GALANTE is an optical photometric survey currently being undertaken with the
Observatorio Astrofísico de Javalambre (OAJ) in Teruel, Spain.
Its main characteristics are:
Coverage of the northern Galactic Plane defined by δ > 0o and
|b| < 3o which requires 1005 fields, with seven intermediate+narrow band filters.
The survey also includes some 63 interesting fields outside the main footprint, such as the Orion Nebula, the Pleiades, M31,
and M33 for a total of 1068 fields. Each field is 1.4ox1.4o.
Measurement of the magnitudes of all stars in that region of the sky with AB magnitudes < 17 and a minimum S/N of 70.
Since we want to include all bright stars and our magnitude limit is not too deep, we need to do several short exposures per
field for each filter but not very long exposures. Hence, the survey length is heavily influenced by the overheads
(pointing, readouts, and filter changes).
The observation strategy for each filter is:
- Four exposures of 50 s or 100 s each (long exposures) at two different air masses.
- Two exposures of 10 s each (intermediate exposures).
- Two exposures of 1 s each (short exposures).
- Two exposures of 0.1 s each (very short exposures).
The brightest stars (starting around magnitude 4-5) saturate even in the 0.1 s exposures. In those cases we have checked
that PSF fitting of the profile wings is enough to obtain accurate photometry.
For the long exposures, the fields are observed twice during the night at different air masses to provide a more accurate
photometric calibration and eliminate possible color effects introduced by the atmosphere.
The seven filters used are listed below in order of decreasing central wavelength. Four of them belong to the
J-PLUS dataset and the other three are specific filters designed for this project.
F861M (J-PLUS). This is an intermediate filter in the Calcium triplet window. It will be used to detect the largest
possible number of stars (as the population in our neighborhood is dominated by cool, red objects), to tie the astrometry
and photometry with 2MASS, and to produce (together with F665N) colors for many stars.
F660N (J-PLUS) and F665N (GALANTE specific). These are two narrow-band filters to measure Hα, the first
one including the line and the second one just the continuum. Their purpose is to: [a] measure the red continuum, [b]
estimate gravity by means of the equivalent width of Hα, and [c] flag objects with Hα emission.
F515N (J-PLUS). This is a Strömgren y-like filter in a wavelength region relatively free of lines and a width
of 145 Å. It will be used as the V-equivalent filter for the survey.
F450N (GALANTE specific) and F420N (GALANTE specific). They are probably the most original filters in the
survey. They have been chosen to fill the gaps between Hγ and Hδ and between Hβ and Hγ, respectively.
For most hot stars these are the bluemost regions of the spectrum to the right of the Balmer jump broad enough to fit a
100-200 Å wide filter without interference from strong absorption lines. Therefore, they provide a measurement of the
blue continuum. In combination with other filters they will be used to simultaneously measure the Teff and
the amount of extinction for hot stars. They will also be used to estimate metallicity in cool stars.
F348M (J-PLUS). This is a Strömgren u-like filter that measures the continuum to the left of the Balmer jump.
In combination with F420N and F450N it is needed to measure the Balmer jump and, from there, the Teff of
The three main scientific objectives of GALANTE are:
- The identification of the population of OB stars within a few kpc of the Sun.
- The measurement of the optical dust extinction properties within that region.
- Cataloguing the F and G stars in the solar neighborhood.
In addition, we will also generate a sub-arcsecond map of Hα in the Northern Galactic Plane, produce a
catalog of objects with Hα emission, study the SED distribution of peculiar objects such as AGB stars, and complement
the Gaia information at wavelengths shorter than the Balmer jump and in crowded and nebular regions.
Data Release 1 (April 2021)
The Data Release 1 (DR1) includes 20 different fields from four regions in the sky:
The H II region Berkeley 59 (1 field).
The H II region NGC 2244 (2 fields).
The OB association Cygnus OB2 (3 fields).
A large section of the Galactic plane in Cassiopeia-Perseus (14 fields).
The Berkeley 59 field was already included in DR0 but the data in DR1 has a new calibration. The other 19 fields are new. DR1 includes
three different types of files:
Data Release 0 (July 2020)
The Data Release 0 (DR0) includes the Berkeley 59 field, centered on right ascension of 0.70° and declination of +67.15°
(J2000) took place on 30 June 2020. The field was selected as a representative of a nearby
(d ~ 1.1 kpc) H II region that fits within a single GALANTE field. DR0 includes information for
62 262 stars with AB magnitudes between 5 and 20. In addition, there are three GALANTE images of Berkeley 59 with the
astrometric information embedded in their headers that can be used with Aladin.
Who are we?
The GALANTE team includes researchers that arre currently working on the project from different institutions:
Centro de Astrobiología, Villanueva de la Cañada, Madrid, Spain:
Instituto de Astrofísica de Andalucía, Granada, Spain:
Centro de Estudios de Física del Cosmos de Aragón, Teruel, Spain:
- Héctor Vázquez Ramió
- Jesús Varela
Universidad de La Serena, La Serena, Chile:
European Space Astronomy Centre, Villanueva de la Cañada, Madrid, Spain:
Instituto de Astrofísica de Canarias, San Cristobal de La Laguna, Tenerife, Spain:
Universidade de São Paulo, São Paulo, Brazil:
- Alessandro Ederoclite
- Paula Rodrigues Teixeira Coelho
Previously active members:
- Antonio Marín Franch
- A. Javier Cenarro
- Carlos López San Juan
- Daniel J. Lennon
- Antonio Lorenzo Gutiérrez
- Helena García Escudero