BRIGHT NOVA RETICULI 2020

Following the posting on the CBET 4811 & 4812 about the NOVA RETICULI 2020 we performed some follow-up of this object through a TEL 0.1-m f/3.6 astrograph + CCD located in the Heaven's Mirror Observatory, Australia (MPC code Q56) and operated by Telescope Live network.

On images taken on July 16.82, 2020 we can confirm the presence of an optical counterpart (with R-filtered magnitude about +4.5; B-filtered magn. +5.6; V-filtered magn. +5.6) at coordinates:

R.A. = 03 58 29.61, Decl.= -54 46 39.8

(equinox 2000.0; Gaia DR2 catalogue reference stars for the astrometry).

This transient was discovered by Robert H. McNaught (Coonabarabran, NSW, Australia) as an apparent 5th-magnitude nova on CCD images obtained on July 15.590 UT with a Canon 6D camera and an 8-mm-f.l. f/2.8 lens (at ISO 800). The position is very close to an object listed as "MGAB-V207" in the AAVSO's VSX online database (which gives position R.A. = 3h58m29s.55, Decl. = -54d46'41".2, equinox J2000.0, which calls it a novalike "VY Scl"-type variable with V magnitude range 15.8-18.0).

Spectroscopy by E. Aydi et al. (ATel #13867) using the High Resolution Spectrograph (HRS) mounted on the 11m Southern African Large Telescope as part of the SALT Large Science Program on Transients shows a spectrum that resembles that of a classical nova, likely after optical peak. Also, R. Kaufman (Bright, VIC, Australia) reports a low-resolution spectrum obtained by him on 2020 Jul. 16.62 UT (with a Canon 800D camera + 200-mm-f.l. f/3.5 lens) indicates the object to be a "Fe II-type" classical nova.

According to ATel #13868 "the positional coincidence of the optical/gamma-ray transient with the previously known VY Scl-type cataclysmic variable (d = 2.7 kpc from Gaia DR2; Bailer-Jones et al. 2018) suggests that the transient is a Galactic nova, which was confirmed with SALT spectroscopy (ATel #13867). It is only the third time that a classical nova eruption is observed in a previously known white dwarf hosting binary after V407 Cyg (ATel #2487) and V392 Per (ATel #11590), which were also detected by Fermi-LAT."

According to Cbet 4812 "the following pre-discovery V magnitudes from all-sky video images taken by M. A. Phillips at the Edward Pigot Seismic Observatory, Coonabarabran, using a ZWO ASI178MC-COOL color CMOS camera and a 1.4-mm-f.l. f/1.8 fish-eye lens: July 6.81, [6.0; 7.79, [5.5; 8.78, 5.4; 11.76, 3.7; 12.8, 3.8; 13.83, 4.0; 14.8, 4.4; 15.8, 4.7.  No variability was seen on single nights.  Further CCD magnitudes reported by McNaught from his images:  June 30.727, [9.8; July 1.763, [9.9; 2.826, [8.8; 15.747, 5.1; 15.785, 5.1; 15.804, 5.1. 

P. Schmeer, Bischmisheim, Germany, reports the following g magnitudes for the nova from the ASAS-SN Sky Patrol:  July 2.183, 16.6; 2.186, 16.3; 4.189, 15.5; 8.173, 6.8.  Schmeer adds that no previous outbursts or eruptions were recorded in ASAS-SN patrol images since 2014 June 18."

Below our confirmation image. Click on the image for a bigger version: 

An animation showing a comparison between my image and the archive POSS2/UKSTU Red plate (1993-12-17). 

by  Ernesto Guido, Marco Rocchetto & Adriano Valvasori

V659 SCUTI = NOVA SCUTI 2019

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Scutum (TOCP Designation: PNV J18395972-1025415) I performed some follow-up of this object through a TEL 0.6-m f/6.5 astrograph + CCD located in the El Sauce Observatory in Chile and operated by Telescope Live network.  

