Thomas A Fleming

Interests

Teaching

use of technology in the classroom; clickers; planetarium education

Research

X-ray emission from stars

Courses

No activities entered.

Scholarly Contributions

Books

• Fleming, T. A. (2011). Stars. Cognella.
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Chapters

• Marsh, M., Barstow, M., Holberg, J., O'Donoghue, D., Buckley, D., Fleming, T., Koester, D., & Burleigh, M. (1995). An EUV Selected Sample of DA White Dwarfs. In White Dwarfs, Proceedings of the 9th European Workshop on White Dwarfs Held at Kiel, Germany, 29 August - 1 September 1994. Lecture Notes in Physics, Vol. 443, edited by Detlev Koester and Klaus Werner. Springer-Verlag, Berlin Heidelberg New York, 1995., p.328(p. 328).
• Barstow, M., Fleming, T., Diamond, C., & Finley, D. (1992). ROSAT observations of white dwarfs. In The Atmospheres of Early-Type Stars, Lecture Notes in Physics, Volume 401. ISBN 978-3-540-55256-7. Springer-Verlag, 1992, p. 329(p. 329).
• Bond, H. E., Grauer, A. D., Liebert, J., Fleming, T., & Green, R. F. (1987). A search for hot pulsators similar to PG 1159-035 and the central star of K 1-16. In Stellar Pulsation; Proceedings of the Conference held as a Memorial to John P. Cox at the Los Alamos National Laboratory, Los Alamos, NM, Aug. 11-15, 1986. Lecture Notes in Physics, Vol. 274, edited by A. N. Cox, W. M. Sparks, and S. G. Starrfield. Springer-Verlag, Berlin, 1987., p.352(p. 352).

