GHOST has returned to service following the successful replacement of the ThAr arc lamp in GCAL. Arc counts have returned to normal, and the instrument will be offered again starting tonight (2025-03-26 UT).
Important information for PIs:
A degradation in the arc lamp was identified beginning around 2025-02-13 UT, which affected the wavelength calibration of data taken during that period.
GHOST is currently unavailable due to the replacement of the ThAr arc lamp. Troubleshooting began on Tuesday, Mar 25, and is still ongoing.
A sudden drop in arc lamp intensity was identified starting on Feb 13, which has continued to decline over time. This degradation has affected the wavelength calibration, introducing uncertainties in the data.
PIs of GHOST programs taken between Feb 13 and now are advised to use arc images acquired before Feb 13 for wavelength calibration.
The 2025B Gemini Observatory Call for Proposals has been released. Proposals are being accepted for observations from 1 August, 2025 to 31 January, 2026. Gemini North and Gemini South are expected to have 128 and 159 nights available for science, respectively. A new version of the Phase I Tool (PIT) has been released to support proposal submissions.
We are pleased to announce that a video tutorial for setting up GHOST Phase II is now available online. Check it out here: https://noirlab.edu/science/videos/ghost
We hope you find it helpful!
The 2025A Gemini Observatory Call for Proposals has been released. Proposals are being accepted for observations from 1 February, 2025 to 31 July, 2025. Gemini North and Gemini South are expected to have 165 and 155 nights available for science, respectively. A new version of the Phase I Tool (PIT) has been released to support proposal submissions.
The 2024B Gemini Observatory Call for Proposals has been released. Proposals are being accepted for observations from 1 August, 2024 to 31 January, 2025. Gemini North and Gemini South are expected to have 153 and 157 nights available for science, respectively. A new version of the Phase I Tool (PIT) has been released to support proposal submissions.
Letters of intent are now solicited for new Gemini Large and Long Proposals, to begin in semester 2024B. Letters are due by February 12 2024, and full proposals by April 1 2024.
We are pleased to present the first GHOST science observations that have been reduced with the GHOST pipeline. We are releasing the spectrum of XX Oph (Be + Red Supergiant; V= 8.59-10.2 mag) as an example to showcase the spectral range, spectral resolution, and overall quality of data that GHOST can provide in standard resolution mode (R=50000; with a total integration time of 240s, and a wavelength range of 347 to 1060nm).
GHOST has not yet been fully commissioned and information such as sensitivities is pending. For this reason GHOST is not offered as an instrument for regular science in 23B. We expect most modes to be fully commissioned late 23A, and for there to be a special Call for proposals in 23B. We will post an announcement as soon as we have more details on the special call in 23B.
After successfully assembling and testing the spectrograph and enclosure from April through June, the team was able to observe with GHOST on-sky for only two good nights at the end of June due to poor weather conditions. A few more good nights in September resulted in further commissioning progress. Presently, the team is working on improving the data deduction pipeline software and the telescope control software to remedy issues determined during these commissioning runs. These improvements are expected to be complete by early 2023.