V838 Mon = Peculiar Nova in Monoceros

V838 Mon (V838 Monocerotis) = Peculiar Nova in Monoceros (Nova Mon 2002) = GSC 4822.39

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(Extremely brightened V838 Mon!! Ondrej Pejcha et al., Brno)

(Incredible outburst on 2002 Feb. 2!)

(Spectrum by M. Fujii, during the rising stage of the great eruption)

(H-alpha spectrum by K. Ayani, Bisei Astronomical Observatory, during the rising stage of the great eruption)

(CCD image by Akira Takao just after the discovery)

Ic
(CCD image taken by S. Kiyota; the bright star near the center of the lower image (Ic-band) is the object). U

(UBVRI images, taken by M. Uemura, Ouda Station)

Takashi Iijima (Asiago) relays the discovery report of a possible nova by N. J. Brown (details unknown).

The existence of the object has been confirmed by Iijima, Seiichiro Kiyota (Tsukuba, Japan), Akira Takao (Kitakushu, Japan), Makoto Uemura (Ouda Station, Kyoto University).

H. Yamaoka, Kyushu University, measured a precise position of this object using the V-band CCD image (with 0.25-m SCT) taken on Jan. 9.496 UT by S. Kiyota, Tsukuba, Ibaraki, Japan, as: R. A. = 7h04m04s.801, Decl. = -03o50'50".77 (equinox 2000.0, 29 Tycho-2 stars, uncertainty about 0".3). It suggests that this object is identical to IRAS 07015-0346, or 2MASS source whose position end figures are 4s.82, 50".5.

According to Iijima's report, the spectrum is dominated by a very red continuum, but without Balmer feature (neither in emission nor absorption). Several weak metal lines are seen in emission. Neither H-alpha emission nor prominent TiO absorption bands are seen on a low-resolution spectrum taken by Kiyota.

The corresponding 2MASS object is:

07:04:04.82 -03:50:50.5 J=13.905 H=13.480 K=13.347

The IR color (and also V-J color) excludes the possibility of a long-period variable. The IRAS color (of the liklely far IR counterpart) is very unusual for a stellar object:

070405.0 -035046 (2000.0) IRAS07015-0346 0.250L 0.250L 1.398 4.582 -1%

Although the object seems to be some sort of an eruptive object or a peculiar nova, the nature of the object is still unknown. It may be possible the phenomenon is related to a flash in hydrogen-poor environment.

H. Maehara (Saitama, Japan) reports the following visual observation:

object         YYYYMMDD(UT)   mag  code
GSC4822.39     20020109.625   107  Mhh.VSOLJ

(GSC name tentatively given here)

Follow-up observations of this peculiar object is strongly needed.

Regards,
Taichi Kato
VSNET

Iijima-san also reported the presence of a very weak H-alpha emission (having a P Cyg profile). The velocity of the absorption component is reported to be about -200 km/s. More details will be reported in IAUC.

Sepctrum by M. Fujii

Finding chart

Chart by Reinder Bouma/Edwin van Dijk

Link to the chart

AAVSO chart

Link to the chart

T. Scarmato's color image

Link to the image

Maurice Gavin's page

Link to the page

Chart by Japan Variable Stars Study Association

Link to the chart

Giant outburst!!

Subject: [snet-campaign-v838mon 3] V838 Mon recent reports

From: "Lubos Brat" 
Date: Sat, 2 Feb 2002 20:29:02 +0100
Subject: [vsnet-alert 7131] V838 Mon BRIGHT!!!

According to my tonight visual estimate and reports from my collegues using
CCD cameras, the V 838 Mon = Possible Nova Mon 2002 is EXTREMLY BRIGHT:

     20020202.805      8.80   (Lubos Brat)

Regards
Lubos Brat, Czech republic
MEDUZA Group

Date: Sat, 2 Feb 2002 20:54:17 +0100 (CET)
From: Petr Sobotka 
Subject: [vsnet-alert 7133] Re: V838 Mon BRIGHT!!!

We have made some frames of V838 Mon in the I band early in the night, but
the star is too bright. We switched 40cm Brno telescope to this target and
are doing 20s exposures in the V band. The star is much brighter than 106
comparison on the AAVSO chart. We will write detailed report later.

Best regards,

Ondrej Pejcha and Petr Sobotka
MEDUZA group

Date: Sat, 2 Feb 2002 21:19:08 +0100 (CET)
From: Petr Sobotka 
Subject: [vsnet-alert 7132] Re: V838 Mon BRIGHT!!!

We confirm Lubos Brat's observation. V838 Mon is really bright!!! 

20020202.842   8.73   Petr Sobotka
20020202.843   8.63   Ondrej Pejcha

Is there another one who confirms this?