Journals/Publications

• Basri, G., Berger, E., Fleming, T. A., Giampapa, M. S., Gizis, J. E., Liebert, J., Martin, E. L., Phan-bao, N., & Rutledge, R. E. (2010). SIMULTANEOUS MULTI-WAVELENGTH OBSERVATIONS OF MAGNETIC ACTIVITY IN ULTRACOOL DWARFS. III. X-RAY, RADIO, AND Hα ACTIVITY TRENDS IN M AND L DWARFS. The Astrophysical Journal, 709(1), 332-341. doi:10.1088/0004-637x/709/1/332
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  As part of our on-going investigation into the magnetic field properties of ultracool dwarfs, we present simultaneous radio, X-ray, and H? observations of three M9.5-L2.5 dwarfs (BRI?0021-0214, LSR?060230.4+391059, and 2MASS?J052338.2?140302). We do not detect X-ray or radio emission from any of the three sources, despite previous detections of radio emission from BRI?0021 and 2M0523?14. Steady and variable H? emission are detected from 2M0523?14 and BRI?0021, respectively, while no H? emission is detected from LSR?0602+39. Overall, our survey of nine M8-L5 dwarfs doubles the number of ultracool dwarfs observed in X-rays, and triples the number of L dwarfs, providing in addition the deepest limits to date, log(L X/L bol) ?5. With this larger sample we find the first clear evidence for a substantial reduction in X-ray activity, by about two orders of magnitude, from mid-M to mid-L dwarfs. We find that the decline in H? roughly follows L H?/L bol 10?0.4?(SP-6) for SP ? 6, where SP = 0 for spectral type M0. In the radio band, however, the luminosity remains relatively unchanged from M0 to L4, leading to a substantial increase in L rad/L bol. Our survey also provides the first comprehensive set of simultaneous radio/X-ray/H? observations of ultracool dwarfs, and reveals a clear breakdown of the radio/X-ray correlation beyond spectral type M7, evolving smoothly from L ?,rad/L X 10?15.5 to ~10?11.5 Hz?1 over the narrow spectral-type range M7-M9. This breakdown reflects the substantial reduction in X-ray activity beyond M7, but its physical origin remains unclear since, as evidenced by the uniform radio emission, there is no drop in the field dissipation and particle acceleration efficiency. Based on the results of our survey, we conclude that a further investigation of magnetic activity in ultracool dwarfs will benefit from a two-pronged approach: multi-rotation observations of nearby known active sources and a snapshot survey of a large sample within ~50 pc to uncover rare flaring objects.
• Berger, E., Basri, G., Fleming, T., Giampapa, M., Gizis, J., Liebert, J., Mart{\'\in}, E., Phan-Bao, N. .., & Rutledge, R. (2010). Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. III. X-ray, Radio, and H\ensuremath{\alpha} Activity Trends in M and L dwarfs. \apj, 709, 332-341.
• Basri, G., Berger, E., Fleming, T. A., Giampapa, M. S., Gizis, J. E., Liebert, J., Martin, E. L., Phan-bao, N., & Rutledge, R. E. (2009). PERIODIC RADIO AND Hα EMISSION FROM THE L DWARF BINARY 2MASSW J0746425+200032: EXPLORING THE MAGNETIC FIELD TOPOLOGY AND RADIUS OF AN L DWARF. The Astrophysical Journal, 695(1), 310-316. doi:10.1088/0004-637x/695/1/310
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  We present an 8.5 hr simultaneous radio, X-ray, UV, and optical observation of the L dwarf binary 2MASSW J0746425+200032. We detect strong radio emission, dominated by short-duration periodic pulses at 4.86 GHz with P = 124.32 ± 0.11 min. The stability of the pulse profiles and arrival times demonstrates that they are due to the rotational modulation of a B ≈ 1.7 kG magnetic field. A quiescent nonvariable component is also detected, likely due to emission from a uniform large-scale field. The Hα emission exhibits identical periodicity, but unlike the radio pulses it varies sinusoidally and is offset by exactly 1/4 of a phase. The sinusoidal variations require chromospheric emission from a large-scale field structure, with the radio pulses likely emanating from the magnetic poles. While both light curves can be explained by a rotating misaligned magnetic field, the 1/4 phase lag rules out a symmetric dipole topology since it would result in a phase lag of 1/2 (poloidal field) or zero (toroidal field). We therefore conclude that either (1) the field is dominated by a quadrupole configuration, which can naturally explain the 1/4 phase lag; or (2) the Hα and/or radio emission regions are not trivially aligned with the field. Regardless of the field topology, we use the measured period along with the known rotation velocity (v sin i ≈ 27 km s–1), and the binary orbital inclination (i ≈ 142°), to derive a radius for the primary star of 0.078 ± 0.010 R ☉. This is the first measurement of the radius of an L dwarf, and along with a mass of 0.085 ± 0.010 M ☉ it provides a constraint on the mass-radius relation below 0.1 M ☉. We find that the radius is about 30% smaller than expected from theoretical models, even for an age of a few Gyr. The origin of this discrepancy is either a breakdown of the models at the bottom of the main sequence, or a significant misalignment between the rotational and orbital axes.
• Berger, E., Rutledge, R., Phan-Bao, N. .., Basri, G., Giampapa, M., Gizis, J., Liebert, J., Mart{\'\in}, E., & Fleming, T. (2009). Periodic Radio and H\ensuremath{\alpha} Emission from the L Dwarf Binary 2MASSW J0746425+200032: Exploring the Magnetic Field Topology and Radius Of An L Dwarf. \apj, 695, 310-316.
• Berger, E., Basri, G., Gizis, J., Giampapa, M., Rutledge, R., Liebert, J., Mart{\'\in}, E., Fleming, T., Johns-Krull, C., Phan-Bao, N. .., & Sherry, W. (2008). Simultaneous Multiwavelength Observations of Magnetic Activity in Ultracool Dwarfs. II. Mixed Trends in VB 10 and LSR 1835+32 and the Possible Role of Rotation. \apj, 676, 1307-1318.
• Berger, E., Gizis, J., Giampapa, M., Rutledge, R., Liebert, J., Mart{\'\in}, E., Basri, G., Fleming, T., Johns-Krull, C., Phan-Bao, N. .., & Sherry, W. (2008). Simultaneous Multiwavelength Observations of Magnetic Activity in Ultracool Dwarfs. I. The Complex Behavior of the M8.5 Dwarf TVLM 513-46546. \apj, 673, 1080-1087.
• Berger, E., Rutledge, R., Reid, I., Bildsten, L., Gizis, J., Liebert, J., Mart{\'\in}, E., Basri, G., Jayawardhana, R., Brandeker, A., Fleming, T., Johns-Krull, C., Giampapa, M., Hawley, S., & Schmitt, J. (2005). The Magnetic Properties of an L Dwarf Derived from Simultaneous Radio, X-Ray, and H\ensuremath{\alpha} Observations. \apj, 627, 960-973.
• Fleming, T. A., Giampapa, M. S., & Garza, D. (2003). The Quiescent Corona of VB 10. \apj, 594, 982-986.
• Fleming, T. A., Giampapa, M. S., & Schmitt, J. H. (2000). An X-Ray Flare Detected on the M8 Dwarf VB 10. \apj, 533, 372-377.
• Fleming, T. A. (1998). A New Sample of Nearby M Dwarfs Discovered by ROSAT. \apj, 504, 461-467.
• Giampapa, M. S., Prosser, C. F., & Fleming, T. A. (1998). X-Ray Activity in the Open Cluster IC 4665. \apj, 501, 624-642.
• Metanomski, A., Pasquini, L., Krautter, J., Cutispoto, G., & Fleming, T. (1998). F, G and K stars in the ROSAT all-sky survey. I. Photometry. Astronomy and Astrophysics Supplement Series, 131, 197-208.
• Abbott, T., Fleming, T., & Pasquini, L. (1997). The ROSAT cataclysmic variable RX J2353.0-3852.. \aap, 318, 134-139.
• Barstow, M. A., Burleigh, M. R., & Fleming, T. A. (1997). A SEARCH FOR HIDDEN WHITE DWARFS IN THE ROSAT EXTREME ULTRAVIOLET SURVEY. Monthly Notices of the Royal Astronomical Society, 287(2), 381-401. doi:10.1093/mnras/287.2.381
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  The ROSAT Wide Field Camera survey has provided us with evidence for the existence of a previously unidentified sample of hot white dwarfs (WDs) in non­ interacting binary systems, through the detection of extreme ultraviolet (EUV) and soft X-ray emission. These stars are hidden at optical wavelengths because of their close proximity to much more luminous main-sequence (MS) companions (spectral type K or earlier). However, for companions of spectral type '" AS or later, the white dwarfs are easily visible at far-UY wavelengths, and can be identified in spectra taken by the International Ultraviolet Explorer (IUE). Eleven WD binary systems have previously been found in this way from ROSAT, Extreme Ultraviolet Explorer (EUVE) and IUE observations. In this paper we report the discovery of three more such systems through our programmes in recent episodes of IUE. The new binaries are HD 2133, RE J0357 + 283 (the existence of which was predicted by Jeffries, Burleigh & Robb in 1996), and BD + 27°1888. In addition, we have independently identified a fourth new WD + MS binary, RE 11027 + 322, which has also been reported in the literature by Genova et al., bringing the total number of such systems discovered as a result of the EUY surveys to 15. We also discuss here six stars which were observed as part of the programme, but for which no white dwarf companion was found. Four of these are coronally active. Finally, we present an analysis of the WD + KOIV binary HD 18131, which includes the ROSAT PSPC x: -ray data.
• Burleigh, M., Barstow, M., & Fleming, T. (1997). A search for hidden white dwarfs in the ROSAT extreme ultraviolet survey. \mnras, 287, 381-401.
