Context:
Discovered by: Koichi Itagaki (Teppo-cho, Yamagata, Japan), at mag 6.8 (Unfiltred CCD), 2013 Aug. 14.584 UT
Coordinates: R.A. 20 23 30.73 Decl. +20 46 04.1 (2000.0)
Principal Investigator: Steve Shore (University of Pisa).
Results:
This bump started on August 26th as shown in this synthetic graph of my spectra.
While nova's Vmag decreases, Ha line's intensity grows up: the nova should appear more and more reddish.
Last but not least, each plot group corresponds to one night and and each inner spectra are separated by one hour. The increasing ratio of Ha line seems to become higher and higher each night.
Publications:
Continuing spectroscopic observations (3500-8800A) of Nova Del 2013 with the Ondrejov Observatory and the ARAS groupATel #5312; S. N. Shore (Univ. of Pisa,
INFN-Pisa); P. Skoda, D. Korcakova, P. Koubsky R. K?Ã?ek, P.
Rutsch, M. Slechta ((Astronomical Institute, Academy of Sciences of
the Czech Republic- Ondrejov, Czech Republic); O. Garde, O. Thizy ,
T. de France, D. Antao, J. Edlin, K. Graham, J. Guarro, F.
Teyssier, P. Berard, i T. Bohlsen, E. Pollmann, T. Lemoult, A.
Favaro, J.-N. Terry, E. Barbotin, F. Boubault, J. P. Masviel, R.
Leadbeater, C. Buil, B. Mauclaire (contributing participants,
ARAS) Subjects: Optical, Cataclysmic Variable, Nova Observations with the Ondrejov Observatory 2m Zeiss coude spectrograph (R = 18000) are continuing covering the range 3550 - 8870 A (see ATel #5282). High cadence spectroscopic monitoring by the Astronomical Ring for Access to Spectroscopy (ARAS) began on 2013 Apr. 14.8 and has continued uninterrupted covering the wavelength interval at resolutions ranging from 3684 - 7431 A with resolutions ranging from 580 - 11000 with time sequences as short as 10 minutes at resolutions up to 12000. The ARAS spectra(at this writing more than 230) are publicly available at the consortium website: http://www.astrosurf.com/aras/Aras_DataBase/Novae/Nova-Del-2013.htmParticipating observers are throughout Europe, North America, and Australia. The coverage is especially dense during the period spanned by the Fermi/LAt detection and continuing observations. The rapid changes reported by the Liverpool group (ATel#5300) have not only been confirmed but resolved although the shortest interval in which significant line profile changes were detected (R > 700) was > 6 hrs with the variations being far less prominent on Aug. 20. In addition to reports in Atel #5304, ATel #5305, Balmer absorption components were detected to at least H14 on Aug. 22 (HJD 2456522.6) with vrad (abs. min) = -600+/-50 km/s. As reported, the absorption on the lower Balmer lines is also at this low velocity but the emission wings extend now to approximately +/-2000 km/s, consistent with the maximum velocity reported in the first observations from Aug. 14. The Na I D line now shows a complex absorption trough, possibly with components of both the D1 and D2 lines at -850 and -600 km/s. On Aug. 22.8 the Fe II 4921,5018 A showed absorption extending to -1400 km/s with weak indications of incipient narrow absorption at lower velocities. In the 8400-800 A region, O I 8446 may show absorption but has a profile compatible with the Na I emission and no discernible mean redshift. The changes are now relatively slower than during the first week and the nova is likely deep into the Fe-curtain phase in the UV having now passed out of the fireball. The line profiles suggest possible asphericity of the ejecta but it would be premature to speculate further. Multiwavelength spectroscopy, especially in the infrared between 2.1 =- 2.3 microns (for Na I 2.20 micron, CO 2.15 microns, etc) are extremely important now; the only feature clearly present at CN 3883, 4216 are atomic lines (e.g. Ca I 4226) but this is the period during which any molecular formation would be observed; regardless of the rate of optical decline this stage is critical to cover with R > 500 and over broad spectral range. |
| Title:First high resolution ultraviolet (HST/STIS) and supporting
