Nova em Sagitário 2002

 

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Nova em Sagitário 2002
Asteroide Rasante 2002NY40

 

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Explosão de Nova em Sagitário V4741 SAGITTARII

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Texto Explicativo

Após informação de Liller na VSNET sobre suposta nova em Sagitário confirmamos a descoberta e fizemos a astrometria e fotometria de precisão. O tempo estava ventoso e a estrela a apenas 15 graus do horizonte leste. As condições eram ruins. 10 minutos depois da imagem o tempo fechou...Antes das fotos vemos abaixo a circular da descoberta.

 Circular No. 7878
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)


POSSIBLE NOVA IN SAGITTARIUS
W. Liller, Vina del Mar, Chile, reports his discovery, on two
Technical Pan films (+ orange filter) taken on Apr. 15.354 UT, of
an apparent nova (mag 9.2) located at R.A. = 18h00m.1, Decl. =
-30o54' (equinox 2000.0). A CCD image taken with a 0.25-m
reflector by P. Cacella, Brasilia, Brazil, on Apr. 16.093 yields V
= 10.1 and R.A. = 17h59m59s.63, Decl. = -30o53'20".5. The closest
catalogued object appears to be a very red star in the USNO-A2.0
catalogue that is some 3" away (blue mag 19.4, red mag 16.9;
position end figures 59s.47, 18".7). Additional magnitudes
(visual unless otherwise noted): Apr. 11.40, [11.5 (Liller; Tech
Pan films); 13.814, [11.0 (K. Kanatsu, Matsue, Shimane, Japan;
T-Max 400 film; communicated by T. Kato, Kyoto); 14.78, [8.5 (A.
Pearce, Nedlands, W. Australia); 16.129, 9.5 (R. Y. Shida, Sao
Paulo, Brazil); 16.485, 9.8 (M. Linnolt, Honolulu, HI).

Posição

Ra 17h 59m 59.633 s    Dec -30 53´20.52  Photometry V = 10.1

Imagem de CCD com um SCT 10" F4.1 e um CCD HX516 10 segundos de exposição

Dat04-16-2002  2:14 UT

Brasilia - Brasil   16S 48W

Imagem obtida com um SCT 10" F4.1 16.04.2002 2:14 UT

 

DSS2/AAO Vermelho Centrado na Nova

Progenitora identificada como

USNO-A2.0 0525-31255131

Posição J2000 RA 17 59 59.473 DEC -30 53 18.69

BMag 19.4 Rmag 16.9

ESO MAMA/CAI Azul centrado na Nova

                                                  Circular No. 7879
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)

POSSIBLE NOVA IN SAGITTARIUS
     W. Liller, Vina del Mar, Chile, reports his measurement for
the position of the possible nova reported on IAUC 7878:   R.A. =
17h59m59s.38 +/- 0s.08, Decl. = -30o53'21".9 +/- 1".0 (equinox
2000.0).  On Apr. 16.40 UT, a low-dispersion objective-prism CCD
spectrogram, taken by Liller with a 0.20-m Schmidt camera, showed
the object to have narrow H-alpha in emission with a strength about
2.5 times that of the surrounding continuum (FWHM approximately 800
km/s); H-beta is present but very faint, suggesting that the object
is considerably reddened.  The [Fe II] multiplet-42 lines also seem
to be present.  On Apr. 16.3814, Liller measured the star's
magnitude to be V = 9.84.  T. Kato, Kyoto University, reports that
K. Haseda (Aichi, Japan) found nothing to magnitude 13.1 on a T-Max
400 film taken on Apr. 12.79.
 

                                                  Circular No. 7882
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)


V4741 SAGITTARII = POSSIBLE NOVA IN SAGITTARIUS
     N. N. Samus, Institute of Astronomy, Moscow; O. Durlevich,
Sternberg Institute; and E. Kazarovets, Institute of Astronomy,
inform us that the designation V4741 Sgr has been given to this
object (cf. IAUC 7878, 7879).
     M. Fujii, Okayama, Japan, reports that low-dispersion spectra
(range 440-720 nm; resolution about 1 nm) of this object, obtained
on Apr. 18.80 UT with the Fujii Bisei Observatory 0.28-m telescope,
show a strong H-alpha emission line with a width of 2800 km/s
(FWHM).  Other emission lines include the Fe II series (37, 38, 42,
49, 55, 74), Na I (589 nm), and He I (706.5 nm), characteristic of
an Fe II-class nova.  Additional photometry provided by T. Kato,
Kyoto:  Apr. 4.769, [11.8 (A. Takao, Kita-kyushu, Japan,
unfiltered CCD); 12.794, [14.0 (K. Haseda, Aichi, Japan, T-Max 400
film; revision to IAUC 7879); 17.828, 9.6 (Takao); 17.769, V =
10.16 (K. Nakajima, Kumano, Mie, Japan, CCD); 17.788, R_c = 9.31
(Nakajima).
 

                                                     Circular No. 7887
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)

V4741 SAGITTARII
E. Gosset, Institut d'Astrophysique, Liege, writes that a
high-resolution spectrum (range 380-900 nm; resolution 48000) of
V4741 Sgr, acquired on Apr. 19.4 UT using the European Southern
Observatory 1.5-m telescope (+ FEROS) at La Silla, shows the
following full widths at zero intensity (FWZI) and at half-maximum
(FWHM) for the lower Balmer lines: H-alpha, FWZI = 4100 km/s, FWHM
= 2800 km/s; H-beta, FWZI = 3850 km/s; H-gamma, FWZI = 3800 km/s.
H-beta and the upper members of the series are comparatively faint,
suggesting marked reddening (cf. IAUC 7879). The interstellar
absorption lines related to the Na resonance doublet exhibit a
rather complex structure that can be partitioned into three
families. The first one is composed of a broad, damped line at
about -2 km/s, blended with a narrow line at about -30 km/s. The
second family is composed of a narrow line at about -107 km/s with
a faint line in the blue wing. The third family is made of three
partly blended lines at about -143, -150, and -160 km/s. A fourth
family at about -190 km/s could possibly be present. The first
three families are also visible, with less resolution, in the Ca**+
H and K doublet. Gosset adds: "The existence of features up to
such velocities is interesting. If these lines were considered as
being due to interstellar material showing galactic rotation, we
could conclude that the object is situated at a distance quite
comparable to that of the Galactic center or even beyond, in good
agreement with the reported reddening. However, high-velocity
shells are known to exist in the Carina region. The first family
component at -2 km/s is also detected for K, CH, and CH**+."
Visual magnitude estimates: Apr. 16.606 UT, 9.8 (A. Pearce,
Nedlands, W. Australia); 18.134, 10.3 (R. Y. Shida, Sao Paulo,
Brazil); 18.776, 10.6 (Pearce); 19.755, 10.7 (Pearce).

(C) Copyright 2002 CBAT
2002 April 30 (7887) Daniel W. E. Green