(CCD image by Seiichiro Kiyota, by coutesy of Kiyota)
(Spectrum taken by Mitsugu Fujii on Mar. 16.81 UT, by coutesy of Fujii)
HadV46: new variable star (unusual?)
Katsumi Haseda (email@example.com) reports the discovery of a new large amplitude variable star. Although the light variation is not inconsitent with a Mira-type variable, the examination by Haseda of the RealSky image confirms the identificationith
= USNO0750.13650086 183404.041 -144500.23 (2000.0) 14.4 15.5
, which is not red as expected from the light variation. More detailed observation (multicolor photometry and possibly spectrocopy) would be desired to clarify the nature of the object. The object is bright now.
A formatted vsnet-newvar report will appear later. object YYYYMMDD(UT) mag code HadV46 19960525.676 126p Had.VSOLJ (*1) HadV46 19980816.522 <133p Had.VSOLJ HadV46 19981108.403 <133p Had.VSOLJ HadV46 19990219.822 <133p Had.VSOLJ HadV46 19990322.782 <131p Had.VSOLJ HadV46 19990831.483 <130p Had.VSOLJ HadV46 20000206.844 120p Had.VSOLJ HadV46 20000305.810 106p Had.VSOLJ (*1) revised to <130p after later examination of the original photograph Observer's code: Had: K. Haseda (Aichi Japan) 10cm F4.0 twin patrol camera + T-Max400(120)
I note that the odd colors (mb=14.7, mr=14.4 in USNO-A2.0 by the way) could be due to the very crowded nature of the field, which often results in the PMM classifier being unable to handle the scan data.
> I note that the odd colors (mb=14.7, mr=14.4 in USNO-A2.0 by the way) > could be due to the very crowded nature of the field, which often results > in the PMM classifier being unable to handle the scan data.Possible explanation. One might note that a Mira star of this brightness would have been easily recorded in IRAS PSC, but that the IRAS source mentioned looks more closely associated with the redder (on USNO) star. Probably a few immediate multicolor snapshots (or even an unfiltered CCD image) would solve the problem.
Date: Sun, 12 Mar 2000 11:40:09 +0000 From: JGDear Taicho Kato
Subject: HadV46 USNO colour
First I not that this object appears to lie on the edge of a Lynd dark nebula, which is itself amongst a sea of other such nebu which I suppose should have made it appear even redder!
The A type star HIP 90991, a mag 5.7 star, lies quite close and if you can plot the USNO stars in this region as a half degree square of objects coded in 'b-r' by 'colour', and centred on HadV46's position, you'll note a strange vertical 'blue streak' amidst a 'sea of yellow' ascending from this HIP star [a bit generalised]. Although there is nothing to stop all these stars being blue here, at certain resolutions it looks like a drop of liquid that has run! HadV46's position lies just east of this 'blue streak'.
I'm quoting for object USNO0750.13595197 using version 1.3 of Arne Henden's freeware DOS search program on USNO A2.0 data [end figure RA = 4.049s, end figure Dec 00.23"], so I suppose you're quoting A1.0?
Katsumi Haseda (Aichi, Japan) reports the rapid fading of HadV46, the newly discovered possibly unusual variable star by Haseda (vsnet-alert 4381). We have obtained some CCD images this morning, and will inform the result later.
YYYYMMDD(UT) mag observer 19980816.522 <133p (K. Haseda) 19981108.403 <133p (K. Haseda) 19990219.822 <133p (K. Haseda) 19990322.782 <131p (K. Haseda) 19990831.483 <130p (K. Haseda) 20000206.844 120p (K. Haseda) 20000305.810 106p (K. Haseda) 20000313.816 116p (K. Haseda) 20000313.819 116p (K. Haseda)
Message from Hitoshi Yamaoka:
I have done astrometry of HadV46 with Kyoto image taken on Mar. 14.9 UT with GSC-ACT references, then found that the object locates at 18h34m03s.16, -14o45'11".46 (J2000.0), which is not coincident to USNO0750.13650086 (which is suggested to be identified with HadV46 in vsnet-alert 4381). The accuracy is below 1". The nearest USNO star is about 3" apart from this location:
USNO0750.13648719 183402.899 -144511.66 (2000.0) 15.8 18.0
It is possible that this object is nova, new CV, or the other sort of exploding star. Further observation is extremely encouraged.