Petr Sobotka and Ondrej Pejcha
MEDUZA

From: "Maciej Reszelski" 
Date: 	Sat, 2 Feb 2002 21:37:39 +0100
Subject: [vsnet-alert 7134] Re: V838 Mon BRIGHT!!!

Just back from observing after read Lubos massage.
I confirmed outburst. here is very preliminary observation:

MONV838   20020202.9    89    RMQ.AAVSO

Star was at 11mag last night!

Detal raport tomorrow.

Best regards,
Maciej

Date: Sat, 2 Feb 2002 21:42:38 +0100 (CET)
From: Petr Sobotka 
Subject: [vsnet-alert 7135] Re: V838 Mon BRIGHT!!!

Dear all,

from average of 5 V band frames we have obtained following magnitude of
V838 Mon:

20020202.836    8.06 +/- 0.01 mag CCD + V filter

We have used AAVSO comparison star with magnitude 106 for reference.

Best regards,

Ondrej Pejcha and Petr Sobotka
with 40cm Brno telescope
MEDUZA

Date: Sat, 02 Feb 2002 21:47:52 +0100
From: Andreas Krawietz 
Subject: [vsnet-alert 7136] Re: V838 Mon BRIGHT!!!

I watching V838 visually, Cass 200/3000, f=40.
20020202.917   8.60
Ref.st. GSC 4822 3258/2977 (mag 91/85), AAVSO Chart 011002

Andreas Krawietz
Tharandt, Saxony

From: "eddy muyllaert" 
Date: 	Sat, 2 Feb 2002 22:01:21 +0100
Subject: [vsnet-alert 7137] Confirmation V838 Mon brightening!!!

Star             UT            Mag
-------------------------------------
MONV838     Feb 2.851     8.8     Seq. AAVSO

Eddy Muyllaert
Oostende, Belgium
eddy.muyllaert@ping.be

Date: Sat, 2 Feb 2002 22:48:09 +0100 (CET)
From: Petr Sobotka 
Subject: [vsnet-alert 7138] V838 Mon rapidly brightening!

Dear all,

we have preliminary reduced last 3.6 hours of our CCD V band observations
of V838 Mon. The star is brightening linearly with incredible rate of 2.37
mag/day (~0.1 mag/hour)! We will continue observing further...

Best regards,

Ondrej Pejcha and Petr Sobotka
40cm telescope, SBIG ST7
Brno, Czech Republic
MEDUZA group

Date: Sat, 2 Feb 2002 23:00:34 +0100
From: "Jose Ripero" 
Subject: [vsnet-alert 7139] Outburst of V  838 Mon

Dear observers :

        Just a few minutes I had seen the outburst of V 838 Monoceros.
The observation is :

            20020202.8958        Mg. 8.5  AAAVSO chart d.  33.5 cms.
f/4.5  x 125.  Comparison star 74 and 91

        I had checked several times the star's field and clearly the
star is in outburst.

        Sincerely,

        jripero@wanadoo.es
        M 1 Group / Madrid - Spain

From: Pavol A. Dubovsky 
Date: Sat, 2 Feb 2002 23:04:50 +0100
Subject: [vsnet-alert 7140] V838 Mon

Another confirmation of V838 Mon rapid brightening

MONV838    20020202.875  81 DPV
MONV838    20020202.903  81 DPV

Clear skies!
Pavol A. Dubovsk& Chermelin 300/1504 mm
Podbiel, SLOVAKIA
member of the MEDUZA (http://www.meduza.info) group
e-mail: vkco@isternet.sk
http://www.vkco.sk

Date: Sun, 03 Feb 2002 01:12:17 +0100
From: Lukas Kral 
Subject: [vsnet-alert 7141] V838 Mon still rising!

Dear colleagues,

I just looked at this star by 25x100 binocular:
MONV838  20020202.969  81  L. Kral

I used 5 comparisons (mags from Tycho, recomputed to V).

I also started a CCD run on this star (at 22h UT), and 
after 2 hours the preliminary light curve shows linear
rising trend at approx. 0.06 mag/hour!

A small photo-lens (with SBIG ST-7 and R filter of
RGB set) is used, so the high brightness of this star is
no problem for me.

I will send the resulting data to vsnet-campaign-data.

