funny software/data mixup, but which indeed knew the pulsar names of that table 3 and found me same coordinates and frequencies:
$ ./psrcat -e2 -db_file psrcat.db J0002+6216
PSRJ J0002+6216
NAME J0002+6216
RAJ 00:02:58.17 2.000e-02
DECJ +62:16:09.4 1.000e-01
ELONG 37.55
ELAT 54.07
PEPOCH 55806
F0 8.6682478274 1.000e-10
F1 -0.448354E-12 5.000e-18
P0 0.1153635682680 1.400e-12
P1 5.96703E-15 7.000e-20
SURVEY FermiBlind
POSEPOCH 55806
DMEPOCH 55806.00
ASSOC GRS:3FGL_J0002.6+6218[aaa
AGE 3.06e+05
TYPE NRAD
DATE 2017
PMERR_PA 135.562
BSURF 8.4e+11
B_LC 5.13e+03
EDOT 1.5e+35
RAJD 0.74238
DECJD 62.26928
OSURVEY 0004000000
GL 117.33
GB -0.07
XX 0.00
YY 8.50
ZZ -0.00
EPHVER 2
UNITS TDB
So, from that bit of a downturn from my kstars experience I thought that I should first somehow find a way to offer that data as a kstars module. This is where kstars gets extra info for asteroids or so. While I do not know if I truly want to use kstars or stellarium or neither for the scripting, somehow it feels that this data should be there. They have a list of supernovae, so why not pulsars. Kstars/Stellarium also has the ephemerides of satellites, so with Pulsars discussed as a future GPS for interstellar travel (https://en.wikipedia.org/wiki/X-ray_pulsar-based_navigation) those seem like truly missing.
The psrcat tool is very flexibly on how it reads/interprets/prints the .db file. The SURVEY field should indicate who found/confirmed the pulsar. There are multiple:
$ ./psrcat -db_file psrcat.db -c "NAME RAJ DECJ SURVEY" | head -n 15 -------------------------------------------------------------------------------------------------------------------------
# NAME RAJ DECJ SURVEY
(hms) (dms)--------------------------------------------------------------------------------------------------------------------------
1 J0002+6216 cwp+17 00:02:58.17 2 cwp+17 +62:16:09.4 1 cwp+17 FermiBlind
2 J0006+1834 cnt96 00:06:04.8 2 cn95 +18:34:59 4 cn95 ar4
3 J0007+7303 aaa+09c 00:07:01.7 2 awd+12 +73:03:07.4 8 awd+12 FermiBlind
4 J0011+08 dsm+16 00:11:34 114 dsm+16 +08:10 8 dsm+16 ar327
5 B0011+47 dth78 00:14:17.75 4 hlk+04 +47:46:33.4 3 hlk+04 gb1,gb2,gb3
6 J0023+0923 hrm+11 00:23:16.87910 3 mnf+16 +09:23:23.871 1 mnf+16 FermiAssoc
7 J0024-7204aa phl+16 00:24:05.67 0 mam+06 -72:04:52.62 0 mam+06 misc
8 J0024-7204ab phl+16 00:24:08.1657 4 phl+16 -72:04:47.616 2 phl+16 misc
9 B0021-72C mld+90 00:23:50.35311 9 fck+03 -72:04:31.4926 4 fck+03 pksgc
10 B0021-72D mlr+91 00:24:13.87934 7 fck+03 -72:04:43.8405 3 fck+03 pksgc
...
I am not really sure about it how it should be presented in kstars. We would somehow want to separate the binary from the singular pulsars. And admittedly I still want to see the community-found ones somehow singled out, even though this is kind of ridiculously unscientific. Maybe that's why.
So, what do you think, should there be a E@H Kstars module for pulsars? Is there a subclass of pulsars that is more likely than others to be of value to amateur astronomers? Just direct me, please.
Cheers,
Steffen
This little script transforms
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This little script transforms the ATNF Pulsar Catalogue into a KStarts catalogue that can be loaded - runs on Linux after the download and compilation that database:
./psrcat -db_file psrcat.db -c "NAME RAJ DECJ S400 S1400 SURVEY" | \awk 'BEGIN {print "# Delimiter: ";
print "# Name: ATNF Pulsar Catalogue"
print "# Prefix: ATNF";
print "# Color: #ff0000";
print "# Epoch: 2000";
print "# Flux Frequency: 400 Mhz";
print "# Flux Unit: mJy";
print "# ID RA Dc Tp Mj Mn Pa Nm Flux"};
/^[0-9]/ {print ($1, $4, $7, 18, "", "", "", $2, ("*"==$10)?0:$10)}' \
> atnf.txt
Instructions on how to load an extra catalogue from within KStars are at https://docs.kde.org/stable5/en/kdeedu/kstars/catalogs.html.
I chose the flux of 400 instead of the also offered 1400 since more entries in the database featured it. Substitute the $10 with $13 in the awk print line for the other. For a focus on specific surveys you may add a grep.
The iTelescope.net instructions push to using Stellarium. So, we'll see, instructions for including the same data with that other software may follow ;o) I still need to figure out how to best map their telescopes with the pulsars and the time of the year - but I presume I want to keep the telescope fixed for each pulsar to the degree that this is possible, so, hey, a subset of circumpolar pulsars for each observatory sounds like a good start.
grep ' +' atnf.txt | sort -r -k +3 -t ' ' # northern hemispheregrep ' -' atnf.txt | sort -k +3 -t ' ' # southern hemisphere
The database accomodates for 2613 pulsars. This means some work or some further selection :)
I'm afraid you will be quite
)
I'm afraid you will be quite disappointed pointing an optical telescope at pulsars: very few are actually visible at all using equipment accessible to amateurs. Remember, those objects are very small (we believe they are about 20 km in diameter only), and very hot (which means that the part of their radiation that they emit because of their temperature peaks at wavelengths that are much shorter than what our eyes are sensitive to).
As you pointed out, you can indeed detect the pulsar in the Crab nebula in visible light tho, even with very modest equipment. Also, some pulsars (surely the Crab) are still surrounded by the remnants of the supernova explosions that created the pulsars, or by nebulae caused by the "winds" of material that are blowing around the vicinity of pulsars, and they are indeed nice targets for optical astronomy and astro-photography, but of course those interesting objects will already be covered in catalogs used by Stellarium, Kstars and the like.
Cheers
HB
A stellarium catalog of the
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A stellarium catalog of the E@H discoveries can be downloaded from http://albert.phys.uwm.edu/EatH_mastercat.txt . I'm not sure how recent it is, it might require an update.
BM
Thank you both for your kind
)
Thank you both for your kind and constructive replies. I admit that part of the exercise to me was to just go and learn how to have an automated astronomical image acquisition with today's commercial services. And, in my mind, it does not matter so much if there is something to see or not. In a way, to be pointed to all those locations where there is something that you can only see because of its gravitational effect I find just as interesting. So, the pattern of surrounding stars just make up some nature-produced "QR-Code" of a pulsar - astrometry.net would translate that back to coordinates :) - and I think I'd like to see that, just to get some pictorial impression.
For the pictures themselves I thought one might have some public data, so I had a look at the SDSS (Sloan Digital Sky Survey). But they have only parts of the sky covered that does not seem to overlap with the E@H coordinates, leaving me with full-sky microwave data of 2MASS. The nicest pictures are provided by the overlays from multiple sources with Google sky - though the stability of that site does not live up to the quality of other Google products. Anyway, here a quick impression.
Positive Control: M1 in 2MASS and Google
Top of the E@H list
J0811-3857 in 2MASS
J1227-6210 in 2MASS
J1305-6639 in 2MASS
...
J1322-6251 13:22:21.8 -62:51:44.5 in 2MASS and Google
J1455-5922 14:55:04.7 -59:23:00.0 in 2MASS and Google
I was most suprised that Google Sky did not know about the pulsars. I mean - when googling e.g. for J0811-3857 we should see a little box to the right much in analogy to what we see when googling for an address or the Eiffel tower. What we see is a reference to einstein@home.
So, in summary, because the public image data does not seem to cover "our" pulsars, it would make some sense to take pictures ourselves. And Bikeman was right in postulating that nothing would be seen. Would you adopt images for your site should I (or someone else) eventually come up with some sufficiently decent ones?
steffen_moeller schrieb:In a
)
FWIW, we do not find the radio or gamma-ray pulsars because of their gravitational effect. They are discovered, as their names suggest, by their emission of radio waves and gamma radiation. The fact that nothing can be seen simply comes from the fact that they are very faint sources in that part of the electromagnetic spectrum we call light and can see with our eyes.
Cheers,
Benjamin
Einstein@Home Project
;) Thank you, Benjamin. Yes,
)
;) Thank you, Benjamin. Yes, of course. The binary pulsars E@H found long before the first gravitational wave. And (guessing) the frequency of graviational waves of any regular binary system is likely to be far too low to be detectable. Some head banging helped to get me back on track. That is - I still feel like having optical telescope look at those sites our communty has identified as special for non-optical reasons. And even when that is a bit "pointless" (as in "missing the pulsar"), hey, you still get a picture of .. well .. its neighbourhood. And it answers my question where to look for asteroids as a bit of a hobby.
Besides iTelescope.net I have now came across Slooth as a tantalizing provider of telescope time. The list of pulsars from the ATNF catalog I imported to KStars I have imported to my KStars "wishlist"-to-observe. It is a bit tedious since KStars does not offer radio sources as potential objects to look at - how comes they do know I do not have a radio telescope? - so each is selected by name. Once in the wishlist, one changes the location to where the remote telescope is and KStars tells which subset of pulsars can be "seen" how much above the horizon at this or a later night. I liked it. One can also export the observation list in an XML format. Nice.
If someone reading this has already worked with the "Astronomer" program of Slooth - that is about $25 a month - sounds flattering but it is what one needs to observe arbitrary coordinates - then please speak out about what the experience was like. Can I import observation lists? I yet failed to find any documentation on how to reserve the instruments prior to having sent the money. Any users of other services out there? Ok - my next post in this thread better features some optical foto of E@H pulsars.