Hitoshi Yamaoka, Makoto Uemura, Taichi Kato
Further to add:
Unfiltered CCD photometry by the Kyoto team based on Tycho star has confirmed that the object is NOT red. The large amplitude of variability suggests some sort of eruptive or cataclysmic variable (including a nova).
YYYYMMDD(UT) mag observer 19980816.522 <133p (K. Haseda) 19981108.403 <133p (K. Haseda) 19990219.822 <133p (K. Haseda) 19990322.782 <131p (K. Haseda) 19990831.483 <130p (K. Haseda) 20000206.844 120p (K. Haseda) 20000305.810 106p (K. Haseda) 20000313.816 116p (K. Haseda) 20000313.819 116p (K. Haseda) 20000314.855 11.24C (Ouda team)
HadV46 prediscovery observations by Takamizawa object YYYYMMDD(UT) mag code HadV46 19990413.776 <145p Tmz.VSOLJ HadV46 19990414.781 <145p Tmz.VSOLJ HadV46 19990506.615 <135p Tmz.VSOLJ HadV46 19990511.712 <145p Tmz.VSOLJ HadV46 19990609.663 <145p Tmz.VSOLJ HadV46 19990701.500 <140p Tmz.VSOLJ HadV46 19990706.615 <145p Tmz.VSOLJ HadV46 19990731.491 <145p Tmz.VSOLJ HadV46 19990803.520 <145p Tmz.VSOLJ HadV46 19990831.469 <145p Tmz.VSOLJ HadV46 19990909.456 <135p Tmz.VSOLJ HadV46 19990927.415 <140p Tmz.VSOLJ HadV46 19991028.390 <140p Tmz.VSOLJ HadV46 19991029.397 <140p Tmz.VSOLJ HadV46 19991110.376 <140p Tmz.VSOLJ HadV46 19991614.608 <145p Tmz.VSOLJ HadV46 20000209.840 122p Tmz.VSOLJ HadV46 20000211.844 120p Tmz.VSOLJ HadV46 20000216.833 118p Tmz.VSOLJ HadV46 20000302.797 99p Tmz.VSOLJ HadV46 20000308.780 120p Tmz.VSOLJ Tmz: Observer's code: Observer: K.Takamizawa (Saku-machi,Nagano,Japan) Inst.: 10cmR F4 twin patrol cameras T-Max400 120 Comparison stars mag.:GSC&H/T
Sequence of HadV46 (possible nova? Sct)
Selected Tycho-2 and Tycho stars (in case Tycho2 magnitudes are available, prefereably use them).
V B-V 183345.1 -144107 (2000.0) 1016 0.32 TYC5703.1547.1 plx=25.6(29.1) (0.08 0.10) 183345.0 -144107 (2000.0) 1017 0.25 TYC2-5703.1547.1 (10.20 0.05) (10.49 0.05) 183404.6 -144721 (2000.0) 1028 0.50 TYC5703.2593.1 plx=176.3(42.1) (0.08 0.10) 183431.4 -145234 (2000.0) 1104 0.21 TYC5703.1775.1 plx=6.8(60.6) (0.17 0.22) 183431.5 -145234 (2000.0) 1099 0.42 TYC2-5703.1775.1 (11.03 0.11) (11.53 0.10) 183431.3 -144847 (2000.0) 1142 0.85 TYC2-5703.1712.1 (11.51 0.16) (12.50 0.28) 183457.1 -144731 (2000.0) 1032 0.07 TYC5703.2130.1 plx=41.7(22.8) (0.09 0.09) 183457.0 -144731 (2000.0) 1023 0.23 TYC2-5703.2130.1 (10.25 0.05) (10.52 0.04) 183328.3 -143925 (2000.0) 1123 0.75 TYC2-5703.718.1 (11.31 0.15) (12.20 0.23) 183406.3 -145051 (2000.0) 1211E 0.16 TYC2-5703.1731.1 (12.13 0.30) (12.32 0.24)
Charts with Hipparcos/Tycho/Tycho2 magnitudes:
Detailed charts with USNO stars
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