Best regards,
Lukas Kral

********************************************
Project Eridanus
http://ostrava.astronomy.cz/
Observatory and Planetarium of Johann Palisa
Ostrava, Czech Republic
********************************************

From: "Lubos Brat" 
Date: Sun, 3 Feb 2002 01:48:46 +0100
Subject: [vsnet-alert 7142] V838 Mon

Another visual estimate of famous V838 Mon:

20020202.889  85    (Lubos Brat, Pec pod Snezkou, Czech republic)

I've drawed a light curve and posted it at MEDUZA web-site =
www.meduza.info.
Exact URL: 
http://www.meduza.info/v838mon_bright_vsnet.gif

Regards
Lubos Brat
- MEDUZA Group

Date: Sun, 3 Feb 2002 03:36:02 +0100 (CET)
From: Petr Sobotka 
Subject: [vsnet-alert 7143] Re: V838 Mon rapidly brightening!

Dear all,

we have just finished our run on V838 Mon in the V band using 40cm
Newtonian telescope of N. Copernicus Observatory in Brno, Czech
Republic. We have obtained over 600 frames between 2002 Feb. 02.740 and
2002 Feb. 03.060 (UT). The star has brightened of about 0.56 mag
linearly. Using 10.6 comparison from the AAVSO chart (Henden
photometry) we estimate preliminary range 8.23 - 7.67 mag.

Best regards,

Ondrej Pejcha and Petr Sobotka
MEDUZA

Discovery story by MEDUZA observers

Subject: [vsnet-campaign-v838mon 61] V838 Mon outburst - discovery story by MEDUZA observers

V838 Mon outburst - discovery story by MEDUZA observers

Almost all nights in January 2002 were cloudy. However, during the last week of January the temperature has unusually increased. From Jan. 28 to Feb. 3 the historical temperature records (1884) were overcome in the Czech Republic. It had a secondary effect: on Feb. 2 (Saturday) many observers wanted to observe variable stars - finally!

The first MEDUZA observer who discovered unusual brightness of V838 Mon was Ladislav Smelcer from Valasske Mezirici Observatory. He has been observing mostly long period variable stars (especially Miras) since the end of 1998. On Feb. 2, 18h 47min UT he had done CCD V filtered observation of V838 Mon showing it at magnitude 8.17. It was so surprising that he immediately called another observer to confirm this.

L. Smelcer contacted one of the best MEDUZA observers Lubos Brat from Pec pod Snezkou. On Feb. 2, L. Brat had been observing variable stars and had planned to observe stars from Monoceros when L. Smelcer suddenly called him. Brat's visual estimate on 19:19 UT confirmed the unexpected outburst - V838 Mon was at magnitude 8.80 mag (note: diferrence between CCD+V and visual observations is due to the large B-V index of variable star). L. Brat immediately called Ondrej Pejcha and Petr Sobotka, who had been observing variables at N. Copernicus Observatory and planetarium in Brno. After that, L. Brat ran to his house (ski tourist center Alena) and sent alerts to VSNET and MEDUZA discussion mailing list.

Feb 2. was the first CCD night in life of O.Pejcha. P.Sobotka was training him how to manipulate with telescope and CCD camera. When the night came, they had been doing VRI photometry of some symbiotic variable star. Then they turned the telescope on V838 Mon and took frame in I filter with 40cm Newtonian telescope. When the frame appeared they screamed "Ohh!" In the middle of the frame was saturated circle with diameter of 1/10 of field! They let down the exposition time, so the star was not saturated, but other stars were too faint to compare. Hence, they changed filter to V and on 17:45 UT the V838 Mon seemed to be a normal (it looked normal, they did not reduce this frame). They thought: "since discovery of N. J. Brown, the star had been slowly decreasing, so why should we do another observations? It is too boring for us". And they turned telescope to some RR Lyr star.

On 19:25 UT, L. Brat called them and was really exhilarated. He said what had happened and O. Pejcha and P. Sobotka almost killed themselves that they had stopped observations of V838 Mon! They immediately turned the telescope to V838 Mon again and on 19:33 UT started run in V filter with 20-second exposures. P. Sobotka's visual estimate on 20:12 UT 8.73 mag and O. Pejcha's on 20:13 UT 8.63 mag confirmed Brat's alert.

P. Sobotka and O. Pejcha reduced their first V frame made on 17:45 UT and find out brightness at 8.23 mag. During acquisition of new images they had been simultaneously reducing data which made them able to see the brightening in real time. On 22:15 UT they sent their report to IAUC. One hour later, they plot the light curve for the first time and saw unbelievable brightening with rate of 0,1 mag per hour!!! In this exciting night three other MEDUZA observers send their observations to VSNET. P.A.Dubovsky (visual), K.Hornoch (CCD+R) and L.Kral (CCD+R, visual).

Thanks to up-to-date technologies as cell phone and email, the information about outburst had been distributed to the majority of world observers and many observations were made during the same night around the whole world. Many thanks to all visual and CCD observers and thanks to VSNET alert mailling list!!!

Petr Sobotka, Ondrej Pejcha, Ladislav Smelcer and Lubos Brat