optical spectroscopy of V339 Del = Nova Del 2013 Author:S. N. Shore (Univ. of Pisa, INFN-Pisa); G. J. Schwarz (AAS); K. Alton, D. Antao, E. Barbotin, P. Berardi, T. Blank, T. Bohlsen, F. Boubault, D. Boyd, J. Briol, C. Buil, S. Charbonnel, P. Dubreuil, M. Dubs, J. Edlin, T. de France, A. Favaro, O. Garde, K. Graham, D. Greenan, J. Guarro, T. Hansen, D. Hyde, T. Lemoult, R. Leadbeater, G. Martineau, Y. Buchet, J. P. Masviel, J. Montier, B. Mauclaire, E. Pollmann, J. Ribeiro, B. Schram, O. Thizy, J.-N. Terry, F. Teyssier (contributing participants, ARAS); K. L. Page, J. P. Osborne (Leicester); J-U Ness (ESA); S. Starrfield (ASU); F. M. Walter (SUNY-SB); C. E. Woodward (Minnesota); M. F. Bode (John Moores Univ. Liverpool) Queries:shore@df.unipi.it Posted:22 Sep 2013; 23:24 UT Subjects:Cataclysmic Variable, Nova, Star V339 Del = Nova Del 2013 was observed with the Space Telescope Imagine Spectrograph (STIS) aboard the Hubble Space Telescope (HST) on 2013 Sept. 18.2 UT from 1140-2888 A using the E140M and G230H gratings at a resolution of ~ 100000. At the time, V ~ 8, shortly after t_3. Continuing spectroscopy was provided by the Astronomical Ring for Access to Spectroscopy (ARAS) at resolutions ranging from 3684 - 7431 A with resolutions ranging from 580 - 11000 with time sequences as short as 10 minutes at resolutions up to 12000. The STIS spectra show that the Fe curtain stage was ending at the time, although strong absorption was still detected throughout the STIS range. Emission was detected on Ly alpha, O I 1302, C II 1335, N II] 2142, C II 2324, and Mg II 2800. The absorption at Ly-alpha is dominated now by the interstellar absorption consistent with the optically derived extinction, indicating that the intrinsic neutral hydrogen column density is now likely below 1E20/cm^2. Strong, saturated P Cyg absorption was present on C II 1335 extending to -2500 km/s, about the same as the velocities measured during the fireball stage (ATel#5282). Although heavily obscured by overlying Fe curtain lines, He II 1640A and N IV 1486A may be present. There are no indications of either O III] 1661,1667A or C III] 1909. As observed in T Pyx during the same stage (Day 23 of outburst), the 1180-900 A metallic line absorption were not saturated. The measured flux (1180-2900A) was 1.7e-8 erg/s/cm^2, corrected E(B-V)=0.2(ATel#5304) the flux as 7.8e-18 erg/s/cm^2. Optical monitoring finds that [N II] 5755 A first appeared around Sept. 8, the N III 4640A feature has been recognized shortly before, and after Sept. 10 the He I 5876, 6678, 7065A transitions were observed. The Na I D lines are now gone and the He I 5876 emission shows the optically thin multi-peaked profile typical of the other transitions, e.g. O I 6300,6364. He II 4686 may be weakly present in the N III blend. The Fe II, e.g. 5018A, no longer show the narrow detached absorption features reported earlier although weak absorption remains on H-gamma at -1000 km/s. Comparing these STIS UV spectra with high resolution IUE spectra of the CO nova OS And 1986 obtained between 12 and 21 days after optical discovery (1986 Dec. 17, 26 respectively) shows a very close agreement such that when independently dereddened, they differ by only a scale factor of A~1.5 in flux, indicating that the distance to V339 Del is about 6 kpc (distance to OS And ~ 5.1 kpc with E(B-V)=0.25+/-0.05, see Schwarz et al. 1997, MNRAS, 284, 669). Further observations are planned with STIS in the coming months and we urge continuing optical and near infrared observations of this remarkable opportunity to capture the history of a CO nova in outburst. Due to an error in transcription, the distance is given incorrectly in the text of ATel#5409. Along with the typo "Space Telescope Imaging Spectrograph", the text should read: Comparing these STIS UV spectra with high resolution IUE spectra of the CO nova OS And 1986 obtained between 12 days (LWP) and 22 days (SWP) after optical discovery (1986 Dec. 17, 27 respectively) shows a very close agreement such that when independently dereddened, the ratio of V339 Del to OS And between 1200 and 1900A is ~1.5 in flux (similar in the 2000-3000A range but more uncertain because of the earlier date of the long wavelength IUE observation), indicating that the distance to V339 Del is about 4.2 kpc (distance to OS And ~ 5.1 kpc with E(B-V)=0.25+/-0.05, see Schwarz et al. 1997, MNRAS, 284, 669). |
Chronological catalog of spectra:
A webpage with all of spectra is available here.
Pay attention: more than 300 figures are displayed.