Reporting SN Measures


Members of the CCD-Web group send their measures to the newsgroup.

Other send their measures to SNWeb2

In any case, the hereafter described format must be used.

The measures and images are then collected, and published on the SNWeb2 site.

The message must be sent in 'Plain Text' mode and never in 'HTML' mode.

Subject of the message

To allow an easy and automated collection, the subject of the mail must start with '[SN][MEAS]', followed by the name of the measured SNs:


Subject Comments
[SN][MEAS] 2002B SN Name upper Case if one Character
[SN][MEAS] 2002ap SN Name lower Case if two Characters
[SN][MEAS] 2002B;2002ap Separator is ";" if more than one SN

Table 1. Message Object Examples
Use square Bracket and upper Case for [SN][MEAS].


Body of the message

The body contains at least the measures and may contains additional technical comments about the measures.

Non technical comments must be avoided and published in a separate mail.

There is one measure per line, and one line per measure, with the following description:

The format is explained hereafter with examples:

SN Comments
SN2002B Number Upper Case if one Character
SN2000ap Number Lower Case if two Characters

Table 2. SN Name (Examples)
'SN' is always upper Case.
No Space between SN and 2002 !

Date Comments
20020315.123 yyyymmdd.ddd, NO interspersed Space

Table 3. Date Format (Middle Time of Exposure)
'yyyy'=year, 'mm'=month, 'dd'=day,
'.ddd' = fract of Day rounded to 3 or 4 decimal places,

S/N Magnitude Comments
>50 14.63 Only for high S/N ratio
10..50 146 No decimal Point needed, but accepted if present
<10 146: Uncertain Measure

Table 4. Magnitude Format versus S/N ratio
How to report a 14.63 Measure.

Filter Comparaison Star Magnitude Reference VSNET Band
None "R" USNO CR
None "V" C
R "R" Calibrated Sequence Rc
B "B" Calibrated Sequence B
V "V" Calibrated Sequence V
I "I" Calibrated Sequence Ic

Table 5. VSNet Band
Filters in KRON-COUSINS System
The use of Filters presumes a suitable reduction has been performed.

Observer Comments
RPo Observer has a 3 Characters VSNET Code
R. Poncy New Observer

Table 6. Observer
Pay Attention to the Case, 'ABc' is not 'AbC'
Don't confuse VSNET Code for IAU Observatory Code.

On the same line, items are separated with a 'Space' character ('Tab' is also allowed) but there is no space between the magnitude and the spectral band:

SN2002an 20020310.809 164CR LLA
SN2002ap 20020310.789 138CR LLA
SN2002bo 20020310.832 156CR LLA

Table 7. Examples
3 Measures by J. M. LLAPASSET)


Other information

On a general basis, the number of reported digits after decimal point must meet the measure accuracy. 
(see table 9):

Item Comment Measure Report
Elevation Rounded to nearest degree 60.2345 60
Airmass Two or three digits after decimal point 1.56789 1.57
S/N Integer Value 12.83 12
FWHM One digit after decimal point + 'pixel' or 'arcsec' 2.345 2.3 arcsec
Uncertainty Add 0.05 magnitude, no more than 2 digits +/-0.031 0.08
Flux Dependant on scaling and gain 123456.789 Don't report

Table 8. How to report

Only items from Table 9 are allowed and are put on the same line, with a space as separator. The line must follow immediately the measure.

Item Description Codes Example
Used sequence AH = Arne Henden
AA = AAVSO Chart
AH = Arne Henden
BS = Brian Skiff (LONEOS)
MB = MultiBand (general)
SW = SNWeb calibration
TY = Tycho (Vt is not the V standard !)
Star used as calibration.
If more than one star (not recommended), they are separated by a slash ('/'), without any space.
For USNO-A2, if the designation is ambiguous, append an hyphen and the B magnitude
For USNO stars, R magnitude is used.
For calibrated stars, centimagnitude is used
and the band specified
Method Photometry method A = Aperture
G = Gaussian Fit
FWHM Means FWHM in arcsec One digit after decimal point,
no space, 0.0" if unknown
Exposure Total exposure in seconds,
always at least 3 digits left padded by ZERO as needed, no space

Table 9. Complementary Data
Ex: 'US 127/152/155 A 2.3" 090s'
Respect the Order and the Separator (ONE SPACE)!

