  Near-Earth asteroid 2012 DA14 made its closest approach on February 15, 2013,
when it passed at a distance of 27,700 km from the Earth's surface. It was the
first time an asteroid of moderate size was predicted to approach that close to
the Earth, becoming bright enough to permit a detailed study from ground-based
telescopes. Asteroid 2012 DA14 was poorly characterized before its closest
approach. We acquired data using several telescopes on four Spanish
observatories: the 10.4m Gran Telescopio Canarias (GTC) and the 3.6m Telescopio
Nazionale Galileo (TNG), both in the El Roque de los Muchachos Observatory
(ORM, La Palma); the 2.2m CAHA telescope, in the Calar Alto Observatory
(Almeria); the f/3 0.77m telescope in the La Hita Observatory (Toledo); and the
f/8 1.5m telescope in the Sierra Nevada Observatory (OSN, Granada). We obtained
visible and near-infrared color photometry, visible spectra and time-series
photometry. Visible spectra together with color photometry of 2012 DA14 show
that it can be classified as an L-type asteroid, a rare spectral type with a
composition similar to that of carbonaceous chondrites. The time-series
photometry provides a rotational period of 8.95 +- 0.08 hours after the closest
approach, and there are indications that the object suffered a spin-up during
this event. The large amplitude of the light curve suggests that the object is
very elongated and irregular, with an equivalent diameter of around 18m. We
obtain an absolute magnitude of H_R = 24.5 +- 0.2, corresponding to H_V = 25.0
+- 0.2. The GTC photometry also gives H_V = 25.29 +- 0.14. Both values agree
with the value listed at the Minor Planet Center shortly after discovery. From
the absolute photometry, together with some constraints on size and shape, we
compute a geometric albedo of p_V = 0.44 +- 0.20, which is slightly above the
range of albedos known for L-type asteroids (0.082 - 0.405).
