Zobrazeno 1 - 10
of 17
pro vyhledávání: '"Walker, Alistair R."'
Autor:
Terndrup, Donald M., An, Deokkeun, Hansen, Angela, Peterson, Ruth C., Walker, Alistair R., Sadler, Elaine M.
Publikováno v:
Astrophys.Space Sci.291:247-252,2004
We present a progress report on an extensive survey to find and characterize all types of blue horizontal-branch stars in the nuclear bulge of the Galaxy. We have obtained wide, shallow imaging in UBV of ~12 square degrees in the bulge, with follow-u
Externí odkaz:
http://arxiv.org/abs/astro-ph/0309700
Autor:
Walker, Alistair R.
Publikováno v:
Mem.Soc.Ast.It. 74 (2003) 999-1003
The Large Synoptic Survey Telescope (LSST) is conceived as an 8.4-m telescope with CCD or CMOS focal plane covering most of a field 0.6 m in diameter, the latter exceeding the size of the largest photographic plates ever used in astronomy. The telesc
Externí odkaz:
http://arxiv.org/abs/astro-ph/0303012
Autor:
Walker, Alistair R.
Publikováno v:
Lect.Notes Phys. 635 (2003) 265-279
Distances to galaxies in the Local Group are reviewed. In particular, the distance to the Large Magellanic Cloud is found to be $(m-M)_0 = 18.52 \pm 0.10$, corresponding to $50,600 \pm 2,400$ pc. The importance of M31 as an analog of the galaxies obs
Externí odkaz:
http://arxiv.org/abs/astro-ph/0303011
We present the first results of a survey of blue horizontal branch (BHB) stars in the Galactic bulge. 164 candidates with 15 < V < 17.5 in a field 7.5deg from the Galactic Center were observed in the blue at 2.4A FWHM resolution with the AAT 2dF spec
Externí odkaz:
http://arxiv.org/abs/astro-ph/0004271
Autor:
Walker, Alistair R.
We present a deep color magnitude diagram for the galactic globular cluster NGC 2808 (C0911-646), reaching 3 magnitudes below the main sequence turnoff. A set of local photometric standards are provided, and the mean cluster reddening and metallicity
Externí odkaz:
http://arxiv.org/abs/astro-ph/9904387
Autor:
Suntzeff, Nicholas B., Walker, Alistair R., Smith, Verne V., Kraft, Robert P., Klemola, Arnold, Stetson, Peter B.
We present both low and high-dispersion abundance analyses of giants drawn from the zero proper motion sample near NGC 121. For the sample of 35 stars, the mean metallicity of the SMC field near NGC 121 is [Fe/H]=-1.3 with a real dispersion of 0.4 de
Externí odkaz:
http://arxiv.org/abs/astro-ph/9809358
Autor:
Walker, Alistair R.
The present status of our knowledge of the distances to the Magellanic Clouds is evaluated from a post-Hipparcos perspective. After a brief summary of the effects of structure, reddening, age and metallicity, the primary distance indicators for the L
Externí odkaz:
http://arxiv.org/abs/astro-ph/9808336
Autor:
Walker, Alistair R.
The variable star population of the galactic globular cluster NGC 1851 (C0512-400) has been studied by CCD photometry, from observations made in the B, V, and I bands during 1993-4. Light curves are presented for 29 variables, seven of which are new
Externí odkaz:
http://arxiv.org/abs/astro-ph/9804339
Autor:
Lira, P., Suntzeff, Nicholas B., Phillips, M. M., Hamuy, Mario, Maza, Jose, Schommer, R. A., Smith, R. C., Wells, Lisa A., Aviles, R., Baldwin, J. A., Elias, J. H., Gonzalez, L., Layden, A., Navarrete, M., Ugarte, P., Walker, Alistair R., Williger, Gerard M., Baganoff, F. K., Crotts, Arlin P. S., Rich, R. Michael, Tyson, N. D., Dey, A., Guhathakurta, P., Hibbard, J., Kim, Y. -C., Rehner, Daniel M., Siciliano, E., Roth, Joshua, Seitzer, Patrick, Williams, T. B.
We present UBVRI light curves for the bright Type Ia supernovae SN 1990N in NGC 4639 and SN 1991T in NGC 4527 based on photometry gathered in the course of the Calan/Tololo supernova program. Both objects have well-sampled light curves starting sever
Externí odkaz:
http://arxiv.org/abs/astro-ph/9709262
The CTIO Prime Focus CCD instrument with an RCA CCD was in operation at the CTIO 4-m telescope for six years between 1982-1988. A large body of literature has been published based on CCD images taken with this instrument. We review the general proper
Externí odkaz:
http://arxiv.org/abs/astro-ph/9601010