Sending Images


As much as possible, image size must be 5 * 5 or 8 * 8 arcminutes.

No text must be put on the image. The SN may be shown using

and the reference star with a red colored circle or square.

The JPG formatted image is uploaded on the SNWeb2 FTP server in an observer reserved directory, using the protocol provided by Jean-Claude PELLE.


Image names are formatted as follows and explained in Table 10:


Upper and lower cases are relevant. Image name is written on the line immediately following the related measure (see example table 14).

Code Description Example
YY Discovery year modulo 100 ("02" pour 2002) 01
AA Letters of SN name, always 2 characters, append and underscore 
if the name contains only one upper case letter
B_, ay
US User ID, assigned to each observer (two uppercase letters)
This is not the VSNET code.
F Band/Filter ('C' for clear, B, V, R, I) C
yyyy Year Observation 2001
mm Month Observation 06
dd Day Observation 19
hh Hour Observation (UT) 22
mm Minute Observation (UT) 35

Table 10. Image name (pay attention to upper/lower case)
An unfiltered Image exposed on 19. June 2001 at 22:35 UT
by Pierre ANTONINI (User Code = PA) is named
- for SN 2001B '01B_PA_C200106192235.jpg'
- for SN 2001ay '01ayPA_C200106192235.jpg'

Comments  by Observer

After the measure and the image name, the observer is allowed to add some comments.

The first comment line must start with the sign '#' and no blank lines are allowed between the measure and the comment.

If the comment use more than one line, it ends with

    - the first blank line
    - another measure
    - the end of the mail

(some measure).... 
#This is a comment.

#This is ignored (blank line inserted).

(some measure)...
#This is a comment.
This is the second paragraph.

(some measure)...
#this is a suitable
3 lines

(some measure)...
#this is also a
#3 lines comment
#with '#' inserted in front of each line.

(some measure)...
This is ignored (no '#')

(some measure)...

#This is ignored (blank line after measure)

Table 11. Some good and bad Comments Examples
See also Table 14.

Special Configuration

To help observers and avoid useless repetitions, the user configuration (telescope + CCD) is stored, and automatically added when the measures are published on the site.

If an observer occasionally uses another instrument, then he/she adds comments lines as shown in tables 12 and 13:

0.16-m f/3.3 reflector  
0.20-m f/3.2 reflector  
0.20-m f/5.5 reflector  
0.20-m f/6.7 reflector  
0.20-m f/10.0 reflector 
0.23-m f/3.4 reflector  
0.23-m f/4.1 reflector  
0.25-m f/2.7 reflector  
0.28-m f/3.5 reflector  
0.28-m f/6.8 reflector  
0.30-m f/6.4 reflector  
0.36-m f/6.0 reflector  
0.41-m f/4.5 reflector  
0.62-m f/10.0 reflector 

Table 12. Some Examples for Telescope Description
The Comment must appears as (See Table 14):
#TEL 0.41-m f/4.5 reflector


Table 13. Some Examples for CCD Description
The Comment must appears as (See Table 14):
#CCD KAF-1602E


[SN][MEAS] 2001ay
SN2001ay 20010619.941 163CR Ant
OT  123/152/155 A 2.9" 300s
#some high clouds

SN2001B 20010621.896 14.15CR Ant
US 147 A 2.7" 090s
#TEL 0.41-m f/4.5 reflector
#CCD KAF-1602E

Table 14. Measures with Image
USNO Stars 123R, 152R and 155R from Odd Trondall Image were used.
Measure was done with Aperture Photometry.
FWHM is 2.9 arcsec and total Exposure 300 seconds .
Comment indicates some clouds were present.


A new observer send the following data to Jean-Claude PELLE,

The three last data will allow to propose tools to assist the observer.

In return, the observer receives, a two uppercase observer code (See 'US' above in image name), and a password to access the FTP site.

Last Update 02 April 2002
[SN Home Page]
Software SNWeb provided by Jean-Claude PELLE