294 research outputs found
The Snedden-Farnsworth Exchanges of 1917 and 1918 on the Value of Music and Art in Education
In 1917 and 1918, Charles Hubert Farnsworth, a leading music educator from Teachers College, Columbia University, and David Snedden, a critic and educational theorist of national repute, privately exchanged views on the role of art and music in society and in education. Snedden mulled over Herbert Spencer's query “What knowledge is of most worth?” and concluded that music must have practical survival value: it must contribute primarily to the maintenance of social and political order and secondarily to other aims. Farnsworth, on the other hand, thought that music performance or appreciation should be for the immediate joy that it gives the individual, not for some deferred social purpose no matter how important it might be. These divergent positions are explained in light of Farnsworth's interests in philosophy and Snedden's schooling in Spencerian and Darwinian thought.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68979/2/10.2307_3345173.pd
The Hercules-Aquila Cloud
We present evidence for a substantial overdensity of stars in the direction
of the constellations of Hercules and Aquila. The Cloud is centered at a
Galactic longitude of about 40 degrees and extends above and below the Galactic
plane by at least 50 degrees. Given its off-centeredness and height, it is
unlikely that the Hercules-Aquila Cloud is related to the bulge or thick disk.
More likely, this is a new structural component of the Galaxy that passes
through the disk. The Cloud stretches about 80 degrees in longitude. Its
heliocentric distance lies between 10 and 20 kpc so that the extent of the
Cloud in projection is roughly 20 kpc by 15 kpc. It has an absolute magnitude
of -13 and its stellar population appears to be comparable to, but somewhat
more metal-rich than, M92.Comment: ApJ (Letters), in pres
A Strategy for Finding Near Earth Objects with the SDSS Telescope
We present a detailed observational strategy for finding Near Earth Objects
(NEOs) with the Sloan Digital Sky Survey (SDSS) telescope. We investigate
strategies in normal, unbinned mode as well as binning the CCDs 2x2 or 3x3,
which affects the sky coverage rate and the limiting apparent magnitude. We
present results from 1 month, 3 year and 10 year simulations of such surveys.
For each cadence and binning mode, we evaluate the possibility of achieving the
Spaceguard goal of detecting 90% of 1 km NEOs (absolute magnitude H <= 18 for
an albedo of 0.1). We find that an unbinned survey is most effective at
detecting H <= 20 NEOs in our sample. However, a 3x3 binned survey reaches the
Spaceguard Goal after only seven years of operation. As the proposed large
survey telescopes (PanStarss; LSST) are at least 5-10 years from operation, an
SDSS NEO survey could make a significant contribution to the detection and
photometric characterization of the NEO population.Comment: Accepted by AJ -- 12 pages, 11 figure
Discovery of an Unusual Dwarf Galaxy in the Outskirts of the Milky Way
In this Letter, we announce the discovery of a new dwarf galaxy, Leo T, in
the Local Group. It was found as a stellar overdensity in the Sloan Digital Sky
Survey Data Release 5 (SDSS DR5). The color-magnitude diagram of Leo T shows
two well-defined features, which we interpret as a red giant branch and a
sequence of young, massive stars. As judged from fits to the color-magnitude
diagram, it lies at a distance of about 420 kpc and has an intermediate-age
stellar population with a metallicity of [Fe/H]= -1.6, together with a young
population of blue stars of age of 200 Myr. There is a compact cloud of neutral
hydrogen with mass roughly 10^5 solar masses and radial velocity 35 km/s
coincident with the object visible in the HIPASS channel maps. Leo T is the
smallest, lowest luminosity galaxy found to date with recent star-formation. It
appears to be a transition object similar to, but much lower luminosity than,
the Phoenix dwarf.Comment: Ap J (Letters) in press, the subject of an SDSS press release toda
Light and Motion in SDSS Stripe 82: The Catalogues
We present a new public archive of light-motion curves in Sloan Digital Sky
Survey (SDSS) Stripe 82, covering 99 deg in right ascension from RA = 20.7 h to
3.3 h and spanning 2.52 deg in declination from Dec = -1.26 to 1.26 deg, for a
total sky area of ~249 sq deg. Stripe 82 has been repeatedly monitored in the
u, g, r, i and z bands over a seven-year baseline. Objects are cross-matched
between runs, taking into account the effects of any proper motion. The
resulting catalogue contains almost 4 million light-motion curves of stellar
objects and galaxies. The photometry are recalibrated to correct for varying
photometric zeropoints, achieving ~20 mmag and ~30 mmag root-mean-square (RMS)
accuracy down to 18 mag in the g, r, i and z bands for point sources and
extended sources, respectively. The astrometry are recalibrated to correct for
inherent systematic errors in the SDSS astrometric solutions, achieving ~32 mas
and ~35 mas RMS accuracy down to 18 mag for point sources and extended sources,
respectively.
For each light-motion curve, 229 photometric and astrometric quantities are
derived and stored in a higher-level catalogue. On the photometric side, these
include mean exponential and PSF magnitudes along with uncertainties, RMS
scatter, chi^2 per degree of freedom, various magnitude distribution
percentiles, object type (stellar or galaxy), and eclipse, Stetson and Vidrih
variability indices. On the astrometric side, these quantities include mean
positions, proper motions as well as their uncertainties and chi^2 per degree
of freedom. The here presented light-motion curve catalogue is complete down to
r~21.5 and is at present the deepest large-area photometric and astrometric
variability catalogue available.Comment: MNRAS accepte
LOTIS, Super-LOTIS, SDSS and Tautenburg Observations of GRB 010921
We present multi-instrument optical observations of the High Energy Transient
Explorer (HETE-2)/Interplanetary Network (IPN) error box of GRB 010921. This
event was the first gamma ray burst (GRB) localized by HETE-2 which has
resulted in the detection of an optical afterglow. In this paper we report the
earliest known observations of the GRB010921 field, taken with the 0.11-m
Livermore Optical Transient Imaging System (LOTIS) telescope, and the earliest
known detection of the GRB010921 optical afterglow, using the 0.5-m Sloan
Digital Sky Survey Photometric Telescope (SDSS PT). Observations with the LOTIS
telescope began during a routine sky patrol 52 minutes after the burst.
Observations were made with the SDSS PT, the 0.6-m Super-LOTIS telescope, and
the 1.34-m Tautenburg Schmidt telescope at 21.3, 21.8, and 37.5 hours after the
GRB, respectively. In addition, the host galaxy was observed with the USNOFS
1.0-m telescope 56 days after the burst. We find that at later times (t > 1 day
after the burst), the optical afterglow exhibited a power-law decline with a
slope of . However, our earliest observations show that
this power-law decline can not have extended to early times (t < 0.035 day).Comment: AASTeX v5.x LaTeX 2e, 6 pages with 2 postscript figures, will be
submitted to ApJ Letter
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