AMBER - Astronomical Multi-BEam combineR


AMBER, Courtesy of AMBER Consortium
Image courtesy of the AMBER Consortium.

AMBER, the near-infrared/red focal instrument of the VLTI, operates in the bands J, H, and, K (ie 1.0 to 2.4 μm). The instrument has been designed to be used with two or three beams, thus enabling also the use of closure phase techniques. The magnitude limits of AMBER are K=7 with Low Resolution (LR-HK) on UTs and K=5 on the ATs, K=4 with Medium Resolution K-band (MR-K) on the UTs and K=1.6 on the ATs, and K=1.5 with High Resolution K-band (HR-K) on UTs.

Using AMBER with an external fringe tracker (FINITO, now available in P81 on the ATs) it is possible to reach K=5 and H=5 in all modes ie for LR-KH, MR-K and HR-K under optimal weather conditions ie Seeing ≤0.6" and Coherence time ≥3ms. For 0.6"<Seeing≤0.8" the limit is K=4 and H=4, and for 0.8"<Seeing≤1.2" the limit is K=3 and H=3. Depending on the required limiting magnitudes the user should request the proper weather constraints.

Below is a table showing the a summary of the absolute pre requisites for a target to be able to observe it with AMBER in Service Mode

Absolute Pre-requisites for AMBER in service mode

Mode is the Spectral Configuration, Kcorr and Hcorr the correlated magnitudes in K and H, VisK and VisH the K and H lowest visibility on the two shortest baselines, AM the Airmass of the target, Vmag the magnitude in the Visible of the guide star and Dist is the distance from the science object and the guide star.
Configuration Absolute Pre-requisites
Mode Tel FINITO Kcorr Hcorr VisK VisH AM Vmag Dist
[magnitude] [magnitude]       [magnitude] [arcsec]
LR UT no ≤7 ≤7 ≥0.1 ≥0.1 ≤2.0 1...17 ≤57.5
MRK UT no ≤4   ≥0.1   ≤2.0 1...17 ≤57.5
HRK UT no ≤1.5   ≥0.1   ≤2.0 1...17 ≤57.5
LR AT no ≤5.1 ≤5.5 ≥0.05 ≥0.05 ≤2.0 -1.7...13.5 ≤60
MRK AT no ≤1.6   ≥0.05   ≤2.0 -1.7...13.5 ≤60
HRK AT no Not offered on the ATs without FINITO
LR UT yes FINITO not offered on the UTs
MRK UT yes FINITO not offered on the UTs
HRK UT yes FINITO not offered on the UTs
LR AT yes ≤5 ≤5 ≥0.05 ≥0.15 ≤1.5 -1.7...13.5 ≤60
MRK AT yes ≤5 ≤5 ≥0.05 ≥0.15 ≤1.5 -1.7...13.5 ≤60
HRK AT yes ≤5 ≤5 ≥0.05 ≥0.15 ≤1.5 -1.7...13.5 ≤60


Publications based on data obtained with the AMBER instrument should quote the following reference paper:
Petrov, R.G., et al. AMBER, the near-infrared spectro-interferometric three-telescope VLTI instrument, 2007, A&A, Vol. 464, Issue 1, pp.1-12.

Key People Involved

Built under ESO contract by: AMBER Consortium
Principal Investigator Romain Petrov (Nice, France)
Project Scientist Fabien Malbet (LAOG, Grenoble, France)
Instrument Scientist (Garching): Andrea Richichi
Instrument Scientist (Paranal): Fredrik T Rantakyrö, Stan Stefl
Instrument Software Support: Andres Ramirez
Instrument Hardware Support: Pedro Mardones

Contact Information

  • Questions related to service mode observations and proposal preparation should be addressed to the User Support Department.
  • Questions related to visitor mode observations should be addressed to Paranal Science Operations
  • Please send us your comments, suggestions and report errors and inaccurate statements in the web pages and manuals.

Content of these pages

The following items are available on all the AMBER pages, using the bar on the left.
  • News: list of changes affecting the instrument and/or its pages.
  • Overview: a short description of the instrument
  • Instrument Description: all the important parameters of the instrument.
  • Manuals: links to all the documents related to AMBER.
  • Tools: a collection of useful tools and informations for preparing and analyzing the AMBER observations.
  • Instrument Operations Team
  • Links: miscellaneous links about interferometry and AMBER.
  • Visitor Instructions: Instrument specific instructions for Visiting Astronomers
  • Consortium: A list of the AMBER Consortium contributing Institutes.
You're on EPU
View live page