• Dempsey, R. C., Linsky, J. L., Fleming, T. A., & Schmitt, J. (1997). The ROSAT All-Sky Survey of Active Binary Coronae. III. Quiescent Coronal Properties for the BY Draconis-Type Binaries. \apj, 478, 358-366.
• Ottmann, R., Fleming, T., & Pasquini, L. (1997). ROSAT all-sky survey observations of PopII field binaries: X-ray activity of old, metal-poor stellar coronae.. \aap, 322, 785-800.
• Tagliaferri, G., Covino, S., Fleming, T., Gagne, M., Pallavicini, R., Haardt, F., & Uchida, Y. (1997). Coronal X-ray emission of HD 35850: the ASCA view.. \aap, 321, 850-858.
• Briel, U., Fleming, T. A., Greiner, J., Pfeffermann, E., & Snowden, S. L. (1996). CATALOGUE AND LUMINOSITY FUNCTION OF WHITE DWARFS DETECTED IN THE ROSAT ALL-SKY SURVEY. Astronomy and Astrophysics, 316(1), 147-154.
• Fleming, T. A., & Tagliaferri, G. (1996). The X-Ray Spectrum of a Metal-poor Corona. \apj, 472, L101.
• Fleming, T., Snowden, S., Pfeffermann, E., Briel, U., & Greiner, J. (1996). Catalogue and luminosity function of white dwarfs detected in the ROSAT all-sky survey.. \aap, 316, 147-154.
• Giampapa, M., Rosner, R., Kashyap, V., Fleming, T., Schmitt, J., & Bookbinder, J. (1996). The Coronae of Low-Mass Dwarf Stars. \apj, 463, 707.
• Mullan, D., & Fleming, T. (1996). Coronal Heating in dMe and dM Stars: Clues from the X-Ray Surface Fluxes. \apj, 464, 890.
• Werner, K., Dreizler, S., Heber, U., Rauch, T., Fleming, T., Sion, E., & Vauclair, G. (1996). High resolution UV spectroscopy of two hot (pre-) white dwarfs with the Hubble Space Telescope. KPD0005+5106 and RXJ2117+3412.. \aap, 307, 860-868.
• Ayres, T. R., Fleming, T., Simon, T., Haisch, B., Brown, A., Lenz, D., Wamsteker, W., {de, M. D., Gonzalez, C., Bonnell, J., {Mas-, H. J., Rosso, C., Schmitt, J., Truemper, J., Voges, W., Pye, J., Dempsey, R., Linsky, J., Guinan, E., , Harper, G., et al. (1995). The RIASS Coronathon: Joint X-Ray and Ultraviolet Observations of Normal F--K Stars. The Astrophysical Journal Supplement Series, 96, 223.
• Barstow, M., Burleigh, M., Fleming, T., Holberg, J., Koester, D., Marsh, M., Rosen, S., Rutten, R., Sakai, S., Tweedy, R., & Wegner, G. (1995). The orbital period of the pre-cataclysmic binary RE 2013+400 and a study of the atmosphere of the DAO white dwarf primary. \mnras, 272, 531-543.
• Barstow, M., O'Donoghue, D., Kilkenny, D., Burleigh, M., & Fleming, T. (1995). RE 0720-318: a pre-cataclysmic binary system with a DAO white dwarf primary. \mnras, 273, 711-721.
• Fleming, T. A., Molendi, S., Maccacaro, T., & Wolter, A. (1995). The Einstein Extended Medium-Sensitivity Survey Second Epoch: Results for the Stars. The Astrophysical Journal Supplement Series, 99, 701.
• Fleming, T. A., Schmitt, J. H., & Giampapa, M. S. (1995). Correlations of Coronal X-Ray Emission with Activity, Mass, and Age of the Nearby K and M Dwarfs. \apj, 450, 401.
• Hoare, M. G., Barstow, M. A., Werner, K., & Fleming, T. A. (1995). ROSAT observations of EUV-bright planetary nebula central stars. \mnras, 273, 812-820.
• Schmitt, J. H., Fleming, T. A., & Giampapa, M. S. (1995). The X-Ray View of the Low-Mass Stars in the Solar Neighborhood. \apj, 450, 392.
• Barstow, M., Holberg, J., Fleming, T., Marsh, M., Koester, D., & Wonnacott, D. (1994). A ROSAT survey of hot DA white dwarfs in non-interacting binary systems.. \mnras, 270, 499-515.
• Barstow, M., Holberg, J., Marsh, M., Tweedy, R., Burleigh, M., Fleming, T., Koester, D., Penny, A., & Sansom, A. (1994). RE 1738+665: the hottest DA white dwarf detected by ROSAT.. \mnras, 271, 175-182.
• Dempsey, R. C., Linsky, J. L., Fleming, T. A., & Schmitt, J. (1994). The ROSAT All-Sky Survey of Active Binary Coronae. I. Quiescent Fluxes for the RS Canum Venaticorum Systems: Erratum. The Astrophysical Journal Supplement Series, 94, 829.
• Werner, K., Heber, U., & Fleming, T. (1994). Spectral analysis of the hottest known helium-rich white dwarf: KPD0005+5106.. \aap, 284, 907-918.
• Barstow, M., Fleming, T., Diamond, C., Finley, D., Sansom, A., Rosen, S., Koester, D., Marsh, M., Holberg, J., & Kidder, K. (1993). ROSAT studies of the composition and structure of DA white dwarf atmospheres.. \mnras, 264, 16.
• Barstow, M., Fleming, T., Finley, D., Koester, D., & Diamond, C. (1993). ROSAT EUV and soft X-ray studies of atmospheric composition and structure in G 191-B2B.. \mnras, 260, 631-634.
• Dempsey, R. C., Linsky, J. L., Fleming, T. A., & Schmitt, J. (1993). The ROSAT All-Sky Survey of Active Binary Coronae. I. Quiescent Fluxes for the RS Canum Venaticorum Systems. The Astrophysical Journal Supplement Series, 86, 599.
• Dempsey, R. C., Linsky, J. L., Schmitt, J., & Fleming, T. (1993). The ROSAT All-Sky Survey of Active Binary Coronae. II. Coronal Temperatures of the RS Canum Venaticorum Systems. \apj, 413, 333.
