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F H O N s u m m a r y 1 9 9 5
I N T R O D U C T I O N
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Finnish Halo Observers Network (FHON):
summary of rare halos in observations of the year 1995
Jukka Ruoskanen (jruoskan_at_snakemail.hut.fi)
and Jarmo Moilanen (jarmom_at_netppl.fi)
With some help from: Marko Riikonen (Marko.Riikonen_at_ursa.fi)
Veikko Makela (Veikko.Makela_at_helsinki.fi)
Marko Pekkola (Marko.Pekkola_at_helsinki.fi)
**************************************************************************
******
More informations about halos? Contact to FHON: halot_at_ursa.fi
**************************************************************************
With this summary we like to show some results of our work which was done
under beautiful skies that were filled with halos to all members of
METEOPTIC!
We hope that you will be encouraged to make your own halo observations and
maybe establish your own network in your country. There are three active
observing groups in the world as far as we know: FHON, group in the
Netherlands
and German halo group. We would like to see more halo networks in the
future!
FHON is collecting observations from its members six times in year. These
observations are represented bi-monthly in the Ursa Minor bulletin of Ursa
Astronomical Association (ursa_at_ursa.fi).
This summary included ONLY halo displays where rare halos were observed
and
usually photographed too.
FHON uses two different observation forms: so called A-form* for common
haloforms and so called B-form for rare halos. So this summary included
only
those B-form observations. Halos from artificical light source and ground
halos
are excluded.
*A-form is called also as a "list form" because it is like a list and
doesn't
give very detailed information which B-form does.
WHICH HALOS ARE NOT RARE?
FHON counts these nine halos as common haloforms:
22 deg halo
Sun pillar
Parhelia (sun dogs)
Tangent arcs (or circumscribed halo when sun is high)
Circumzenithal arc*
46 deg halo
Supralateral arc
Parhelic circle
Subsun.
All halo displays which included only these haloforms are reported in an
A-form
and is not in this summary. These halos are not mentioned in this summary
at
all.
*Circumhorizonthal arc, which may be common halo in low latitudes, is
almost
impossible halo to observe in Finland because sun or moon is never high
enough
(sun elevation have to be more than 58 deg).
NAMES OF HALOFORMS
In generally, names of haloforms in this summary are following agreement
between FHON and German halo group.In this summary two names are not
following that deal. Here is list of those haloforms.
Names used in summary "Old names"
Liljequist parhelia "150-160 deg (Liljequist's) parhelia"
120 deg parhelic arcs "oblique arcs to the 120 deg parhelia"
**************************************************************************
FHON is halo section under subordination of Ursa.
Ursa Astronomical Association
Raatimiehenkatu 3 A 2
FIN-00140 HELSINKI
tel. +358 0 174 048
FAX +358 0 657 728
Current section leader is Veikko Makela (Veikko.Makela_at_helsinki.fi).
- Have a nice skywatching! ***************
FHON **
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