SN 1981B Ia in NGC 4536 in the Virgo Cluster
OBJECT: SN 1981B Ia in NGC 4536 in the Virgo Cluster (SABb) which in
Leda is
NGC 4536 (Leda).
DISCOVERY: 1981mar02 UT by Tsvetskov (1981).
MAXIMUM: Bmax 1981mar07.21 UT (JD 2444670.71 +/- 0.88) (riess2005).
1981mar08.5 UT (JD 2444672.0 +/- 0.2) in B (krisciunas2000).
JD 2444672 (buta1983) which is the same as krisciunas2000 to less precision.
As krisciunas2000 include Adam Riess, I have to believe that riess2005 is now the
preferred value and must update the phases accordingly.
See the US Navy Observatory
Julian Date Converter.
Sometimes USNO is unavailable: try
OnlineConversion.com: Julian Converter
which is a modified version of USNO.
This day 67 of the year.
SUPERNOVA of the YEAR: M = 2.
Those were the good old days when there were only 10 to 20 SNe per year and we never
ran out of the alphabet.
HEADER: Header Common header information for this supernovae.
The common header may (or may not) be updated relative to the header information above
(D. J. Jeffery (2007jan01)).
COMMENTS: This is a broad line (BL) SN Ia as David now calls it. Once it was the fairest coriest normalist
of them all, but now David says not so normal with casual disrespect.
REFERENCES:
branch1983
David's paper on 81B spectra. All the 81B spectra we know of are reported there.
buta1983
Early photometry of 81B.
CfA List of Supernovae
where SN 1981B is noted.
CfA Supernova Archive
For SN 1981B, this has 0 spectra and 0 photometry.
conley2006 General value
of 19.4 days for Ia rise time in B.
krisciunas2000 They
give a new B maximum which is probably much better established than that of buta1983, but
has in fact the same numerical value.
paturel2003 (Leda) Leda refererence.
riess2005 Gives an updated Bmax.
SUSPECT Index.
SUSPECT Index: SN 1981B Ia
There are 0 spectra.
There is a great picture of
Fritz Zwicky (Wikipedia).
Just say Fritz Zwicky aloud and you can tell he's an up-to-date person.
CORRECTIONS: Heliocentric velocity 1807 +/- 2 km/s (2007jul03) from
NGC 4536 (Leda).
Galactic foreground 0.08/4=.02 reddening from
NGC 4536 (Leda).
This is derived from
Schlegel et al. (1998).
OBSERVATIONS: From (1).
1) David Jeffery's old catalog that originally must have come from David Branch
and may have passed back to him at some time I think.
These spectra have been transformed so many times, it is hard to know what problems
exist in them now.
Maybe the originals exist on some aging, unreadable magnetic tape at the McDonald
observatory in Texas.
All the ones up to day 1981jul01 were reported in branch1983, of course.
The later nebular are almost unprovenanced. I got some from David Branch and
others (which may be duplicates) from Robert Harkness and no one remembers who
took them or anything else about them.
2) David Branch's cache is in /home/branch/synow/81B, but those are the same as far as
I've checked.
3) Eddie Baron has no 81B spectra.
SPECTRUM LOG:
JD times for the SN 1981b spectra of branch1983.
branch1983 only gave whole number values, but by comparing UT dates
and knowing the observations were done in Texas and so
at the .25 +/- .25 of the UT day, we know that the JD's have to end
in .75 +/- .25.
I can't imagine that the man down the hall has any better information
although the folks at the McDonald Observatory in Texas may have some archived times.
Bmax 1981mar07.21 UT (JD 2444670.71 +/- 0.88) (riess2005). Now prefered.
Bmax JD 2444672.0 +/- 0.2 (krisciunas2000).
From the 7600 A telluric line, I know a few of the spectra are
in the rest frame, and I suppose they all are.
Nope. The 1981mar27 spectrum is observer-frame.