On images taken on October 31.01, 2019 I can confirm the presence of an optical counterpart with R-filtered CCD magnitude about +8.4 (saturated in a 10-second exposure) at coordinates:

R.A. = 18 39 59.71, Decl.= -10 25 41.9

(equinox 2000.0; Gaia DR2 catalogue reference stars for the astrometry).

This transient was discovered (discovered magnitude 11.5 g-Sloan Filter) by the All-Sky Automated Survey for Supernovae (ASAS-SN) on 2019 Oct. 29 at 01:12UT and reported to Transient Name Server (TNS) on Oct. 29 at 02:07:49 UTC as ASASSN-19aad = AT 2019tpb. According to CBET 4690, several independents discoveries have been reported to the Central Bureau of a nova in Scutum: Koichi Nishiyama (unfiltered magnitude 9.4 on Oct. 29.397), Hideo Nishimura (unfiltered magnitude 9.8 on Oct. 29.421), Shizuo Kaneko (unfiltered magnitude 9.8 on Oct. 29.462) (on AAVSO VSX is reported also Fujio Kabashima as independent discoverer). 

Spectroscopy by S. C. Williams et al. (see ATel #13241) & by  M. Pavana et al. (see ATel #13245) show that AT 2019tpb/ASASSN-19aad is a Galactic nova in the early stages of eruption.

N. Samus writes that the permanent GCVS designation V659 Sct has been assigned to this nova.

Below my confirmation image (sum of two unfiltered 30-sec exposure through a 0.6-m f/6.5 astrograph + CCD; El Sauce Observatory, Chile). Click on the image for a bigger version: 

An animation showing a comparison between my image and the archive POSS1 Blue plate (1951-07-30).

Below the same animation with a larger field of view. At the bottom left of V659 Sct you will notice a star occupying a different position in the new image with respect to the 1951 archive image. This star (Gaia designation DR2 4155146598548456064) is a high proper  motion star. Most stars are so distant that their apparent motion even over hundreds of years is all but negligible to naked eye observers. Some stars have very significant movements compared to the background stars (Click on it for a bigger version:

Below an image that is the difference between the new image and the archive image useful to highlight the "new" objects. There you can easily see the new galactic nova V659 Sct and the  high proper motion star.

by Ernesto Guido

Bright Transient in Carina

Following the posting on the ATel #11454 about the discovery by All Sky Automated Survey for SuperNovae survey (ASAS-SN) of a new transient source, possibly a classical nova, near the Galactic plane in Carina (ASAS-SN Designation: ASASSN-18fv) I performed some follow-up of this object through a 0.43-m f/6.8 astrograph + CCD from MPC Code Q62 (iTelescope Observatory, Siding Spring).

On images taken on March 23.4, 2018 I can confirm the presence of an optical counterpart with R-filtered CCD magnitude +5.7 at coordinates:

R.A. = 10 36 15.42, Decl.= -59 35 53.7

(equinox 2000.0; UCAC-4 catalogue reference stars).

Below you can see my confirmation image (single 20-sec exposure through a 0.43-m f/6.8 astrograph + CCD), click on it for a bigger version:

While below you can see a wide-field color image (90 second exposures) I obtained on March 23.4, 2018 through a Takahashi SKY90 Apochromatic Refractor f5/6 + Color CCD. In the image ASASSN-18fv is visible at the centre of the field together with part of the Carina Nebula (click on it for a bigger version):

This transient was discovered using data from the quadruple 14-cm "Cassius" telescope in CTIO, Chile of ASAS-SN survey on images obtained on UT 2018-03-20.32 at V<10 2018-03-16.32="" also="" asas-sn="" asassn-18fv="" at="" detected="" detection="" no="" on="" possibly="" saturated="" starting="" ut="" v="">17.0) of this object in subtracted images taken on UT 2018-03-15.34 and before by the same survey. No previous outbursts or variability are detected at the position of ASASSN-18fv since ASAS-SN started observing this location in February 2016. 

