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特異新星V838 Mon
の電波観測、その後。
出口修至（国立天文台野辺山）、
松永典之、福士比奈子(東大天文セ)
Kaminski (N. Kopernicus Center, Poland)
V838 Monocerotis？
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Nova（d=-3°）
2002/01 erupted
Light echo
Spectra->M
supergiant
TiO, metal
4 mm SiO. Abs em.
New type of Nova
7.5+0.5Msun merger
何年続くか？
SAAO 1m
Conclusion （２００５）
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1. V838 Mon emits SiO Masers,
approving a cool mass-losing star
2. Vlsr: distance 7 kpc
3. --> Eruptive formation of Msupergiant : living example of stellar
merger
Nobeyama Radio
Observatory
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45-m telescope
6-element 10-m mm-wave
interferometer
Solar Heliograph
(80cm
x84 elements)
22-115 GHz
Beam 40” at 43 GHz
Tsys=200 K (2GHz bandwidth)
SiO Maser? (NRO45m）
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SiO J=1-0 v=1/2 at 43 GHz on 2005/02/23
2005/04/24 again (J=2-1 v=1 negative)
2005/05/23 H2O maser at 22GHz negative
記念写真(2005/02/23)
Further Observations
(Dec. 17, 2005)
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SiO at ~43 GHz
SiO at 86 GHz
CO 115 GHz
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H2O at ~22 GHz
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M-supergiant created?
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爆発前の観測
2MASS blue star >13
K=4-5 mag
IRAS 07015-0346 (F12=0.25 Jy)
No MSX obj.
F10= 10 Jy at present
Projenitor is not M-gaint
7.5+0.5 Main sq. stars.
何年つずくか？
(120” x120”)
Same type, V4332 Sgr
(+ M31 RV)
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Nova in 1994 Feb
Early M0-M5 star
SiO J=1-0 v=1/2
H2O at Nobeyama
both negative
Implication of this discovery
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Vlsr＝54 km/s
Optical Vlsr=42-52 km/s
(P Cyg)
--> Dkin=7 kpc
Munari 2002 ~1kpc
Bond 2003 >6.4 kpc
Munari 2004 8-10 kpc
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Mass losing star
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Nova rate 1 in 10 yr
SiO life ? 2000 yr
Half is 100 objects
～1500 SiO sources
100/1500 ～6.6 %
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10 kpc
1 in every 1 kpc (bright)
V838 Mon conference
2006/05/16-19 at La Palma, Spain
Munari, Goranski, Bond, Henden
Light Echo その後
Distance
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Echo (naive) 0.7 kpc  10 kpc
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[Munari 2002, 2005]
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Kinematic (Vlsr=55 km/s) 7 kpc [Deguchi et
al. 2005]
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Echo Polarization
6.1±0.6 kpc
[Sparks et al. 2008]
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Cluster (luminosity) 6.2±1.2 kpc
[Afsar & Bond 2007]
Keck Spectrum (Kaminski et al. 2008)
B3V
ML?
B3V companion eclipse
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2006 short dip
2008 long
CO mapping (2008)
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Deguchi, 2007
Poland: Kaminski
SiO Maser
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J=1-0 weakening
J=2-1 appearing
(86.243GHZ)
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How long ?
Shell structure ?
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Fast flow (~200 km/s)
Slow flow(~20 km/s)
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SiO not fast flow
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Conclusion
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1. V838 Mon emits SiO Masers,
approving a cool mass-losing star
2. Vlsr: distance 7 kpc
3. --> Eruptive formation of Msupergiant : living example of stellar
merger
How long does it continue ?
Structure of a Merged star
Hayashi phase
(1961) proto-star
 PASJ 13, 450
(roll of convection)
 SPH calc. MS-MS
 Lombardi et al. 2003
(references)
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SiO maser lines in
vibrational states
28
SiO Masers
V=2
Tk=1000-3000 K
r=1--2 x1014 cm
8 micron foundamental
4 micron first overtone
H2O maser T=300--600K.
SiO maser a probe of inner
envelope near photosphere
V=1
6
4
V=0
J=0
1
2
3
5
Historical Light Echo
Ever Observed
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Nova Per 1901 (GK Per)
Discovered on Feb. 21,
1901(first nova in 20c) by
Thomas Anderson, an
Edinburgh Amature
Max 0.2 Mag ->4th in 2w then
oscillate
6 mo. later light echo
With rapid expansion >c
Kapteyn 1902 explained
Light Echo
Where is the dust ?
 van Loon
circumstellar origin
ejected material from
AGB phase
 Tylenda interstellar
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Eruptive Formation of MSupergiants
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Born Again Hypo. 
Post-AGB + MS ? 
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He-shell flash
T. Kato 2004
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(V4334 Sgr Sakurai
obj.)
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Merger Hypo.
MS+dwarf binaries
Tylenda 2004/5
Globular cluster SiO
maser objects
PN/OH/SiO/IR =
V1018 Sco
(Cohen et al. 2005)