JD Bmax Heliocentric velocity (Leda, 2007jul01)
4670.71 1807.
Heliocentric velocity Z redshift
1807.0000000000 0.0060275032
Index JD of some kind Observer phase Rest phase
1 4671.2500000000 0.5400000000 0.5367646494 ! branch1983 1981mar07.75 3081.60--8390.37 (rest from telluric)
2 0.0000000000****************************** ! 4-day averaged spectrum.
3 4676.7500000000 6.0400000000 6.0038120039 ! branch1983 1981mar13.25 5623.00--7134.06 (rest?)
4 4687.7500000000 17.0400000000 16.9379067131 ! branch1983 1981mar24.25 3656.27--8658.24 (rest from telluric)
5 4690.7500000000 20.0400000000 19.9199325428 ! branch1983 1981mar27.25 3509.66--8703.33 (observed from telluric)
6 4694.7500000000 24.0400000000 23.8959669825 ! branch1983 1981mar31.25 3398.46--8756.76 (rest from telluric)
7 4698.7500000000 28.0400000000 27.8720014222 ! branch1983 1981apr04.25 missing spectrum unless the apr05 spectrum
8 0.0000000000****************************** ! is really a an apr04-apr05 average.
9 4699.7500000000 29.0400000000 28.8660100322 ! branch1983 1981apr05.25 3705.07--6398.59 (rest?)
10 4705.7500000000 35.0400000000 34.8300616917 ! branch1983 1981apr11.25 3842.52--6300.77 (rest?)
11 4719.7500000000 49.0400000000 48.7461822306 ! branch1983 1981apr25.25 4344.48--7068.86 (rest?)
12 4728.7500000000 58.0400000000 57.6922597199 ! branch1983 1981may04.25 3299.13--5387.26 (rest?)
13 4734.7500000000 64.0400000000 63.6563113794 ! branch1983 1981may10.25 5655.51--7162.68 (rest?)
14 4765.7500000000 95.0400000000 94.4705782870 ! branch1983 1981jun10.25 3369.02--6206.58 (rest?)
15 4786.7500000000 116.0400000000 115.3447590954 ! branch1983 1981jul01.25 4184.47--7165.75 (rest?)
16 4940.7500000000 270.0400000000 268.4220850235 ! mcdonald1981 1981dec02.25 2660.90--5641.74 (?) (harkness)
17 4941.2500000000 270.5400000000 268.9190893285 ! mcdonald1981 1981dec02.75 2660.90--7194.90 (?) (harkness)
18 0.0000000000****************************** ! May be an average of dec02 and dec03.
19 4941.7500000000 271.0400000000 269.4160936334 ! mcdonald1981 1981dec03.25 4192.31--7194.90 (?) (harkness)
20 4996.7500000000 326.0400000000 324.0865671792 ! mcdonald1981 1982jan27.25 3120.16--5665.77 (?) (harkness)
21 5027.7500000000 357.0400000000 354.9008340868 ! mcdonald1982 1982feb27.25 4196.02--7182.89 (?) (harkness)
22 5028.7500000000 358.0400000000 355.8948426967 ! mcdonald1982 1982feb28.25 3262.64--5926.60 (?) (harkness)
&specnamelist
aname='sn1981B Ia 1981_03_'
ebv=.02 !
epoch= ! This parameter needs to updated for the particular spectrum.
idifmake=0
iformat=-1 ! All the branch1983 spectra have been deredshifted, but one has to check.
ismooth=0
itick=2
itickln=4
t_rise=19.4d0 ! conley2006: just an average rise time.
v_helio=1807.
ymin2=.1d-6
ymax2=3.d-5
ymin3=.3
ymax3=3.
wlammin1=
wlammax1=
wlammin2=
wlammax2=
wlammin3=
wlammax3=
/
Postscript plot of the spectrum.
Postscript plot of the spectrum with local normalization.
Information from somewhere:
