PST1 > Description

Table of contents (hide)

  1. 1. Design
  2. 2. Test spectra
  3. 3. Spectrograph stability tests
  4. 4. History

1.  Design

Poznań Spectroscopic Telescoope 1 (PST1) was designed as a small but quantum-efficient spectroscope producing medium-high resolution spectra. It consists primarily of:

  • binary 2x0.5m Newtonian telescope
  • fibre-fed echelle spectrograph of resolution R~35000
  • low noise back-illuminated 2k x 2k Andor DZ 436 CCD camera
PST1 housing
Schematic drawing of PST1 housing.
FIU - fiber injection unit, CCR - computer control room,
SR - spectrograph room, OTA - binary Newtonian telescope.

The telescope sits on equatorial, robotic mount and is capable of performing remotely controlled observations. Because it is composed of two parallel 0.5m OTAs it may be used in several different modes. In basic mode only single mirror is used for spectroscopy. In second mode both mirrors will be used to produce two simultaneous echelle spectra of the same object. Such a parallel spectra may be used to increase S/N ratio or help to discriminate cosmic rays. Third mode allows for simultaneous photometric and spectroscopic observations.

Results of radial velocity measurements done with Poznań Spectroscopic Telescoope 1 (PST1) so far show a stability at a level of 100 m/s. This corresponds to about ~1/25 of our CCD pixel size (13.5 microins). Thanks to its light-efficient design and low noise camera we are able to achieve S/N~100 for V=7 stars with 60 min. exposure time. This means that we can precisely measure radial velocities for late type stars up to about 11.5 mag.

Spectrograph scheme
PST1 echelle spectrograph scheme.

PST1 was designed to fit a fibre-fed echelle spectrograph of a medium resolution of 35000. The spectrograph optical construction is based on a modified MUSICOS design with a rotating carousel removed and only one fixed prism being used. The spectral range covers 64 echelle orders with wavelength from 4500 Å to 9200 Å or 56 orders in configuration from 4280 Å to 7500 Å.

2.  Test spectra

Tungsten lamp
Tungsten lamp in configuration with 64 echelle orders. Click to zoom .
Th-Ar lamp
Th-Ar calibration lamp in configuration with 64 echelle orders. Click to zoom.
Aldabaran spectrum
Aldabaran spectrum in configuration with 64 echelle orders. Click to zoom.

3.  Spectrograph stability tests

ThAr stability test
Relative changes of Th-Ar calibration spectrum radial velocity is reflecting the spectrograph thermal drift in 2008.
ThAr stability test
Relative changes of Th-Ar calibration spectrum radial velocity show no systematic drift in 2010 due to our new thermal stabilisation system. Some residual drift caused by atmospheric pressure changes was visible during other nights.

4.  History

2017 - New CCD for the astrometry of artificial Earth's satellites installed on the telescope
2016 - Telescope control software upgrade
2016 - Weather station and allsky camera installed
2016 - First optical observations of artificial Earth's satellites
2016 - Fully remote spectroscopic observations
2014 - New software for spectroscopic camera
2009 - A new dedicated reduction pipeline
2009 - First photometric observations on both mirrors
2008 - First tests with an iodine cell
2008 - The 0.4m mirrors replaced with 0.5m.
2008 - First year of operation - 1800 spectra
2007 - First light of a new binary telescope
Early stages of the project
2003 - First light (tests on 0.4m photometric telescope)
2003 - First solar spectrum
2002 - Construction of the echelle spectrograph
Page last modified on February 22, 2017, at 11:32 AM