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ecsnoopy 3.0 tutorial
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Tutorial ecsnoopy

Version 3.0

Parameter files

Instrument parameter files can be splitted (typically grouped by site). They need to have the extension .instr   (replace snoopy.default). Example.

TBD: default *.instr need to be verified/updated. See with eclist

Photometric zero point can be also splitted in separate files. Extension .zp (replace photo.log). Example

If not available for given instrument, assume ZP=21 and ignore color term correction

Extinction coefficients can also be splitted in separate files. Extension .kext (replace extinction.dat). Example

If not available for given site, skip extinction correction.

Parameter files are searched with the following order:

  1. script directory (.../ecsnoopy/ecsnoopy/instr for .instr,.zp,.kext)
  2.  user directory identified with the shell variable snprivate (eg. for bash export snprivate=/home/enrico/mysnoopypar/ )
  3.  your current working directory


Special keywords:

If a keyword saturat and/or datamin is included in the fits file header, its value will supersedes that in the *.instr file

Target list 

SN coordinate(s) file can contain many objects including multiple objects in the field and multiple fields. One object per line identified by a name. Additional target(s) in the same line are intended as SN companion star(s). Example


The package adopts sextractor,ds9,iraf,fits image index convention (first pixel 1,1). Photutils and WCS adopt python index convention (first pixel 0,0).

Command list

ecsnoopy                    print this common list

eclist                         list and select files

---  Prepare images

ecmjd                          Compute MJD and update file keyword

ecastrometry             Astrometry with scamp

ecastronet                          Astrometry with astronet

ecseeing                        Measure seeing

ecmask                         Build mask for bright stars (used by ecsndiff)

ecdither                       Combine dithered images.

eccosmics                   Cosmic rays correction (TBD)

---  Measure SN mag

ecsnfit                        SN psf fit: run ecpsf, ecfit, ecart on list of images

ecsndif                        Produce image difference and measure SN mag with psf fit

ectemplate                 Download templates for given position from PS1, ZFT, SkyMapper,


---  Calibration

ecph                           Measure standard field and derive zero points

ecrefstar                      Calibrate local reference stars

eczp                           Measure photometric zero point with reference to local or remote


ecsncal                        Derive SN (and companion stars) apparent magnitude

---  Service

ecfindingchart                 Create finding chart with identification of local standards (TBD)

Basic tutorial

Help on command: add -h,  

extended execution log (useful for debug) is provided with  - - debug

Image list: all command works with image list. They can be either a list  in a file (@nomefile) or line list (eg. sc1,sc2,sc3) or using wildcard (sc\* or “sc*”). .fits extension is optional. .sn,.psf,.res…. Files are skipped.

Minimum run

Images need to have astrometry.

eclist    AS\*                     - in case there are ERROR  they need to be addressed

ecsnfit  AS\* sn.coo          

ecsncal AS\*

Examples and templates

Example of *.instr file.

Section is defined by [TELESCOPE,INSTRUME].

There can be multiple filter keywords, separated by commas.


site:        ASIAGO                    OPTIONAL default extinction coefficient 0. for all bands

saturat:   60000.

ra:            RA

dec:         DEC  

datamin :  0                              OPTIONAL  default INDEF

epadu:     0.9                            OPTIONAL  default 1.0

ron:         7.8                             OPTIONAL  default 4.0

scale:      0.506

object:      OBJECT                  OPTIONAL  

exptime:   EXPTIME

mjd:          MJD

dateobs:   DATE-OBS              OPTIONAL

airmass:   AIRMASS                OPTIONAL  default 1.0

filter:        FILTER1,FILTER2

crota:       ROTANGLE              OPTIONAL default 0.0

seeing:    SEEING

—------     one or more of the following

UBVRI:     U,B,V,R,i

ugriz:        u-Sloan,g-Sloan,r-Sloan,i-Sloan,z-Sloan

JHK:         j,H,Kp

nonstd:     Open,Y                    

Example of *.zp file

### 1.82m,AFOSC 2020-04-02   58951.082

U UB 19.929 0.011 0.196 0.018

B BV 22.881 0.010 -0.016 0.009

V BV 23.706 0.011 0.065 0.013

V VR 23.705 0.012 0.103 0.027

R VR 23.492 0.007 -0.019 0.020

I RI 22.622 0.007 -0.107 0.021

u  ug 22.679  0.048  0.078 0.022

g  gr 24.602  0.045  0.057 0.020

r  gr 24.382  0.037  0.089 0.005

r  ri 24.400  0.037  0.089 0.023

i  ri 24.104  0.056  0.061 0.008

z  iz 23.481  0.025 0.160 0.090

Example of .kext file

Sections are identified by keyword site indicated in *.instr


UBVRI: 0.58,0.29,0.16,0.12,0.08

ugriz: 0.59,0.24,0.15,0.11,0.14

Example of SN coordinate file (name as you wish)

Objects to be fitted are selected after checking that they occur in the selected field.

If more then one object are inside the field, they will be fitted sequentially.

sn1 11:18:53.156 +13:05:05.17 11:18:53.2 +13:05:15.17

sn2 11:19:00.156 +13:05:05.17

sn3 20:00:00.123 -50:00:00.20  








ecombine - compute average mjd