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ATEL # 2670; V.P. Goranskij (SAI, Moscow University), E.A. Barsukova and T.A. Fatkhullin (Special Astrophysical Observatory, Russia)
on 11 Jun 2010; 20:10 UT
Password Certification: Vitaly Goranskij (firstname.lastname@example.org)
Subjects: Optical, Nova
Classical nova V458 Vul (N Vul 2007 No.1) was detected as a supersoft X-ray source by the Swift XRT (ATel#1246, #1603). This star is interesting with its spectral class change: features of Fe II class nova completely changed by features of He/N class in the SSS phase (T.N. Tarasova, IBVS No.5807).
We performed spectral observations of V458 Vul with the Russian 6-m telescope BTA and spectral camera SCORPIO on 2010 June 9.84 UT. The exposure was 1200 s. The spectrum was taken in the long-slit mode with the resolution FWHM 10 A in the wavelength range 3100-7300 A. The position angle of the slit was 135 degrees. In such position, bright knots of nebulosity are visible in the slit in the monochromatic light of different spectral lines at both sides from the stellar spectrum at the distance of 3".6 to NW and 4".3 to SE from the star. The SE knots are brighter in all the lines. There are also faint knots seen in some lines, and scattered radiation. In Balmer lines, the structure expands by 27".5 along the slit. In addition to Balmer lines, we identified nebulosity in He II 4686 A, [O I] 6300 and 6363 A, [O II] 7319 A, [O III] 4958, 5006 A, N I 6708, 6723 A, [N II] 5754, 6548, 6583 A, and N IV 7129 A.
On the next night, we have taken direct CCD images of V458 Vul with UBVR_c filters with the SAO 1-m Zeiss reflector. The seeing was 1".4. In the R band frame taken in June 10.92 UT with the exposure 420 s, faint jet-like structure is seen at p.a. 125 degrees and in the opposite direction. The location of the structure turned out close to position of spectrograph slit accidentally.
Fragments of BTA/SCORPIO spectra and R band image