According to Atel #11467 pre-discovery images have been identified on images obtained by Evryscope-South, an array of 6-cm telescopes continuously monitoring 8000 square degrees of sky at 2-minute cadence from CTIO, Chile. The transient is not detected at UT 2018-03-16.0316 with an upper-limit of 11.9 +/- 0.1 mag (g'). Beginning at UT 2018-03-16.227, they detected a new source at 10.21 +/- 0.05 mag (g'). (click on the images below for a bigger version).

Credit: Evryscope

Credit: Evryscope

An animation showing a comparison between my confirmation image and the archive POSS2/UKSTU Red plate (1991-02-10). Click on it for a bigger version:

Spectroscopy by  P. Luckas (see ATel #11460) seems to indicate that ASASSN-18fv is a classical nova brightening and in the optically thick (Fe curtain) phase. 

But according to L. Izzo et al. (ATel #11468): "The lack of a strong blue continuum, that is however typical of classical nova outburst, and the low expansion velocities suggest a possible different nature for this object. The presence of many narrow absorptions also suggests a similarity with other peculiar explosions, like the luminous red variable V4332 Sgr (Martini et al. 1999), the possible luminous red novae V838 Mon and V1309 Sco (Tylenda et al. 2011, Mason et al. 2010) or the 'helium-flash' explosion observed in the Sakurai object (Duerbeck and Benetti 1996)". Doubts about the nova nature of this object were expressed also by J. Strader et al. (ATel #11456)

So further spectroscopic observations are important to clarify the nature of this very interesting transient.

by Ernesto Guido

Possible Nova in Circinus

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Circinus (TOCP Designation: PNV J13532700-6725110) I performed some follow-up of this object through a TEL 0.43-m f/6.8 reflector + CCD from MPC Code Q62 (iTelescope Observatory, Siding Spring). 

On images taken on January 20.6, 2018 I can confirm the presence of an optical counterpart with R-filtered CCD magnitude +8.09 & V-filtered CCD magnitude +8.33 at coordinates: 

R.A. = 13 53 27.57, Decl.= -67 25 01.0 

(equinox 2000.0; Gaia DR1 catalogue reference stars for the astrometry).

This transient has been reported to CBAT/TOCP by John Seach, Chatsworth Island, NSW, Australia. Discovery made with a DSLR with 50 mm f/1.2 lens.

Below my confirmation image (single unfiltered 60-sec exposure through a 0.43-m f/6.8 reflector + CCD; MPC Code Q62). Click on the image for a bigger version: 

An animation showing a comparison between the confirmation image and the archive POSS2/UKSTU Red plate (1997-03-31). Click on the animation for a bigger version: 

UPDATE - January 31, 2018

According to CBET 4482 issued on January 30, Spectroscopy by Strader et al., obtained with the 4.1-m Southern Astrophysical Research Telscope (+ Goodman spectrograph) at Cerro Pachon, Chile, on Jan. 21.28 UT shows clear P-Cyg profiles in the Balmer lines, with the absorption troughs located about 1300 km/s blueward of the rest wavelength (emission FWHM about 1500 km/s), and a number of Fe II lines (some of which also have P-Cyg profiles) -- suggestive of a "Fe II"-type nova. See also ATel #11209. While a low-resolution spectroscopic image by S. Kiyota that shows a strong hydrogen emission line is available here.

This nova has been designated NOVA CIRCINI 2018.

by Ernesto Guido

Possible Bright Nova in Musca

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Musca (TOCP Designation: PNV J11261220-6531086) we performed some follow-up of this object through a TEL 0.50-m f/6.8 reflector + CCD + focal reducer from MPC Code Q62 (iTelescope Observatory, Siding Spring).

On images taken on January 15.57, 2018 we can confirm the presence of an optical counterpart with R-filtered CCD magnitude ~6.3 at coordinates:

R.A. = 11 26 14.95, Decl.= -65 31 24.1

(equinox 2000.0; Gaia DR1 catalogue reference stars).


