[vsnet-chat 256] New variable stars, etc.

[bas@lowell.Lowell.Edu (Brian Skiff)]

     Perhaps one of the historical reasons for the lack of a way for new
variable stars to be verified and announced in a timely manner is that since
the Second War the authority for this has been with the GCVS group in Moscow.
Until 'glasnost', and even after, this has meant communications from Russia
have been relatively slow or even not possible for many political, financial,
and technical reasons, such as the lack of computers and telecommunications
infrastructure in Russia.  As Russia slowly gets it politico-economic act
together, perhaps the GCVS editors will be able to disseminate the information
on variable stars more often than just once every year or so (the current rate
of publishing new name-lists).
     My perspective on this is as a professional who wants the contributions of
active, reliable amateurs to be known and recognized among professionals.
There is no reason good work by amateurs should be excluded from publication in
places that professionals will have access to.  I find it unsatisfying that
amateur observers put in so much work, and merely send in their data to a
variable-star organization, only to have it disappear without their being
adequately recognized.  The AAVSO, VSOLJ, AFOEV, etc. are excellent ways of
coordinating observations, providing lists of targets, and so on, but when a
personal observing project has matured, I would encourage you publish the
results on your own!
     Getting stuff out nowadays means publishing one's results in a journal
that is indexed by SIMBAD and/or by the bibliographic databases maintained at
Goddard and by the Harvard group, and eventually by the cooperative "Urania"
project.  This is a rapidly evolving area, and surely in the future more
journals will be covered by these services.  The well-known "Astronomy and
Astrophysics Abstracts" volumes, as indispensable as they were in the past, are
now being superceded by the on-line facilities.  (The Lowell Observatory
library is among many institutions who have cancelled their standing orders for
the very expensive A&A Abstracts tomes.)
     I would again argue that the preferred place to publish new variable-star
discoveries is the IBVS ("Information Bulletin on Variable Stars").  This is
the publication sanctioned by the IAU Commission on variable stars, making it
comparable to the IAU Circulars, which are sanctioned by various solar-system
and small-bodies groups within the IAU.  Most importantly, the IBVS reports are
indexed by author/title in the Harvard ADS system (http://adswww.harvard.edu)
and object-by-object in SIMBAD.  They are issued in batches about every six
weeks, and the refereeing process usually takes only a few days---lightning
fast compared to an ordinary journal!  As each report is prepared for printing,
LaTex and PostScript files are posted on the Konkoly Web site, ready for
downloading for free (http://ogyalla.konkoly.hu/IBVS/IBVS.html).  Publishing
papers in the journal is free up to a limit of four pages.  (Many professional
journals extract a "page charge" for the privilege of publishing---over US$100
per page for the three big American journals.)
     I agree with Kiyota-san that the IBVS is not widely read by amateurs, but
since it is both available and indexed on the Web, it is accessible by anyone
with the proper link.
     I can also understand the reticence of amateurs fearing to publish in
case, for instance, there might be a serious error of some kind.  But anything
you wish to submit should be reviewed first by knowledgeable peers, and also
by a professional before submitting it to the IBVS (or anywhere else).  This is
no different that what happens with professionals, who will commonly ask a
colleague at their institution (or elsewhere) to look over a paper before it is
sent in.  I understand that amateur/professional contact in Japan in particular
is very good, and it seems there is plenty of expertise available to check
things out ahead of time---and to produce new experts at CCD reductions, 
period-finding, etc., as has been discussed here.
     To me the real work, and the really valuable contribution amateurs can
make, is the observations themselves.  It is easy to find stars that are
varying, just as it is easy to find new asteroids.  The hard work is following
the star long enough and with enough observations to tell what kind of variable
it is.  Although it is permissible to announce a new variable star based on
preliminary work, it is best if the following can be provided:

1)  A precise position, good to about 1 arcsecond.  Now that the U. S. Naval
Observatory's "A1.0" catalogue has two search engines for it on the Web...

http://asteroid.lowell.edu/cgi-bin/koehn/webnet

http://vizier.u-strasbg.fr/cgi-bin/PMM-USNO-A1.0

...there is now no reason to have to measure the position for any star that
appears on a sky survey plate as faint as mag. 20 or so.  Many CCD observers
have software allowing astrometry to be done on a star, which can be used to
identify a variable in catalogues such IRAS, the GSC, etc.

2)  Elements of variation.  Most variables have some sort of periodicity in
their variations.  The period and amplitude of the variations are fundamental
to characterizing the type of variable.  Thus you want to determine at least
approximately:
     a)  the full magnitude range, at least approximately calibrated;
     b)  the period, as best the data will allow;
     c)  the type of variable (eclipsing, Mira, semiregular, RR Lyr, etc.).

3)  Finally, it is best when publishing to provide a finding chart.  For the
stars fainter than about mag. 10-12, the chart should show an area no larger
than about 10 arcminutes.  (Outside the Milky Way, the field might be somewhat
larger.)  Since charts can be produced from the Digitized Sky Survey, no
special photos or CCD frames need to be taken, although they too can be used.
The IBVS, by the way, prefers to receive PostScript figures, but they also
accept clear linework charts as well, such as plots made from the GSC.

     If you would like to see a very good example of amateur work that fits
these requirements, see Lennart Dahlmark's latest publication in the IBVS,
issue 4458, which is now available from the IBVS Web site mentioned above.
I helped him get precise positions and identifications for the stars, but all
the real work of observing, measuring the plates and films, and of lightcurve
construction was done by Dahlmark.  The publication includes these results plus
charts for each of the 60 stars.  This is a significant publication any
observer could be proud of.
     Kato-san notes that there are many variables spotted by nova hunters and
others that have not been followed up.  Perhaps these can be collected and
published preliminarily in the VSOLJ bulletins.  And once enough data are
obtained to get periods, etc., they can be issued more formally in the IBVS,
perhaps in groups by each observer, or collectively.
     Once material is ready for publication, I will be happy to look over
papers ready to submit to the IBVS to smooth out rough English or to check
for conspicuous problems.  I'm sure there are other 'vsnet' readers, both
professional and amateur, who can offer to do this as well.

     Finally, I will note that there will be meetings among both professional
and amateur variable-star observers coinciding with the IAU General Assembly
in August, which will be held in Kyoto.  It would seem like that would be an
excellent opportunity for all interested parties to establish communications,
and led by the hometown 'vsnet' guys!  I believe Laszlo Szabados, the co-editor
of the IBVS, will be at the meeting, so he could provide details about the
journal requirements and other advice for amateur contributors
     All for now.  I hope this encourages observers to collect their data on
new variables to make them available for the rest of us!

\Brian Skiff  (bas@lowell.edu)

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp