CBAT (IAU Circular 7785) Nicholas J. Brown, Quinns Rocks, W. Australia, discovers a possible nova in Monoceros on January 6.6 UT at about magnitude 10 on a T-Max 400 film. He confirmed it visually on January 7.6 UT at magnitude 10.0. R. M. Wagner etal..Hiltner 2.4-m Kitt Peak - object is ~same as red-mag 14.3 USNO-A2.0 - blend of two stellar objects. Spectrum is very complex and is "not typical of Fe- or He/N-type classical novae early in their evolution." (IAU Circular 7785). Spectra Jan 8; Osservatorio Astrofisico di Arcetri, Florence 1.22-m + Boller & Chivens spectrograph- "lacks typical signature of classic novae at maximum light or during early decline... object a peculiar 'slow' nova or a post-asymptotic-giant-branch star in flare-up. (IAU Circular 7786)
vsnet-alert 7064 : 2002 Jan 21 msg - possible nova in Mon (GSC 4822.39) Taichi Kato: "...only classical nova with K-type spectrum at maximum is V1148 Sgr in 1943 (Mayall AJ 54, 191) with rich metal + possibly TiO absorption lines... spectrum became emission-line five days later and suspected as special stage of explosive mass-loss event (cf. ApJ 353, 168 for a negative comment). Mon object may become emission-line at a later stage - spectroscopic follow-up obs important."
V
838 Mon comes good!
Astronomy
Now May 2003 / S&T June 2003 summarize the report in Nature
2003 March 27 by Howard E. Bond of Space Telescope Science Institute and
the evolution of this unique nova-like star - a binary system with a hot
B-type companion and red supergiant that has now cooled to a brown dwarf
like 1000C. At discovery by Nick Brown it proved ~1M brighter
than the Sun at a range of 20,000LY almost the distance of the Milky Way
core. The light echoes show progressive illumination of surrounding
halos ejected from previous outbursts as seen by Hubble ST.
Note:
The light curve over time gave a clue that this was not a regular nova
but my initial lo-res spectra below immediately affirmed this star was
'peculiar'.
Nova Aquila'01
my spectro page
WPO D7 image Feb 6
Scarmato
image Fujii
spectra Morata
spectra USNO
field Megastar
Summary - 2002 Jan 17 - Apr 10 -11 WPO observations @ disp=35A/pixel via 30cm SCT + Rainbow grating + MX9 CCD.
- 1] Initial spectra [2002 Jan 17/24] mimics K0-type Arcturus.
- 2] 2002 Feb 3/4/6 a 'smoothed' K-type profile but with strong Ha emission appearing.
- 3] On 2002 Feb 28 - Mar 4 Ha much reduced; the spectrum remarkably similar to V729 Cyg [type EB/D/GS; spectrum type 07F1A+O8; P=6.598d recorded at WPO on 1999 June 15].
- 4] 2002 Feb 4 - Apr 10 [first image below] the spectrum has shifted progressively into the red to a current [2002 Apr 10] quasi M-type spectrum with broad absorption bands but with Ha emission again dominating.
2002 Feb 28: Break in observations through poor weather and holiday in Tenerife. Spectra indicates that V838 Mon is possibly brighter than previously but the earlier Ha peak has vanished and replaced by a broad band of lesser peaks [He + H?] centred at 660nm - similar to pre-Ha outburst.
2002 Feb 3/4: V838 Mon has got much brighter in last 24 hours to ~M7.4 [from vsnet] and this evening, between downpours, a series of spectra finally showed a strong broad Ha emission line - 28 days after discovery. If V838 Mon is a nova it must be amongst the slowest in living memory.
2002 Jan 28: K-type spectrum
profile is changing-some maybe broad but weak emission[?] lines evolving.
Still no obvious classic Ha emission line.
2002 Jan 19/24: More spectra
during brief clear spells under a bright moon for a strong nova-like Ha
to appear but none recorded. Continued match for K-spectral type like Arcturus
[from WPO archive]. Spectral field image essentially R mag due to
grating's orange transmission colour - compare magnitudes with unfiltered
images below.
2002 Jan 15/17: First WPO
images and spectra of this odd star using nearby F- type Procyon for comparison.
Object star is radiating mostly at longer red wavelengths. The spectra
has weak emission lines but no strong lines like Ha
common
to classic novae.
Field image taken in a poorish seeing with object rising in ESE.
text & images copyright - Maurice Gavin - WPO - 2002