This transient has been reported to CBAT/TOCP by Rob Kaufman, Bright, Victoria, Australia. Discovery image (taken with Canon 650D & 55mm lens) is available here. He also posted a low-resolution spectrum that "shows strong hydrogen emissions as well as FeII lines":

Credit: R. Kaufman

Below you can see our confirmation image (single 30-sec exposure through a 0.43-m f/6.8 reflector + CCD), click on it for a bigger version:

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU Red plate (1998-03-19). Click on it for a bigger version:

UPDATE - January 16, 2018

According to CBET 4472 this transient could be a classical "Fe II"-type nova and it has been designated NOVA MUSCAE 2018.

by Ernesto Guido & Alfonso Noschese

Possible Nova in Cepheus

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Cep (TOCP Designation: PNV J23080471+6046521) we performed some follow-up of this object remotely through the 0.43-m f/6.8 reflector + CCD of ITelescope network (MPC Code  I89 - Nerpio, Spain). 

On our images taken on February 02.8, 2013 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 9.8 at coordinates:

R.A. = 23 08 04.70, Decl.= +60 46 52.0

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

Our annotated confirmation image (click on it for a bigger version):

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1991). Click on the thumbnail for a bigger version:

Kazuyoshi Imamura (Okayama Univ. of Sci. team, JAPAN) reports on vsnet-alert mailing list that they "succeeded in obtaining a low-resolution spectrum (R~400) of the PNV J23080471+6046521 (in Cep) on February 2.526 UT at the OUS (Okayama Univ. of Sci.) observatory......From our result, this object is thought to be a classical nova (Fe II class)"

Credit: K. Imamura (Okayama Univ. of Sci. team, JAPAN)

UPDATE - February 03, 2013

According to Cbet No. 3397, PNV J23080471+6046521 is now NOVA CEPHEI 2013. This nova has been discovered by Koichi Nishiyama and Fujio Kabashima (Japan) on two 40-s unfiltered CCD frames (limiting magnitude 13.5) taken around Feb. 2.4119 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera). Spectra confirming the nature of the nova have been obtained by K. Imamura (see above) and M. Fujii (Bisei Astronomical Observatory).

Ernesto Guido & Nick Howes

NOVA SAGITTARII 2012 No. 4

Cbet 3166, issued on 2012 July 07, reports the discovery by Koichi Nishiyama and Fujio Kabashima (Japan) of a possible nova (mag 7.8) on two 40-s unfiltered CCD frames (limiting magnitude 13.7) taken around July 7.4986 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera). The variable was designated PNV J18202726-2744263 when it was posted at the Central Bureau's TOCP webpage.

The nova has been designated NOVA SAGITTARII 2012 No. 4.

We performed some follow-up of this object remotely through the 2.0-m  f/10.0 Ritchey-Chretien + CCD of "Faulkes Telescope South" (MPC Code - E10). On our images taken on July 09.4, 2012 we can confirm the presence of an optical counterpart with R-filtered CCD magnitude 8.7 at coordinates:

R.A. = 18 20 27.20, Decl.= -27 44 26.2

(equinox 2000.0; CMC-14 catalogue reference stars).

Our annotated confirmation image. Click on it for a bigger version:

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1996). Click on the thumbnail below:

Spectra obtained by different observers (M. Fujii; K. Imamura; C. Buil) indicate that the variable is a "Fe II"-class nova

Spectrum by K. Imamura (OUS)

by E. Guido, N. Howes, M. Jenkins, J. Hodge & G. Sostero

Another Possible Nova in Oph

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Oph (TOCP Designation: J17395600-2447420) we performed some follow-up of this object remotely through the 0.43-m f/6.8 astrograph + CCD of ITelescope network (MPC Code - H06).

