SN 1998bu Ia in M96 (NGC 3368)
OBJECT: SN 1998bu Ia in M96 (NGC 3368) (SABa galaxy) which in Leda is
NGC 3368 (Leda).
DISCOVERY: 1998may09.9 UT by Mirko Villi.
MAXIMUM: 1998may19.8 (JD 2450953.3 +/- 0.5) in B (hernandez2000, p. 229).
But note that jha1999 (p. 82) give JD 2450952.8 +/- 0.8,
suntzeff1999 give JD 2450952.9 +/- 0.5, and
krisciunas2000 give JD JD 2450952.8 +/- 0.8 too.
Until someone does a comparative study, one can only adopt one of these and I'll stick with hernandez2000 for now.
See the US Navy Observatory Julian Date Converter.
This day of the year 139.
SUPERNOVA of the YEAR: M = 73.
HEADER: Header Common header information for this supernovae.
The common header may (or may not) be updated relative to the header information here
(D. J. Jeffery (2006jan01)).
COMMENTS: A core normal (CN) SN Ia.
REFERENCES:
cappellaro2001 Specifically on
SN 1998bu's light echo.
CfA List of Supernovae
where SN 1998bu is noted.
CfA Supernova Archive
This has 35 SN 1998bu spectra from jha1999.
conley2006 General value
of 19.4 days for Ia rise time in B.
hernandez2000 Specifically on SN 1998bu.
jha1999 Specifically on SN 1998bu.
krisciunas2000 Light curves.
paturel2003 (Leda) Leda refererence.
spyromilio2004 SN 1998bu nebular spectra.
suntzeff1999 SN 1998bu light curves.
SUSPECT Index.
SUSPECT Index: SN 1998bu Ia.
There are 33 SN 1998bu spectra and these are from jha1999, cappellaro2001, spyromilio2004, but not hernandez2000.
There is also at least one spectrum that just seems to be Asiago group with no publication: the 1998may29 spectrum.
CORRECTIONS: Heliocentric velocity 891 +/- 3 km/s (2007jun26)
NGC 3368 (Leda).
Galactic foreground reddening 0.11/4=.0275 reddening from
NGC 3368 (Leda).
This dervied from
Schlegel et al. (1998)
OBSERVATIONS: From
1) SUSPECT: out to day100 these are from jha1999, except for one 1998may29 day spectrum
that is just Asiago group.
2) Eddie Baron /home/baron/bru2/spec/sn98bu/meikle: he has some from Peter Meikle
which are probably those hernandez2000, but it's not clear.
3) David Branch /home/branch/synow/98bu: all the hernandez2000 spectra.
SPECTRUM LOG:
JD times for the SN 1998bu spectra of jha1999 and hernandez2000
Bmax from hernandez 1998may19.8 (JD 2450953.3 +/- 0.5).
Somewhat different values are given by others and someone needs
to make a definitive decision.
hernandez2000 generally has better wavelength coverage than jha1999
jha1999 is always 3600--7600, except for 1998may29 where it is 3370.5 to 10290.5.
JD Bmax Heliocentric velocity (Leda, 2007jul01)
0953.3 891.
Heliocentric velocity Z redshift
891.0000000000 0.0029720561
Index JD of some kind Observer phase Rest phase
1 946.4000000000 -6.9000000000 -6.8795535809 ! hernandez2000 1998may12.90 3595.67871--9097.00000
2 949.3800000000 -3.9200000000 -3.9083840633 ! hernandez2000 1998may15.88 3304.34888--9067.55078
3 951.4000000000 -1.9000000000 -1.8943698266 ! hernandez2000 1998may17.90 3304.84253--9076.6582
4 952.4000000000 -0.9000000000 -0.8973330758 ! hernandez2000 1998may18.90 3249.29028--9460.
5 961.6799500000 8.3799500000 8.3551181203 ! jha1999 1998may28.18 3615.0036621094--7612.21540892113
6 962.5625000000 9.2625000000 9.2350529048 ! Asiago 1998may29.0625 3370.5124511719--10290.562491417
7 964.7200000000 11.4200000000 11.3861596948 ! hernandez2000 1998may31.22 --
8 966.6800000000 13.3800000000 13.3403517264 ! hernandez2000 1998jun02.18 4915.23486--10265.2998
9 972.4000000000 19.1000000000 19.0434019413 ! hernandez2000 1998jun07.90 3601.3999--9292.60645
&specnamelist
aname='sn1998bu Ia 1998_05_'
ebv=.0275 !
epoch= ! This parameter needs to updated for the particular spectrum.
idifmake=0
iformat=1
ismooth=0
itick=2
itickln=4
t_rise=19.4d0 ! \citep{conley2006}, Just an average rise time.
v_helio=891.
ymin2=1.d-14
ymax2=12.d-14
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 and someone:
SPECTRUM LOG for the hernandez2000 spectra
Date Time(UT) Epoch(d) Tel. Instr. Wavel. Rg. Resolution Grating Observer
-----------------------------------------------------------------------------------------
12 05 98 21:31 -6.8 WHT ISIS 3590-9097 5.8A (2pix) R158B,R J. Iglesias
15 05 98 21:05 -3.8 INT IDS 3300-9072 13A (2pix) R150V P. Sorensen
17 05 98 21:34 -1.8 INT IDS 3300-9081 13A (2pix) R150V D. de Winter
L. Miranda
18 05 98 21:34 -0.8 INT IDS 3207-9460 6.6A (2pix) R300V D. Pollacco
31 05 98 05:14 +11.5 WIYN Hydra 3541-5573 4.0A (4pix) 632(I) ?. Smith
02 06 98 04:16 +13.5 WIYN Hydra 4910-10265 5.2A (2pix) 316 D. Willmarth
07 06 98 21:26 +19.2 INT IDS 3602-9298 6.6A (2pix) R300V D. Pollacco
ISIS resolution from manual, and header showing TEK chip in use.
INT resolution from manual, and header showing TEK1024 chip in use.
WIYN resolution based on FWHM of cleanest arc lines.
Time(UT) is the START time for the integration on SN 1998bu.
Epoch is based on tBmax = May 19.7
Information from hernandez2000 from 000READ.ME file.
6/7/99
This directory contains our final fluxed optical spectra for
SN 1998bu at early times. They were reduced in the usual way
and then scaled by various factors to match the JKT photometry
using the JKT filter functions, TEK4 response function (TEK4
was used for the JKT data) and the La Palma transmission function.
The spectra and the scaling factors *which have now been applied*
to these spectra are:
12may.sdf x1.41
15may.sdf x0.94
17may.sdf x2.23
18may.sdf x1.77
31may.sdf x1.05
02jun.sdf x0.83
07jun.sdf x1.62
The 15may.sdf spectrum had already been scaled to match a broad
slit spectrum. Thus, the required scaling factor is smaller
than typical. For further details, see my notebook pages 221-2.
(From some member of Hernandez et al. I guess. This header
applies to spectra from David Branch's /synow/098bu directory.
David thinks that these have been deredshifted it seems. Is
he right? I think not.
Frankly, some of the hernandez2000 spectra look a bit distorted in orginal format
and seem to fall off to the red. Did we get the final calibration?)
