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Honeycutt, R. K.

Publications and source records attributed to Honeycutt, R. K..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Spectroscopy and photometry of the dwarf nova BZ Ursae Majoris and the CV linewidth/K, mass-ratio relation

Time-resolved spectroscopy of the dwarf nova BZ Ursae Majoris (BZ UMa) reveals periodic velocity variations in the hydrogen emission lines with P = 97.9 +/- 0.1 min and K = 73 +/- 6 km/s. CCD photometry over a 16-month interval shows three outbursts of about 4 mag with a mean separation of 181 days. The mean full width at half maximum (FWHM) for the hydrogen beta emission is large, prompting a recalibration of the FWHM/K vs. mass ratio relation, giving a mass ratio (M(sub RD)/M(sub WD)) of 0.20 for BZ UMa. The short period, long outburst interval, and small mass ratio support the suggestion of BZ UMa being in the SU Ursae Majoris subclass of dwarf novae.

Jurcevic, J. S.↗
NASA NTRS1993

CP Puppis - No ordinary old nova

We present spectrophotometric data for the old nova CP Puppis (Nova Puppis 1942) that demonstrates the simultaneous existence of two distinct periods for the system. We find that the photometric period of 0.06834(7) day is 11 percent longer than the spectroscopic period. We also present Doppler tomographic images of CP Pup that indicate the existence of an accretion disk in the system. Finally, we interpret the observational evidence in terms of a DQ Herculis model and an SU Ursae Majoris model for CP Pup. While the evidence mildly supports both interpretations, it is insufficient for us to conclusively classify CP Pup as either a DQ Her system or an SU UMa system.

White, James C., II↗
NASA NTRS1992

MR Persei - A new rotating, spotted flare star

Spectroscopy and photometry are used to show that MR Persei, an object originally classified as a dwarf nova, is in fact a flare star. The automated CCD photometry consists of sequences of exposures within a single night as well as long-term photometry over a five-month interval. One sequence shows a 30-min flare, accompanied by post-flare 'dips'. A 0.2 mag variation with a period of about one-half day is also seen in this sequence. The long-term photometry is used to refine the period to 0.45483 d, which we attribute to the rotation of a spotted star. Evidence for membership of MR Per in the young Alpha Per cluster is considered, and found to be inconclusive.

Honeycutt, R. K.↗
NASA NTRS1991

Mass loss in the 96 day binary UU Cancri

A series of 16 high-dispersion spectra at H-alpha have been obtained for the tidally distorted K giant-containing long-period binary UU Cnc, in order to both study the K giant's Doppler profiles and search for the effects of accretion onto the second component. While Doppler profiles of the system for a semidetached configuration fit the observations very well, those for existing overcontact light-curve solutions all yield poorer fits. Although the H-alpha line is always stronger than those of the common giants, its equivalent width is consistent with a K4 II classification reflective of the star's 50 solar radius size. Emission wings in H-alpha are possible evidence for an accretion disk.

Eaton, Joel A.↗
NASA NTRS1985

Chromospheric activity and TiO bands in M giants

Low-resolution IUE spectra of 23 cool giant stars ranging from K3 through M6 have been used to examine chromospheric activity in late-type giants. Previous studies have suggested a decrease in the fractional flux, normalized to bolometric flux, of the Mg II resonance lines (an indicator of chromospheric activity) with effective temperature. Using more accurately determined effective temperatures, this decrease is confirmed and found to be more rapid than previously suggested. A strong correlation is found between relative TiO band strengths, as measured by the Wing TiO index, and the level of chromospheric activity, as measured by Mg II fluxes. Cool giants which have weak TiO bands relative to the mean TiO strengths for stars of similar color also have Mg II lines that are weaker than the mean. Changes in composition and in chromospheric activity as a consequence of aging are suggested as a possible origin of this interesting relation.

Steiman-Cameron, T. Y.↗
NASA NTRS1974

On the relation between carbon star spectral types and colors

Observations of 32 carbon stars are listed in a table, taking into account the spectral classes given by Yamashita (1966) and Richer (1971). The relations between spectral type and color for carbon stars appear consistent with the differences between Yamashita's and Richer's types if carbon star groups I-III lie on a decreasing boundary temperature sequence.

Honeycutt, R. K.↗
NASA NTRS1974

Scanner observations of carbon stars from 5000 to 7000 A

New photoelectric spectral scans of 26 N-type and 11 R-type carbon stars are presented. The spectral energy distributions were also measured to gain new insight into the composition, chemistry, and structure of carbon star atmospheres. Using the best continuum points in the wavelength region from 5000 to 7000 A a color index is defined, taking into account fluxes at 0.57 and 0.68 microns. The new color index correlates well with the widely used (V-R) broad-band color index.-

Fay, T. D., Jr.↗
NASA NTRS1973

Scanner observations of hot helium-carbon stars.

Photoelectric spectral scans at 20 A resolution of four hot helium-carbon-rich stars have been reduced to fluxes and are presented in graphical form. Similar flux curves for several normal (hydrogen-rich) stars in the same temperature range are presented for comparison.

Fay, T.↗
NASA NTRS1972

Scanner observations of cool stars from 3400 to 11,000 A.

Evaluation of photoelectric scans of the M supergiant alpha Ori and the carbon stars 19 Psc, W Ori, and DS Peg made at 20-A resolution from 3400 to 6000 A and at 40-A resolution from 6000 to 11,000 A. The data are corrected for atmospheric extinction and for the instrumental response to obtain plots of log flux per unit frequency interval versus wavelength. The dominant spectral features are due to C2, CN, and TiO; the variation of these features with spectral class is pointed out.

Fay, T.↗