Important recent changes (since Period 101) regarding La Silla Instrumentation and Facilities

This section describes important changes which took place during Period 101 and 102, as well as changes expected to take place during Period 103.

Total solar eclipse

The total solar eclipse visible from La Silla on 2 July 2019 at 20:40UT offers the opportunity for unique observations. Proposals for the NTT only are solicited for this unique event. Approved proposals will go through a thorough feasibility assessment in order to guarantee the safety of the telescope and instruments. Interested users should contact opo@eso.org and lasilla@eso.org well before the proposal submission deadline.

Seeing and Image Quality:

  • The seeing information to be provided in Box 3 of the proposal form is the seeing in the V band at zenith. This ensures that the scheduling tool uniformly takes the seeing into account. Service mode users for approved programmes will enter the Image Quality for the airmass and wavelength of interest required for their observations as a constraint during Phase 2. The article by Martinez et al. 2010 (The ESO Messenger 141, 5) "On the Difference between Seeing and Image Quality" describes the meaning of these two quantities and further information can be found on the Observing Conditions webpage.
  • The Exposure Time Calculators have been changed accordingly and clearly distinguish between the two quantities, using a slightly modi fied version of the formula given in the above article. The ETCs also report on the probability to achieve the input seeing conditions and the resulting image quality.

Exposure Time Calculators:

Instruments and Facilities

  • HARPS: Regular operations with the Laser Frequency Comb are expected to become possible during Period 102. Availability of the Laser Frequency Comb and instructions for its use will be announced in the instrument News page.
  • ULTRACAM:
    • ULTRACAM is a high-speed imaging photometer designed to study faint astronomical objects at high temporal resolutions. ULTRACAM employs two dichroic beamsplitters and three frame-transfer CCD cameras to provide optical imaging with a field-of-view of 60 and at frame rates of up to 300 Hz simultaneously in the u'g'r', u'g'i' or u'g'z' bands.
    • This PI instrument is o ffered to the ESO community for up to 5% of the observing time at the NTT in Period 103. Large Programmes will not be accepted.
    • Operation of this PI instrument requires the presence of the instrument team, so ULTRACAM programmes will preferentially be scheduled contiguously on periods of several nights. For questions on the instrument and observation strategies, users shall contact the instrument PI, Prof. Vik Dhillon (vik.dhillon[AT]sheeld.ac.uk), at least two weeks prior to submitting their proposal.
    • The ULTRACAM consortium is committed to support the PIs and observers from the ESO community that have been awarded telescope time with ULTRACAM. The ULTRACAM team will support the execution of the observations and the subsequent data reduction to allow the scienti c exploitation of the data obtained with ULTRACAM.
    • Proposers must check that their planned observations do not duplicate any protected targets speci fied for ULTRACAM in the Period 103 GTO target protection webpages.