Updated

A New Mexico observatory that was temporarily shut down over an undisclosed security issue is set to reopen Monday after its closure sparked wide-ranging theories, officials said.

The Sunspot Solar Observatory, located near the Sacramento Mountains, no longer faces a security threat to staff, the Association of Universities for Research in Astronomy (AURA) said in a statement Sunday. The facility had been closed since Sept. 6.

“Given the significant amount of publicity the temporary closure has generated, and the consequent expectation of an unusual number of visitors to the site, we are temporarily engaging a security service while the facility returns to a normal working environment,” the statement said.

It’s unclear what the security threat to the observatory was. The FBI referred all questions to the association.

“We recognize that the lack of communications while the facility was vacated was concerning and frustrating for some. However, our desire to provide additional information had to be balanced against the risk that, if spread at the time, the news would alert the suspect and impede the law enforcement investigation. That was a risk we could not take,” officials said.

The temporary closure and reports the FBI was involved sparked wild speculation over the reason.

Otero County Sheriff Benny House told the Alamogordo Daily News the sheriff’s office was asked to stand by and mentioned that the FBI was involved.

“The FBI is refusing to tell us what’s going on,” House told the newspaper. “We’ve got people up there (at Sunspot) that requested us to standby while they evacuate it. Nobody would really elaborate on any of the circumstances as to why. The FBI were up there. What their purpose was nobody will say.”

House said there were a lot of unanswered questions over Sunspot’s closure.

“But for the FBI to get involved that quick and be so secretive about it, there was a lot of stuff going on up there,” House told the newspaper. “There was a Blackhawk helicopter, a bunch of people around antennas and work crews on towers but nobody would tell us anything.”

Security guards from Red Rock Security had been guarding the perimeter of the observatory last week due to the high influx of visitors since word of the facility’s closure, according to the Alamogordo Daily News. A guard told the newspaper at least 35 people had showed up by Friday.

Authorities evacuated all employees from the site, including four from New Mexico State University. About a dozen residents around the site were evacuated and the U.S. Postal Service decided to evacuate employees, too, according to the newspaper.

The Sunspot Solar Observatory is located atop Sacramento Peak and overlooks Tularosa Basin, which includes the city of Alamogordo, Holloman Air Force Base, White Sands Missile Range, and White Sands National Monument.

The telescope at the observatory was originally built by the U.S. Air Force and later was transferred to the National Solar Observatory. The one-of-a-kind telescope produces some of the sharpest images of the sun available to the world.

The Associated Press contributed to this report.