• Fink, H., Fleming, T. A., Green, R. F., Jannuzi, B. T., Liebert, J., & Smith, P. S. (1993). Three new BL Lacertae objects in the Palomar-Green Survey. The Astronomical Journal, 106(5), 1729-1733. doi:10.1086/116760
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  We have identified three BL Lacertae objects in the Palomar-Green Survey which were previously misclassified as DC white dwarfs, namely PG 1246+586, PG 1424+240, and PG 1437+398. Our reclassification is based on the detection of these objects as x-ray sources in the ROSAT all-sky survey and upon our subsequent detection of intrinsic linearly polarized and variable optical emission from these sources. As a result of the ROSAT survey, the number of identified BL Lac objects in the Palomar-Green catalog of UV excess objects has been doubled. Corrected optical positions are presented for PG 1246+586 and PG 1437+398.
• Fleming, T. (1993). Recent ROSAT results in stellar X-ray astronomy. Advances in Space Research, 13, 7-13.
• Fleming, T. A., Giampapa, M. S., Schmitt, J., & Bookbinder, J. A. (1993). Stellar Coronae at the End of the Main Sequence: A ROSAT Survey of the Late M Dwarfs. \apj, 410, 387.
• Fleming, T. A., Green, R. F., Jannuzi, B. T., Liebert, J., Smith, P. S., & Fink, H. (1993). Three New BL Lacertae Objects in the Palomar-Green Survey. \aj, 106, 1729.
• Fleming, T. A., Werner, K., & Barstow, M. A. (1993). Detection of the First Coronal X-Ray Source about a White Dwarf. \apj, 416, L79.
• Gudel, M., Schmitt, J. H., Bookbinder, J. A., & Fleming, T. A. (1993). A Tight Correlation between Radio and X-Ray Luminosities of M Dwarfs. \apj, 415, 236.
• Hodgkin, S., Barstow, M., Fleming, T., Monier, R., & Pye, J. (1993). ROSAT/IUE discovery of a white dwarf companion to HD 33959C.. \mnras, 263, 229-235.
• Napiwotzki, R., Barstow, M., Fleming, T., Holweger, H., Jordan, S., & Werner, K. (1993). Analysis of the DA white dwarf HZ 43A and its companion star.. \aap, 278, 478-486.
• Tweedy, R., Holberg, J., Barstow, M., Bergeron, P., Grauer, A., Liebert, J., & Fleming, T. (1993). RE 1016-053: A Pre-Cataclysmic Binary, and the First Extreme Ultraviolet and X-Ray Detections of DAO White Dwarf. \aj, 105, 1938.
• Ayres, T. R., Fleming, T. A., & Schmitt, J. H. (1991). Digging in the Coronal Graveyard: A ROSAT Observation of the Red Giant Arcturus. \apj, 376, L45.
• Fleming, T., Schmitt, J., Barstow, M., & Mittaz, J. (1991). Beta Crateris : another Sirius system in the solar neighborhood.. \aap, 246, L47-L50.
• Pasquini, L., Fleming, T., Spite, F., & Spite, M. (1991). Evidence for strong activity in population II binaries.. \aap, 249, L23-L26.
• Stocke, J. T., Morris, S. L., Gioia, I., Maccacaro, T., Schild, R., Wolter, A., Fleming, T. A., & Henry, J. P. (1991). The Einstein Observatory Extended Medium-Sensitivity Survey. II. The Optical Identifications. The Astrophysical Journal Supplement Series, 76, 813.
• Beuermann, K., Bohringer, H., Danziger, I., Fleming, T. A., Gottwald, M., Hasinger, G., Krautter, J., Macgillivray, H. T., Miller, L., Pakull, M. W., Parker, Q. A., Pasquini, L., Reinsch, K., Thomas, H. C., Trumper, J., Ulrich, M., Voges, W., & Zimmermann, H. (1990). Optical identification content of the ROSAT all sky survey.. The Messenger, 62, 4-6.
• Fleming, T. A., & Giampapa, M. S. (1989). A Search for Chromospheres at Faint Magnitudes. \apj, 346, 299.
• Fleming, T. A., Gioia, I. M., & Maccacaro, T. (1989). The Relation between X-Ray Emission and Rotation in Late-Type Stars from the Perspective of X-Ray Selection. \apj, 340, 1011.
• Fleming, T. A., Gioia, I. M., & Maccacaro, T. (1989). X-Ray-Selected Candidates for the RS CVn and W UMa Classes of Binary Stars. \aj, 98, 692.
• Fleming, T. A., Gioia, I. M., & Maccacaro, T. (1989). X-ray-selected candidates for the RS CVn and W UMa classes of binary stars. The Astronomical Journal, 98, 692. doi:10.1086/115170
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  X-ray luminosity, spectral type, radial-velocity variation, rotationally broadened line profile, and Ca II H and K line emission data are used to identify 12 new candidates for the RS CVn class and seven new candidates for the W UMa class from spectroscopic binaries which are contained in the Einstein Extended Medium Sensitivity Survey. Under the assumption that the candidates are genuine members of each class, local space density estimates of 4.47 + or - 1.19 x 10 to the -4th/cu pc for RS CVn binaries and 8.47 + or - 3.00 x 10 to the -5th/cu pc for W UMa binaries are found. Although the density estimate for the W UMa binaries is shown to be consistent with previous estimates obtained from optically selected samples, the estimate for the RS CVn binaries is more than an order of magnitude greater than previously determined space densities. 40 refs.