On our images taken on May 20.3, 2012 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 9.5 at coordinates:

R.A. = 17 39 57.00,  Decl.= -24 47 07.3

(equinox 2000.0; CMC-14 catalogue reference stars).

Below you can see  animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1996). Click on the thumbnail for a bigger version:

Our confirmation image. Click on it for a bigger version:

UPDATE - May 28, 2012

According to Cbet 3124, this variable has been designated NOVA OPHIUCHI 2012 No. 2. This nova was discovered by John Seach, Chatsworth Island, NSW, Australia, on six images (limiting mag 11.0) taken on May 19.484 UT with a digital SLR camera (+ 50-mm f/1.0 lens). Spectra obtained by different observers (T. Bohlsen, W. Vollmann, K. Imamura, F. M. Walter, C. Buil) suggests that the object is a classical nova.

Spectrum by K. Imamura (OUS)

by Ernesto Guido, Giovanni Sostero & Nick Howes

Possible Nova in Sgr

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Sgr (TOCP Designation: PNV J17452791-2305213) we performed some follow-up of this object remotely through 0.25-m f/3.4 reflector + CCD from MPC code H06 (Mayhill station, NM).

On our images taken on April 22.4, 2012 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 9.1  at coordinates:

R.A. = 17 45 28.02, Decl.= -23 05 23.2

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

According to VIZIER there is a 16.21 R1-magnitude star at 0.237 arcseconds from the transient position (USNO-B1.0 0669-0621295).

Our confirmation image (click on it for a bigger version):

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1996). Click on the thumbnail for a bigger version:

UPDATE - April 25, 2012

According to Cbet 3089, spectra obtained by Christian Buil and Kazuyoshi Imamura, Okayama University of Science (OUS) shows emission lines of H-alpha. The transient appears to be a classical nova. This nova, designated NOVA SAGITTARII 2012, has been discovered by Stanislav Korotkiy and Kirill Sokolovsky, on three 30-s unfiltered CCD images (limiting magnitude about 14.0) obtained on Apr. 21.011 UT with a wide-field survey camera (+ 135-mm-f.l. f/2 telephoto lens + ST8300M camera) at Ka-Dar Observatory's TAU Station near Nizhny Arkhyz, Russia.


by Ernesto Guido, Nick Howes & Giovanni Sostero

Another Possible Nova in Cen

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Cen (TOCP Designation: J14250600-5845360) we performed some follow-up of this object remotely through the 2.0-m  f/10.0 Ritchey-Chretien + CCD of "Faulkes Telescope South" (MPC Code - E10).

On our images taken on April 09.5, 2012 we can confirm the presence of an optical counterpart with Bessell-R CCD magnitude 8.7 at coordinates:

R.A. = 14 25 04.45, Decl.= -58 45 34.3

(equinox 2000.0; UCAC-2 catalogue reference stars).

According to VIZIER there is a 15.319 J-magnitude star at 2.6 arcseconds from the transient position (NOMAD1 0312-0489482). 

Our confirmation image (click on it for a bigger version):

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1997). Click on the thumbnail below for a bigger version:

UPDATE - January 30, 2018

Apparently, while this object has been confirmed as a nova on spectra taken by T. Bohlsen, no permanent designation by GCVS has been assigned to this transient. See also here & here. 


by Ernesto Guido, Nick Howes & Giovanni Sostero

Possible Nova in Ophiuchus

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Oph (TOCP Designation: PNV J17260708-2551454) we performed some follow-up of this object remotely through the 0.10-m f/5 reflector + CCD from MPC code H06 (Mayhill station, NM) of iTelescope network.

