Dátum: 2000. március 11., 17:16
Feladó: Szabo Sandor --
Tárgy: Fw: [PLANOCCULT] Update for (44) Nysa on March 12/13, 2000
Március 13-án, azaz hétfő hajnalban KözEI-ben fél hatkor, azaz hajnali szürkületben a W
Vir nevű változó elfed egy 10 magnis csillagot. A fényességcsökkenés csak 0,8 magnitúdó
lesz, tehát nagyon kedvezőtlenek lesznek a körülmények. Viszont a fedés sávja átmegy
Nyugat-Magyarországon, ahol a pirkadat is később kezdődik. A Nap kb. 7 fokkal lesz a
horizont alatt. Ha még sötétben megkeressük a csillagot, talán követhető lesz a
szürkületben. A fényességcsökkenéshez pedig egy hasonló fényű csillagot kell keresni a
látómezőben, így a közel 1 magnitúdós halványulás szembetűnő lesz. Részletes adatok az
alábbiakban:
A fedés 4:33 UT-kor lesz látható hazánkból, így legalább ez időpont előtt, illetve után 5
percig figyeljünk erősen.
Szabó Sándor
> IOTA/IOTA-ES occultation update for
> (44) Nysa / HIP 65531 = W Vir event on March 12/13, 2000
> visible from frm.Yugoslavia, Austria, SW Czech Republic,
> Germany, Denmark and Norway
>
> Summary
>
> In the morning of night March 12/13, 2000 a ~9.9 mag star HIP 65531 = W Vir
> will be occulted by a 73 km asteroid (44) Nysa. This update is based on
> USNO/Flagstaff and TMO astrometry for the asteroid and Hipparcos star
> position.
>
> The updated path shows no shift with time ~0.3 minutes earlier compared to
> Edwin Goffin's nominal prediction.
>
> The path of this occultation runs over frm.Yugoslavia around 4:33 UT,
> Austria ~4:34 UT, SW Czech Republic ~4:34.5 UT, Germany ~4:35 UT, Denmark
> ~4:36 UT and finally SW Norway ~4:37 UT. Within expected errors is also
> very NE Italy, western Hungary, most of Czech Republic and NE Netherlands.
>
> As was earlier mentioned by Roland Boninsegna on PLANOCCULT list, the
> target star is (prototype) variable W Virginis (subtype of delta Cephei
> variables). I have also tried to find how bright this star could be around
> the time of occultation and have estimated on basis of some AFOEV
> brightness estimates that it could be around 9.9 magnitude, which is
> slightly more optimistic than Roland's estimate. But even with my estimate
> the drop will be only around 0.8 magnitudes. This means that for accurate
> observation are preferred observation by means video camera, IOTA
> occultation camera or CCD drift scans.
>
> The event will take place on twilight sky, with best condition being in
> Germany, Denmark and Norway where the sun will be around 10 degrees below
> horizon. The accuracy of update should be fairly good so even expeditions
> to path with suitable equipment is possible. Good luck for everyone !!!!
>
>
> The event at one glimpse:
> * date and approx. UT time of event: March 13, 2000 04:35 UT
> * magnitude of target star: 9.9
> * magnitude drop [mag]: 0.8
> * estimated maximum duration [s]: 10.0
> * path description: given above
> * Goffin's original chart reference: A00_0311
>
> The occultation path:
> * approximate ground width [km]: 200
> * map: attached or it can be found at following WEB pages:
> http://sorry.vse.cz/~ludek/mp/2000
> Data for the target star:
> * name: HIP 65531 = SAO 139335 = PPM 196502 = W Vir
> * constellation: Virgo
> * J2000 position [h,m,s; o,',"]: 13h 26m 01.993s; -03o 22' 43.42"
> * V mag [mag]: 9.9 approx.
> Target star is in middle Virgo, 7.8 degrees almost exactly north of
> 1.1 mag star alpha Virginis = Spica or 3.5 degrees SW of 3.4 mag star
> zeta Virginis. There is 7.1 mag star SAO 139336 only 17' south of
> target, but this one is much brighter. There is no convenient star
> suitable as reference star for visual observations in close vicinity.
>
> Close finding chart:
> attached or it can be found at following WEB pages:
> http://sorry.vse.cz/~ludek/mp/2000
> Centerline path coordinates:
> Altitude
> E. Longitude Latitude U.T. star sun
> ........ shortened ..........................
> 20 14 49 43 0 0 4 32 26 20 -5
> 18 49 13 44 0 0 4 32 47 21 -6
> 17 29 25 45 0 0 4 33 6 21 -7
> 16 14 48 46 0 0 4 33 26 21 -7
> 15 4 56 47 0 0 4 33 45 21 -8
> Calculator: Jan Manek
>