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Polarimetry of exotic transients

60-027 Leloudas


This program aims to characterise exotic and unusual transient phenomena by the aims of polarimetry. Polarimetry is a powerful diagnostic tool to study spatially unresolved sources and the polarisation degree is related to the geometry of the transient's photosphere. By constructing polarimetric light curves of unusual transients, such as superluminous supernovae, tidal disruption events or fast transients, we will place important constraints on the explosion physics and emission mechanisms of these elusive events.

Type of observations:

The observing mode is imaging polarimetry with ALFOSC in one or multiple filters. In almost all cases we will request linear polarimetry requiring the lambda/2 retarder plate in the FAPOL unit that is always mounted in ALFOSC.  In rare cases, we might request circular polarimetry, provided that lambda/4 is mounted (after agreement with the telescope staff). We expect to obtain between 5-8 epochs/data points for 2 different transient in 1-4 filters (predominantly V-band but also BRI if possible).   


We request standard bias and flats obtained with the same setup (e.g. window, binning, filter) as the science frames.

Observing conditions:

As this is a ToO we do not have strict constraints on the observing conditions and the observations can be executed in any lunar phase. In case we have specific constraints (e.g. seeing limit) for a particular observation this will be specified in the trigger email and the OB constraints.

Observing instructions:

The OB group to be observed on any night will appear in the Queue as a time-critical group.
  • In a sequencer window type cd ~/scripts/59-013/

  • In this directory you will find the OB compiled script for each night, Run the script within the requested UT window.
    if the script is not available, please compile it from the OB Queue. In the OB Queue the OB groups to be observed on the current date will be high-lighted with an orange colour.

  • Execute the OB. The OB will point the telescope, obtain an acquisition image and the requested science frames. Please check you can recognise the field by comparing it with the Finding Chart. It will be appreciated if you check that the target (marked in the finding Chart) is not saturated in the observations. If so, please repeat by reducing the exposure time accordingly.


The PI will send the target and observing information when this ToO is triggered.

Program Tracking
Proposal 60-027
Semester P60: 20191001 - 20200401
Principal Investigator Giorgos Leloudas
Programme Polarimetry of exotic transients
Instrument ALFOSC
Time Allocation 1 hard trigger, max 45min, possibly 5 obs in 4 hr (soft)
Total Nights 8h
Type ToO+SoftToO
Notes Soft ToO during Nordic service or Technical nights
Total Time Spent 00:52 (hh:mm)
Proposal Date Time Type Targets Files Comments Status
60-027 2020-01-17 00:52 ToO SN2019szu_impola_v_1 ALDa170033 - ALDa170037 Observed by Hans Deeg. Observed


The above information is collected from the ToO/Mon reports that have been created by the observer.

Should any of the observations have been carried out using the OB system, you will find additional information HERE

Back to top Last modified: November 23 2019