On our images taken on 2012, March 27.5 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 10.9 at coordinates:

R.A. = 17 26 07.02, Decl.= -25 51 42.1

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

Our confirmation image:

While below you can see an animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1997). Click on the thumbnail for a bigger version:

UPDATE - MARCH 29, 2012

According to Cbet 3072 issued on March 28, observers at Koyama Astronomical Observatory (KAO) and at Okayama University of Science (OUS) have obtained a spectra of this variable star. An H-alpha emission line can be seen in the spectrum. H_beta, Fe II, and O I 777.4-nm are also visible. These features suggest that the object is an "Fe II-type" classical nova. This nova, designated NOVA OPHIUCHI 2012, has been discovered by Hideo Nishimura (Miyawaki, Kakegawa, Shizuoka-ken) on three 13-s frames (limiting mag 13.5) taken on Mar. 25.789 UT with a Canon 200-mm f/3.2 lens and a Canon EOS 5D Digital Camera mounted on a Takahashi EM100 equatorial telescope at Gomyo, Kakegawa, Japan.

by Ernesto Guido, Giovanni Sostero & Nick Howes

Possible Nova in Centaurus

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Cen (TOCP Designation: PNV J13410800-5815470) we performed some follow-up of this object remotely through the 2.0-m  f/10.0 Ritchey-Chretien + CCD of "Faulkes Telescope South" (MPC Code - E10).

On our images taken on March 24.5, 2012 we can confirm  the presence of an optical counterpart with filtered  R-Bessel CCD magnitude 9.3 (USNO-B1.0 Catalogue reference stars) at coordinates:

R.A. = 13 41 09.36, Decl.= -58 15 16.9

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

Our confirmation image (click on it for a bigger version):

While below you can see an animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1994). Click on the thumbnail for a bigger version:

UPDATE - MARCH 29, 2012

According to Cbet 3073 issued on March 29, F. M. Walter, Stony Brook University, obtained a low-resolution (0.31-nm) red (560-690 nm) spectrogram of PNV J13410800-5815470 on Mar. 27.3 UT using the SMARTS 1.5-m telescope (+ RC spectrograph) at Cerro Tololo. The variable is a classical "Fe II"-type nova. This nova, designated NOVA CENTAURI 2012, has been discovered by John Seach, Chatsworth Island, NSW, Australia,  on six images (limiting mag 11.0) taken on Mar. 23.386 UT with a digital SLR camera (+ 50-mm f/1.0 lens).

by Ernesto Guido, Alison Tripp, Nick Howes and Giovanni Sostero

NOVA SCORPII 2011 No. 2

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible transient in Sco  (TOCP Designation: PNV J16364300-4132460) and AAVSO Special Notice #251, we performed some follow-up of this object  remotely through the 2.0-m f/10.0 Ritchey-Chretien + CCD of "Faulkes Telescope South" (MPC Code - E10).

The two independent discoverers of this nova are: John Seach (Australia) and Yuji Nakamura (Japan).

On our images taken on September 07.50, 2011 we can confirm  the presence of an optical counterpart with filtered R-Bessel CCD magnitude 9.1 (USNO-B1.0 Catalogue reference stars) at coordinates:

R.A. = 16 36 44.29, Decl.= -41 32 37.7

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

According to VIZIER there is a 15.08 R1 magnitude star at 0.060 arcseconds from the transient position (USNO-B1.0 0484-0459316).

Our BRV image (click on it for a bigger version):

Below you can see an animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1997). Click on the thumbnail for a bigger version: 

A. Arai, T. Kajikawa, C. Naka, Kyoto Sangyo University, reports on Cbet 2813 that they performed low-resolution optical spectroscopic observations (R about 580) of this object on Sept. 7.42 UT using the Araki telescope at Koyama Astronomical Observatory.  The spectrum exhibits broad Balmer emissions and Fe II multiplet emissions on a highly reddened continuum light.  The H-alpha emission line shows an asymmetric profile with FWZI about 6000 km/s. These features suggest that the object is an "Fe II"-type classical nova, highly reddened by the interstellar medium.

by Ernesto Guido, Nick Howes and Giovanni Sostero

NOVA SCORPII 2011

CBET circular No. 2735, issued on June 03, 2011, announces the discovery by John Seach (Australia) of a possible nova (mag 9.5) on three CCD images (limiting mag 11.0) taken on June 1.40 UT with a digital SLR camera (+ 50-mm-f.l. f/1.2 lens + orange filter).