• Liebert, J., Green, R., Bond, H. E., Holberg, J., Wesemael, F., Fleming, T. A., & Kidder, K. (1989). A Compact Planetary Nebula around the Hot White Dwarf EGB 6/PG 0950+139. \apj, 346, 251.
• Bergoffen, M. J., Stocke, J., Walter, F., & Fleming, T. A. (1988). IUE Observations of X-Ray Selected Stars. Publications of the Astronomical Society of the Pacific, 100, 736.
• Christou, J. C., Fleming, T. A., Henry, T. J., Liebert, J., Mccarthy, D. W., & Saffer, R. A. (1988). The very low mass triple system - G208-44AB and G208-45. The Astrophysical Journal, 333(2), 943-952. doi:10.1086/166803
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  The nearby (4.7 pc) system G208-44/45 is the closest known stellar triple beyond the Centaurus system. The close astrometric pair 44AB has been resolved using IR speckle interferometry in the JHK bands, yielding individual masses of 0.14 + or - 0.03 solar and 0.10 + or - 0.02 solar for A and B, respectively. The absolute K magnitudes are 8.9 and 10.0, respectively, while the distant component 45 has K = 9.1 and should therefore have a mass slightly below that of 44A. The JHK colors and spectral types are consistent with these values. These results indicate that 44B is the lowest luminosity component known in an astrometric binary and suggest that it could be substellar. Both 44AB and 45 show strong chromospheric H-alpha and Ca II emission. The system kinematics, large implied rotation rate of 44AB, and level of chromospheric activity in the side component suggest a relatively young system.
• Fleming, T. A. (1988). OPTICAL ANALYSIS OF AN X-RAY-SELECTED SAMPLE OF STARS. Publications of the Astronomical Society of the Pacific, 100(631), 1186. doi:10.1086/132287
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  I analyze an X-ray-selected sample of 128 late-type (F-M) stars. These stars were identified as optical counterparts to serendipitous X-ray detections made by the Einstein Observatory Extended Medium Sensitivity Survey. Once identified as X-ray sources, the stars were reobserved with an extensive program of optical observations consisting of highand low-resolution spectroscopy and photometry. Spectral types, luminosity classes, absolute magnitudes, distances, X-ray luminosities, projected rotation rates (v sin i), radial velocities, and binary status have been determined for the sample. I find that Lx is correlated with v sin i for single stars. However, Lx does not correlate with il sin i , which leads me to believe that the correlation seen with v sin i is actually a correlation with radius. Indeed, Lx correlates strongly with radius (color, mass) for main-sequence stars. This result provides a plausibility argument for rotational saturation in the coronae of late-type stars. Since this sample is flux limited, I use sky coverage and sensitivity information from the Einstein Observatory to calculate the bright end of the X-ray luminosity function for late-type stars. It appears that previously-calculated luminosity functions from optically selected samples have underestimated the number of X-ray bright F and G dwarfs. I have also discovered eight previously uncataloged M dwarfs within 25 pc of the Sun. My sample includes only M dwarfs of spectral type M5 and earlier, 93% of which are "emission" stars (i.e., type Me V), as well as two pre-main-sequence M stars. Arguments involving kinematics and stellar rotational velocities are used to estimate the age of these X-ray "bright" M dwarfs; they appear to be quite young (^ 1-3 X 109 yrs). Since the local space density of X-ray "bright" M dwarfs increases with mass, I infer a longer activity time scale for lower masses. M dwarfs later than M5 lie below the X-ray sensitivity limit of the sample. An upper limit of logLx = 27.45 is put on their coronal emission.
• Fleming, T. A. (1988). Optical Analysis of an X-Ray-Selected Sample of Stars. Publications of the Astronomical Society of the Pacific, 100, 1186.
• Fleming, T. A., Grauer, A. D., Green, R. F., & Liebert, J. (1988). THE NUCLEUS OF THE PLANETARY NEBULA VV 47: SIMILARITIES WITH THE PULSATING PG 1159-035/K1-16 VARIABLES. Publications of the Astronomical Society of the Pacific, 100(624), 187-191. doi:10.1086/132154
