Did Malik-Shah construct an observatory in Merv in 1073?

[Temüjin]

I've come across references to this mostly in articles that focus on the life of Omar Khayyam. However i cannot find any reference to this in sources detailing with observatories in the Islamic world (article by Micheau for example), and is only rarely found in general articles on Malik-Shah or Merv, and never in connection with the Seljuq empire.

Considering that the construction of an observatory was kind of a big deal in the middle ages, such as the obersvatory constructed at Maragheh by the Il-Khanids, this would be significant.

[H. İhsan Erkoç]

I also don't remember reading anything about Seljuk observatories. Constructing observatories seem to be something of an Ilkhanid and Timurid thing.

[Temüjin]

yes, i'm not aware of any observatory-building in between the ones constructed during the golden age of the abbasids and the subsequent buyids plus the famous failed attempts of the fatimids to do so, and the later famous observatories of the il-khanids and timurids. i also read that merv supposedly had a pre-islamic observatory, which i couldn't verify either...

in regards to the seljuqs, the well-known vizier nizam ul-mulk was known to construct madaris in several cities, including merv. i think it would have been better recorded if there was indeed an attempt to construct a true observatory for or by omar khayyam...