Following up on the interstellar asteroid
‘Oumuamua (see the January 2018 issue of
GeminiFocus, page 4) kept us busy and ex-
cited. ‘Oumuamua was discovered during
an ‘Alopeke commissioning run, and we’re
grateful to the ‘Alopeke team for bearing with
us while we overrode their time to catch this
extraordinary and unprecedented event; this
sacrifice enabled Gemini to help characterize
the peculiar properties of this exotic visitor.
‘Alopeke commissioning was, incidentally,
completed, despite this interruption.
Chile
Early 2017B brought with it the LIGO gravi-
tational wave event whose source Gemini
South brought into focus, capturing early
optical and infrared light from this merger
of two neutron stars (see the October 2017
issue of GeminiFocus, page 7). This exciting
first-time event kept staff busy for a couple
of weeks and required delaying some reme-
dial work on FLAMINGOS-2; this was scien-
tifically well worth it, as we used the instru-
ment to produce some compelling infrared
spectroscopy that confirmed the nature of
the event’s afterglow. See more on FLAMIN-
GOS-2, below.
While the first part of the semester present-
ed some weather issues, the second brought
much better weather, so we were able to
catch up on the Band-1 programs and bring
the completion rate back to reasonable lev-
January 2019 / 2018 Year in Review
els. Late in the semester we received a re-
markable number of Target of Opportunity
(ToO) triggers: in January alone, there were
31 triggers, peaking at four on a single day.
Figure 21 shows the number of nights on
which Gemini South responded to a ToO re-
quest per month (left: Standard ToOs; right:
Rapid ToOs). Most of the variation, and in
particular the end of the semester bump,
was due to Rapid, rather than Standard, ToO
triggers (the peak in August was due to the
LIGO gravitational wave event).
We had frequent visiting observers in the
South as well: among them four conducted
Priority Visitor runs, and visiting Korean as-
tronomers occupied two time blocks. We
also received Phoenix at the telescope as a
visiting instrument late in 2017.
FLAMINGOS-2’s on-instrument wavefront
sensor (OIWFS) continued to generate me-
chanical problems, and we had planned an
intervention early in the semester. As men-
tioned above, the LIGO gravitational wave
event caused us to delay repairs, which we
completed late in 2017. Multi-Object Spec-
troscopy (MOS) commissioning of FLAMIN-
GOS-2 was delayed (as the MOS relies on
the OIWFS) but is now underway. Finally, the
Gemini Multi-conjugate adaptive optics Sys-
tem/Gemini South Adaptive Optics Imager
operation profited greatly from the new
TOPTICA laser.
GeminiFocus
Figure 21.
The number of nights
on which Gemini South
responded to a Standard
ToO request (left) and a
Rapid ToO request (right).
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