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  The central star of the planetary nebula VV 47 (164 +31deg1, occasionally known as NGC 2474-5) exhibits an optical spectrum similar to those of the pulsating PG1159-035 stars with somewhat broader absorption lines than those of the pulsating nucleus of the planetary nebula K1-16. Broad absorption features of He II, C IV, and O VI are observed, with narrow emission reversals in some cases. UBV photometry confirms that this is a very hot star, with little reddening. Several long runs of time-series photometry appear to show irregular variations, but we cannot present a conclusive case that this relatively faint object is a pulsating variable. The similarity to the PG1159-035 variables suggests a distance of 1060 (+1000,-600) pc. Our results are consistent with the distance, Zanstra temperature, and luminosity estimates derived by Kaler.
• Fleming, T. A., Liebert, J., Gioia, I. M., & Maccacaro, T. (1988). M Dwarfs from the Einstein Extended Medium-Sensitivity Survey. \apj, 331, 958.
• Liebert, J., Fleming, T. A., Green, R. F., & Grauer, A. D. (1988). The Nucleus of the Planetary Nebula VV 47: Similarities with the Pulsating PG 1159-035/K1-16 Variables. Publications of the Astronomical Society of the Pacific, 100, 187.
• McCarthy Jr., ., Henry, T. J., Fleming, T. A., Saffer, R. A., Liebert, J., & Christou, J. C. (1988). The Very Low Mass Triple System: G208-44AB and G208-45. \apj, 333, 943.
• Bond, H. E., Ciardullo, R., Fleming, T. A., & Grauer, A. D. (1987). The close-binary nucleus of the planetary nebula HFG 1.. Bulletin of the American Astronomical Society, 19.
• Bond, H. E., Fleming, T. A., Grauer, A. D., Green, R. F., & Liebert, J. (1987). A search for pulsating stars similar to PG 1159−035 and K1-16. The Astrophysical Journal, 323(1), 271-279. doi:10.1086/165824
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  Observations photometriques de 15 etoiles pouvant presenter les proprietes de pulsateurs chauds, deficients en hydrogene, tels que PG 1159-035 et le noyau de la nebuleuse planetaire K 1-16
• Fleming, T. A., Gioia, I. M., & Maccacaro, T. (1987). Optical Analysis of an X-ray Selected Sample of Stars. Bulletin of the American Astronomical Society, 19.
• Fleming, T. A., Gioia, I. M., Maccacaro, T., & Mereghetti, S. (1987). 1E 1751 + 7046 - a new FK comae candidate. The Astronomical Journal, 93, 1502. doi:10.1086/114429
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  1E 1751 + 7046 is a star that was serendipitously detected by the Einstein Observatory Medium Sensitivity Survey. X-ray, optical, and radio observations of this star show it to have characteristics similar to the RS CVn binaries. However, repeated high-resolution spectroscopic observations fail to detect any significant radial-velocity variations. The possibility of the star being pre-main-sequence is dismissed because of its location and lack of photospheric Li I. This makes 1E 1751 + 7046 an attractive candidate for the recently proposed class of FK Comae stars. Although there is disagreement over the evolutionary status of these evolved stars, they are nonetheless interesting as exhibitors of extreme chromospheric and coronal activity. 31 references.
• Fleming, T. A., Gioia, I. M., Maccacaro, T., & Mereghetti, S. (1987). IE 1751 + 7046: A New FK Comae Candidate. \aj, 93, 1502.
• Fleming, T. A., Henry, T. J., Liebert, J., Mccarthy, D. W., & Saffer, R. A. (1987). The Second Nearest Triple Sytem: G208-44A/B and G208-45. Bulletin of the American Astronomical Society, 19.
• Grauer, A. D., Bond, H. E., Liebert, J., Fleming, T. A., & Green, R. F. (1987). A Search for Pulsating Stars Similar to PG 1159-035 and K1-16. \apj, 323, 271.
• Fleming, T., Liebert, J., & Green, R. (1986). The Luminosity Function of DA White Dwarfs. \apj, 308, 176.
• Craine, E. R., Culver, R. B., & Fleming, T. A. (1985). OPTICAL IDENTIFICATION OF A SERENDIPITOUS INFRARED SOURCE.. Publications of the Astronomical Society of the Pacific, 97(590), 303-306. doi:10.1086/131535
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  A 30 by 45-arc-min area in the region of an anonymous infrared source discovered near IRAS 0453+444P03 has been examined on near infrared photographs in order to identify very red stars in the vicinity which may be optical counterparts to infrared sources in this area. A list of 15 stars in the region is presented; the list contains the optical counterpart of the anonymous bright, serendipitous infrared source.
• Craine, E., Culver, R., & Fleming, T. (1985). Optical identification of a serendipitous infrared source.. Publications of the Astronomical Society of the Pacific, 97, 303-306.
• Fleming, T. A., Green, R. F., & Liebert, J. (1984). The Luminosity Function of DA White Dwarfs. Bulletin of the American Astronomical Society, 16.

