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sending error

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sending error

Hi everyone, I need help, I have problems sending spectra, every time I get this error "star not in database" I also do all the possible name changes but useless, I contacted the service center and I was helped to insert the work, it seems that my Isis software and Demeter generate a double JD key, honestly I can't disturb the service center every time, could you help me?
Massimo Di Lazzaro

Reliable Fits Editor?

Hello Massimo,

While we at HQ are always welcome to help what would be useful for the community at large is a way to edit fits headers. Is there a reliable program for this? I know you can do it through various programming languages, but if anyone knows of one with a gui interface, it would be very helpful.

Bert Pablo
Staff Astronomer, AAVSO

FITS Header Editor


F4W2HDU is a free FITS header edotor that I've found useful & easy to use.  It can be downloaded from .  It's intended for bulk changes of multiple file headers, but works fine for a single file.

Wayne Bailey

FITS header editor


I just checked that BASS also can edit the FITS header on both image & profile files.  It also allows you to add new keywords (which can be dangerous if you don't format them correctly),  Also, unlike ISIS, it doesn't discard unrecognized keywords from the existing header.

Wayne Bailey

Robin Leadbeater
what exactly is the problem

Hi Massimo, Bert,

The header can be edited in ISIS provided the keyword is already there. (See attached screenshot.) There should not be any need to edit the header produced using ISIS specifically for the AAVSO database however. Can you describe what exactly  the problem is ?




If I remember correctly, Massimo's main problem was that the JD-MID keyword ended up being 0 even though he had a reasonable value for the date observed. If JD-MID isn't listed, then we will just calculate it, but if it's listed then we assume the listed value is correct. However, 0 isn't a valid time for JD-MID and so it fails. 

Robin Leadbeater
bad exptime ?

Curious. I have not heard of  this problem before with ISIS. (JD-MID has been in the ISIS header since 2012). Can you recall what the value for EXPTIME was?  I am wondering if ISIS perhaps failed to calculate the exptime correctly due to invalid or corrupted values from a set of sub exposures which might then knock on to the JD-MID time. If not it could be raised as a potential bug on the ARAS forum.


Header Values

Hello Robin,

I don't know how it was calculated, but I can show you the header values of the file:

<bound method Header.keys of SIMPLE = T / File does conform to FITS standard
BITPIX = -32 / Number of bits per data pixel
NAXIS = 1 / Number of data axes
NAXIS1 = 4335 / Length of data axis 1
CRVAL1 = 3700.08666992188 / Coordinate at reference pixel
CDELT1 = 0.876572669 / Coordinate increment
VERSION = 'ISIS V5.9.7' / Software version
OBJNAME = 'Y Cassiopea' / Current name of the object
DATE-OBS= '2020-04-24T20:37:04.3' / Date of observation start
EXPTIME = 150 / [s] Total time of exposure
EXPTIME2= ' ' / Exposure decomposition
BSS_INST= 'Spectra1' / Instrument
BSS_SITE= 'Max1Obs ' / Observation site
CUNIT1 = 'Angstrom' / Wavelength unit
CTYPE1 = 'Wavelength' / Axis type
Q_CAL = '0 ' / Quality flag 4-excellent
CRPIX1 = 1 / Reference pixel
BSS_VHEL= 0 / [km/s] Heliocentric speed
SPE_RPOW= 0 / Spectral resolution power
JD-OBS = 0 / JD start observation
JD-MID = 0 / JD mid observation
JD-HEL = 0 / JD heliocentric mid-obs
GEO_LONG= 0 / Obs. geographic longitude
GEO_LAT = 0 / Obs. geographic latitude
GEO_ELEV= 0 / Obs. geographic elevation >

The main issue is that JD-MID at the bottom is 0. (Not the error the system is complaining about is the greek letter gamma in the name, but that is easily corrected for. Even when you do the JD-MID is the real problem).

Robin Leadbeater
no JD-OBS either

I see  JD-OBS is set to zero too, not just JD-MID.  This is very odd as ISIS should have generated that directly from DATE-OBS which it picks up from the original spectrum image. It looks like there has been a problem somewhere in the reduction using ISIS.  It is unlikely to be a bug but I am not sure what has gone wrong. 

Robin Leadbeater
fits header editing

There is also this recent thread on the subject which turned up some suggestions though I have not tried them



nkrumm's picture
FITS header editing program

   I wrote a small (and hopefully intuitive) Windows program last summer to edit FITS headers, and I've been using it successfully for almost a year. I can't upload it here, but if anyone would like a copy, just email me at I'm happy to share either the *.exe file or the C# source code. The program includes a help file with instructions on how to use it. It works for both 2-D images and 1-D spectral profiles.

Thanks for the info I attach

Thanks for the info I attach the header of the fit generated by Isis

But the strange thing is that

But the strange thing is that I have the same problem even if I process the spectrum with Demetra, since I have the Alpy600 I also tried with this software, I don't really know what to do

Robin Leadbeater
That looks ok

That header looks ok to me. Both JD-OBS and JD-MID are there as expected. 


Robin Leadbeater
All the other values that

All the other values that were 0 in the header that Bert posted are now filled too so it looks like ISIS ran correctly for that spectrum. Was this spectrum also rejected by the AAVSO database ?

Thanks Robin for the help,

Thanks Robin for the help, and thanks to all of you, yes, when I entered it again it didn't go well it was rejected: "star not in the database"

Robin Leadbeater
object name

I think the object name has to be recognised in VSX.  Sheliak was not recognised but it is under the name Bet Lyr or  HD 174638 


Robin Leadbeater
recognising object names

I am not sure what source VSX uses as a cross reference for names but the BeSS database and ELODIE archive for example uses SIMBAD to cross check and so recognises Sheliak and even obscure names like Renson 48890 as Beta Lyrae  

Thanks Robin, so to avoid

Thanks Robin, so to avoid errors on names I should check on Simbad

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