Spectral Observations of the Novalike Star TT Ari

Melikian, N. D.; Karapetian, A. A.

doi:10.1023/b:asys.0000049783.03703.1b

Cited by 4 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted that both in the normal state of the star and during its deep minimum, the HeI Table 2 lists the equivalent widths EW of the most intense emission lines that were measured in each of the spectra. It can be seen clearly that except for the last 4 spectra, the equivalent widths of the emission lines are comparable to those obtained previously [13,14]. It can be seen in Figs Hγ absorption is lacking during the deep minimum (Fig.…”

Section: Observational Resultssupporting

confidence: 87%

“…[13,14]. As during the earlier observations, small oscillations in the brightness and changes in the equivalent widths of the spectrum lines were recorded.…”

Section: Observational Resultssupporting

confidence: 76%

“…was found [13,14]. Further observations have confirmed this correlation and shown that a similar correlation exists between all the emission lines, except for the NIII/CIII emission [14].…”

Section: Introductionsupporting

confidence: 62%

“…Our first observations of TT Ari [13] yielded some interesting details that differed from earlier data [8,12]. In particular, the Hγ emission line and the anti P Cygni Hα line profile were found to be absent.…”

Section: Introductioncontrasting

confidence: 56%

“…It is assumed that broad absorption develops in the inner layers of the accretion disk and in the photosphere of the white dwarf, and subsequently broadens further owing to the pressure effect [12,13] and, to some extent, owing to the star's rapid rotation.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Spectral and photometric observations of TT Ari. III.

et al. 2010

Self Cite

View full text Add to dashboard Cite

The nova-like cataclysmic variable (CV) TT Ari was detected in its second deep minimum inNovember 2009. Study of its evolutionary phase is very important for research on the nature of CVs in the VY Scl group. During this phase the spectral energy distribution of the star changed rapidly. The emission lines of elements with high excitation, such as HeII λ4686 and NIII/CIII, as well as broad absorption in the hydrogen Balmer series, originating in the photosphere of the white dwarf or in the lower layers of an accretion disk, vanished. The average ratio of the intensities of the Balmer series emission lines in the normal state and in the deep low state can be explained in terms of a simple photoionization-recombination model. At the same time, the intensity ratios of the triplet-singlet levels of neutral helium, HeIλ5876/ HeIλ6678, differ greatly in the normal state of the star and in its deep minimum. In the deep minimum, the star's spectrum contains only a very faint trace of the G band at a wavelength λ4300Å, together with flarelike events with amplitudes up to 0 2 m . m ≈ Δ or greater. These and some other observed characteristicsindicate that during the deep minimum it is mainly emission from the secondary companion of the binary system, which is probably a T Tau star of an early K spectral class, that is observed.

show abstract

Section: Observational Resultssupporting

confidence: 87%

“…[13,14]. As during the earlier observations, small oscillations in the brightness and changes in the equivalent widths of the spectrum lines were recorded.…”

Section: Observational Resultssupporting

confidence: 76%

“…was found [13,14]. Further observations have confirmed this correlation and shown that a similar correlation exists between all the emission lines, except for the NIII/CIII emission [14].…”

Section: Introductionsupporting

confidence: 62%

Section: Introductioncontrasting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Spectral and photometric observations of TT Ari. III.

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

Spectral observations of the novalike star TT Ari. II

et al. 2008

Self Cite

View full text Add to dashboard Cite

Results from a spectral study of one of the brightest cataclysmic variables, the star TT Ari, are presented. They are generally in good agreement with previous observations, but there are some differences. The luminosity of the star, as well as the equivalent widths of emission lines, reveal variations that are probably periodic in character. Emission from the star in the CIV 5801Å and 5812 Å lines is observed for the first time. The observed variations in the symmetry of the broad absorption Balmer series (beginning with Hβ) may be a consequence of the appearance of a P Cyg line profile. The Hα line manifests a P Cyg profile consisting of two components corresponding to 600 and 1900 km/s. The average of the ratio EWHα /EWHβ indicates that the formation of these lines may be explained, at least partially, in terms of a simple photoionization-recombination model.

show abstract

Nova-Like Cataclysmic Variables in the Infrared

Hoard

Long

Howell

et al. 2014

ApJ

View full text Add to dashboard Cite

Nova-like (NL) cataclysmic variables have persistently high mass transfer rates and prominent steady state accretion disks. We present an analysis of infrared observations of 12 NLs obtained from the Two Micron All Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer All Sky Survey. The presence of an infrared excess at λ 3-5 μm over the expectation of a theoretical steady state accretion disk is ubiquitous in our sample. The strength of the infrared excess is not correlated with orbital period, but shows a statistically significant correlation (but shallow trend) with system inclination that might be partially (but not completely) linked to the increasing view of the cooler outer accretion disk and disk rim at higher inclinations. We discuss the possible origin of the infrared excess in terms of emission from bremsstrahlung or circumbinary dust, with either mechanism facilitated by the mass outflows (e.g., disk wind/corona, accretion stream overflow, and so on) present in NLs. Our comparison of the relative advantages and disadvantages of either mechanism for explaining the observations suggests that the situation is rather ambiguous, largely circumstantial, and in need of stricter observational constraints.

show abstract

Spectral Observations of the Novalike Star TT Ari

Cited by 4 publications

References 0 publications

Spectral and photometric observations of TT Ari. III.

Spectral and photometric observations of TT Ari. III.

Spectral observations of the novalike star TT Ari. II

Nova-Like Cataclysmic Variables in the Infrared

Contact Info

Product

Resources

About