AstroNote 2021-4

qTNSm is a stand alone command line utility (written in zsh) which queries TNS and downloads classified or unclassified events for requested months in a given year. The output is a tsv file for each requested month with a header line followed by a line records, with one line per event.  A running activity meter is provided (particularly useful when network speed is slow).  The utility written in zsh is robust against usual user mistakes (e.g.  requesting non-existent months or requesting data before 2016 or into the future).  This is an improvement over "QueryTNS_SN" (AstroNote 2020-1) in that the tool can fetch both classified or unclassifid events and more importantly is not limited to 500 records. All records for a given month are extracted by qTNSm.

qTNSm is useful for those undertaking quantitative analysis of events reported to TNS (see, for example, S. R. Kulkarni arXiv:2004.03511).  Unix commands and tools are well suited for tsv files. As such this tool can be useful for pedagogy as well (i.e. assigning homework to students in graduate astronomy courses).

For instance, the header line can be conveniently decoded:

$ sed 1q TNSc_2020_01.tsv | tr '\t' '\n' | nl

     1  "ID"
     2  "Name"
         ...
    22  "Sender"
    23  "Remarks"
    24  "Ext. catalog/s"

Needed columns can be readily extracted as:

$ cut -f2,8 TNSc_2020_01.tsv
...
"SN 2020L"      "0.061762"
"SN 2020K"      "0.092"
"SN 2020G"      ""
"SN 2020E"      ""

The qTNSm shell script is attached.

Possible usage, e.g.:

qTNSm      2021 1       % classified events for Jan, 2021
qTNSm -t u 2021 1      % unclassified events for Jan, 2021
qTNSm      2020 1 2    % classified events for Jan & Feb  2020
qTNSm      2020          % classified events for all of 2020