Proceedings Publications

• Barstow, M. A., Bergeron, P., Fleming, T. A., Grauer, A. D., Holberg, J. B., Liebert, J., & Tweedy, R. W. (1993). RE 1016-053 - A pre-cataclysmic binary, and the first extreme ultraviolet and X-ray detections of a DAO white dwarf. In The Astronomical Journal, 105, 1938-1944.
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  Photometric observations and analysis of the optical, UV, EUV, and X-ray spectra are presented for the EUV/X-ray source RE 1016-53. Multiwavelength observations of RE 1016-53 point out that it is a precataclysmic binary. Optical spectra exhibit the steep blue continuum and Balmer absorption typical of a hot white dwarf, but there are bright, narrow emission lines of H I, He I, and Ca II superimposed on this. The white dwarf component, with T (eff) = 55,800 +/- 1000 K and log g = 7.81 +/- 0.007, dominates the spectrum from the optical to the EUV/X-ray. An He II 4686 A absorption line suggests that the white dwarf is a hydrogen-helium (DAO) hybrid star. Four of the five precataclysmic binaries with white dwarfs with T(eff) greater than 40,000 K appear to be DAOs. A mass of 0.57 +/- 0.003 solar mass has been derived.

Others

• Fleming, T. A. (1988, April). Optical Analysis of an X-Ray Selected Sample of Stars..
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  Ph.D. Dissertation