Mexican Sites: San Pedro Martir

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Mexican Sites:San Pedro Martir

Vladimir Vassiliev

Alberto Carramiñana

Rene Ong

San Pedro MartirLocation: Baja California115° 25´ +31° 02´; 2836 m

Seeing: 0.6"

Dark sky (22 mag/arcsec)

Low risk of light pollution

Very large fraction of observable nights / year (80%)

Large area unused

Remote access (San Diego, Ensenada)

Run by Instituto de Astronomía UNAM, San Pedro Martir National Park

Site Score: similar to La Palma & Haleakala

U ≈ 21.5, B ≈ 22.3, V ≈ 21.2

Second darkest – after Mauna Kea- from a recent sample study

Kitt Peak

PalomarMMT

Lowell

NIGHT SKY IN THE DESERT

SPM Night Sky

SPM: General• Dark, low light pollution

prospects, excellent seeing, very good percentage of useful nights.

• Home of 2.1m, 1.5m, 0.84m optical telescopes

• Potential development of large facilities (twin 6.5m project – 2012 timeline).

• Recognized as one of the best Northern sites (short listed for LSST and under study by TMT project).

S1: ~2500 m

S2: ~2740 m

S3: ~2600 m

2800 m

Cerros la Botella Azul (2860 m)

Pico Anónimo (2980 m)

Elevation: 2500 mDistance: 2 miles from the observatoryAccess: next to the observatory roadArea: large and flatVegetation : small

Elevation: 2740 mDistance: <0.5 miles from the observatoryAccess: needs roadArea: limited slightly inclinedVegetation : small

Infrastructure

On the way back

SPM Summary (prelim.)

• Initial research is encouraging• Well developed infrastructure in place• There are several options for VERITAS location• No land purchase involved; most likely lease

charges or tenant use fees.• IA-OAN has indicated interest in scientific and/or

technical benefit from potential collaboration rather than in financial gain.

• Building permit would be required from government agency (Urban Development Department). Cost of permit processing is probably less than $10K. The review process would take a few months.

• There was no precedent of constructing project by foreign country on the state park. Some tax liability might be involved.

• Environmental impact study would be required. Could cost anywhere between 5 and 50K. Having collaborating partner on Mexican side might significantly simplify procedures. Study would require <8 months and will most likely be concerned with alteration of land and vegetation (tree cutting was particularly mentioned).

• The visibility of telescopes to the public will likely be considered as a positive feature.

• Risk of denial of building permit is likely low as the process is handled by governmental agencies; no public notification or hearing seem to be required.

• Construction costs cannot be assessed at this stage but will be lower than in Tucson

• Electricity: there are several on site generators each of which is ~250 KVA. Commercial power grid is 65km away.

• Communication: There is microwave link insufficient for VERITAS data transfer needs. Data will need to be delivered to Tucson on tapes/DVDs or reduced at the site.

• Major disadvantages comparing to Kitt Peak are remote location, lack of high capacity communication link, and possibly lack of commercial power line (is not immediately clear if use of generators is more expensive).

Final CommentSierra Negra site is also a potential candidate

– high elevation dry site; – 97° 18´ +18° 59´; up to 4580 m– seeing: 0.7"– sky brightness measurements in progress– fair fraction of observable nights / year– One mountain site + Citlaltepetl slope site– easy access (1 hr motorway + 1 hr

mountain road from Puebla)– Under development by INAOE– Possibly needs further research

Mexican Sites: San Pedro Martir

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