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[Second Report] Cancellation and carrying over of the observations in Season 2016-2017

It is quite regret to inform that all the observations with the T70, TZ, and FOREST receivers in this observing season (Season 2016-2017) have to be cancelled due to the malfunction of the master collimator driving system, and these observations will be carried over to the next observing season (Season 2017-2018). Observations with the H22, H40, and Z45 receivers can be carried out.

As the previous announcement on 30th March 2017, observations of the 45-m Telescope have been suspended due to the malfunction of the master collimator driving system. The observatory and the manufacturer had investigated this issue, and serious damages were found at gears and bearings in the master collimator driving system. It will take more than 4 months to repair. The observatory had also investigated the pointing accuracy without the master collimator, and found that the pointing error is as large as 20 arcsec (peak-to-peak), which is comparable to the beam size (20 arcsec) at 86 GHz, in a short timescale.

The observatory decide to cancel the remaining observations with the T70, TZ, and FOREST receivers, and carry over to the next observing season (Season 2017-2018) based on the intention of each PI. The remaining observations with the H22, H40, and Z45 receivers will be allocated in this season (Season 2016-2017) with the confirmation of each PI. If PI does not intent to observe in this season, his/her observation will be allocated in the next observing season based on the intention of each PI. Please note that the observing time in the next season will be allocated from November 2017 - March 2018.

17th April 2017

Acting director of Nobeyama Radio Observatory
Hideyuki Kobayashi

[Initial Report] Observations are suspended due to a malfunction of the master collimator driving system

The master collimator of Nobeyama 45-m telescope is out of order. Azimuth drives of this master collimator have a problem in gearboxes and enough tracking accuracy cannot be achieved any more, and all scientific observations are suspended at present. The master collimator system was introduced because high pointing accuracy beyond 3 arcsecond degree are necessary for an observation at 110GHz by Nobeyama 45-m telescope. Currently it is difficult to keep this accuracy.

From 4th March, tracking errors have begun to occur in the followed usual state. Nobeyama radio observatory had tried to recover it, but from 17th March, it became completely out of order. A manufacturer of the telescope, Mitsubishi Electric Corporation, was called for a broken investigation. We have reported this situation to all PIs of following observations. And the observatory has proceeded the tracking accuracy measurements without the master collimator and tried to start the low frequency observations.

30th March 2017

Acting director of Nobeyama Radio Observatory
Hideyuki Kobayashi