arXiv subjects

Petr Kubánek

Publications and source records attributed to Petr Kubánek.

7 recordsLinked to original sources

arXiv2026

Determining stress-based bending mode limits for the Vera C. Rubin Observatory M1M3 active mirror system

The Vera C. Rubin Observatory Simonyi Survey Telescope's primary-tertiary mirror (M1M3) is an actively supported, 8.4-m cast borosilicate optic controlled by 156 pneumatic actuators. This work presents a rapid stress-estimation methodology based on the root-sum-square (RSS) combination of Finite Element Analysis to derive pre-computed unit bending mode stresses. Since the stress is proportional to strain, and strain is proportional to displacements, we theorized that since the bending mode displacements can be combined RSS, that the peak stresses would also combine by RSS. We validate the RSS-based major principal stress predictions against NASTRAN simulations for representative bending mode combinations, demonstrating agreement within a few percent for peak Principal major stress across the mirror glass substrate. Unit displacement and corresponding unit stress fields for the first 20 natural bending modes of the M1M3 system are generated using NASTRAN. Representative multi-mode corrections including combinations that include astigmatism, coma, and spherical modes of higher order are then analyzed to compare the resulting peak principal stresses with RSS-based predictions. The method enables near instantaneous evaluation of stress margins for active optics corrections, safety-limit checking, and actuator-force optimization during telescope operations. This paper outlines the formulation, implementation workflow, validation results, and practical use cases for integrating RSS-based stress prediction into the Vera C. Rubin Observatory's M1M3 active optics system.

astro-ph.IM↗

arXiv2026

Rubin M1M3 Dynamic performance : stability and actuation during operations

The Vera C. Rubin Observatory is preparing to commence the Legacy Survey of Space and Time with the fully integrated Simonyi Survey Telescope. To verify that the primary/tertiary (M1M3) mirror system is ready to meet the demanding survey requirements, dynamic tests of the 8.4 m, 53 ton M1M3 system were conducted to assess safety, stability, and image quality under realistic operating conditions. The M1M3 is supported by 156 pneumatic force actuators and positioned, relative to its mirror cell, by six hardpoint actuators that together must counteract gravitational and inertial loads during rapid telescope motion. The Rubin Observatory telescope mount is capable of moving at a rate that meets its nominal motion requirements, and can approach it maximum allowable values that are 50 percent higher. Even at just 20 % of its operational speed, it is an exceptionally fast motion for such a large structure. After slewing, the system must stabilize and dampen vibrations within 5 seconds to ensure image quality during observations. Achieving this rapid settling requires precise control of 156 force actuators, which must adjust dynamically with changes in telescope elevation to compensate for gravity effects. We present results for M1M3 from a comprehensive series of TMA dynamical tests spanning the operational envelope of slew velocities and accelerations. The analysis evaluates elevation axis balancing and lookup table updating as we install the M1M3 mirror; slew-and-settle behavior, force response and stability of the pneumatic actuator system across telescope attitudes including responses to the earthquake. The results demonstrate the readiness of the M1M3 subsystem for routine survey operations and provide validation data for ongoing performance modeling.

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arXiv2016

A decade of GRB follow-up by BOOTES in Spain (2003-2013)

This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in the previous article, and are here reviewed, updated, and include additional detection data points as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available.

astro-ph.HE↗

arXiv2010

Scheduling in Targeted Transient Surveys and a New Telescope for CHASE

We present a method for scheduling observations in small field-of-view transient targeted surveys. The method is based on maximizing the probability of detection of transient events of a given type and age since occurrence; it requires knowledge of the time since the last observation for every observed field, the expected light curve of the event, and the expected rate of events in the fields where the search is performed. In order to test this scheduling strategy we use a modified version of the genetic scheduler developed for the telescope control system RTS2. In particular, we present example schedules designed for a future 50 cm telescope that will expand the capabilities of the CHASE survey, which aims to detect young supernova events in nearby galaxies. We also include a brief description of the telescope and the status of the project, which is expected to enter a commissioning phase in 2010.

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arXiv2010

RTS2 - the Remote Telescope System

RTS2 is an open source observatory manager. It was written from scratch in the C++ language, with portability and modularity in mind. Its driving requirements originated from quick follow-ups of Gamma Ray Bursts. After some years of development it is now used to carry tasks it was originally not intended to carry. This article presents the current development status of the RTS2 code. It focuses on describing strategies which worked as well as things which failed to deliver expected results.

astro-ph.IM↗

arXiv2007

GRB 060117: Reverse + forward shock solution

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arXiv2006

The bright optical flash from GRB 060117

We present a discovery and observation of an extraordinarily bright prompt optical emission of the GRB 060117 obtained by a wide-field camera atop the robotic telescope FRAM of the Pierre Auger Observatory from 2 to 10 minutes after the GRB. We found rapid average temporal flux decay of alpha = -1.7 +- 0.1 and a peak brightness R = 10.1 mag. Later observations by other instruments set a strong limit on the optical and radio transient fluxes, unveiling an unexpectedly rapid further decay. We present an interpretation featuring a relatively steep electron-distribution parameter p ~ 3.0 and providing a straightforward solution for the overall fast decay of this optical transient as a transition between reverse and forward shock.

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