We performed some follow-up of this object remotely with the GRAS RCOS 32-cm f/6.3 telescope at Officer, Australia. On our images taken on June 02.4, 2011 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 9.4 (USNO-B1.0 Catalogue reference stars) at coordinates:

R.A. = 16 55 09.46, Decl.= -38 38 04.5

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

Our confirmation image (click for a bigger version):

Below you can see an animation showing a comparison between our confirming image and the archive POSS2/UKSTU plate (R Filter - 1995). Click on the thumbnail below for a bigger version:

CBET circular No. 2735 also reports that A. Arai, T. Kajikawa, and M. Nagashima, Kyoto Sangyo University, performed low-dispersion optical spectroscopic observations (range 400-750 nm; R about 600) of this transient on June 2.68 UT using the 1.3-m Araki telescope (+ LOSA/F2) under a hazy sky. The spectrum shows a broad H-alpha (FWZI about 4600 km/s) with an asymmetric profile and O I (777.4 nm) on a highly-reddened continuum. No visible He or Fe II lines exist in the spectrum. These features suggest that the object is a classical nova in outburst with high interstellar reddening.

(Credit: A. Arai, T. Kajikawa, and M. Nagashima)

by Ernesto Guido and Giovanni Sostero

Possible Nova in Scorpius

CBET circular No. 2262, issued on April 26, 2010, announces the discovery by K. Nishiyama & F. Kabashima (Japan) of another possible nova (mag 8.6) on two 40-s unfiltered CCD frames (limiting magnitude 13.1) taken around Apr. 25.788 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera). The same CBET reports indipendent discovery by H. Nishimura & T. Kojima.

We performed some follow-up of this object remotely through a 0.25-m, f/3,4 reflector + CCD, from GRAS Observatory (near Mayhill, NM).

On our images taken on April 26.4, 2010 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 8.2 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 16 55 13.17, Decl.= -38 03 47.8

(equinox 2000.0; UCAC2 catalogue reference stars).

Our confirmation image:

This is an animation showing a comparison between our image and the archive DSS plate (R Filter - 1995). Click on it for a bigger version.

UPDATE - MAY 06, 2010

According to IAUC circular No. 9142, a low-dispersion spectrum (range 420-850 nm, resolution about 500) of this object, taken by K. Kinugasa, H. Takahashi, and O. Hashimoto on Apr. 29.745 UT with the GAO 1.5-m telescope (+ GLOWS), shows broad (FWHM about 4000 km/s) Balmer and O I (777.4-, 822.7-, and 844.6-nm) emission lines. The features indicate that the object is a He/N nova in a declining phase.

The permanent GCVS designation V1311 Sco has been assigned to this nova.

V1311 SCORPII = NOVA SCORPII 2010 No. 2

by Ernesto Guido and Giovanni Sostero

Possible Nova in Sagittarius

CBET circular No. 2261, issued on April 24, 2010, announces the discovery by K. Nishiyama & F. Kabashima (Japan) of a possible Milky Way nova (mag 11.2) in Sagittarius on two 40-s unfiltered CCD frames (limiting magnitude 13.2) taken around Apr. 23.782 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera).

We performed some follow-up of this object remotely through a 0.25-m, f/3,4 reflector + CCD, from GRAS Observatory (near Mayhill, NM).

On our images taken on April 25.4, 2010 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 12.1 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 17 53 02.99, Decl.= -28 12 19.3

(equinox 2000.0; UCAC2 catalogue reference stars)

Our confirmation image:

This is an animation showing a comparison between our image and the archive DSS plate (IR Filter - 1980). Click on it for a bigger version.

Spectroscopic observations are required to confirm the real nature of this transient.

UPDATE - May 06, 2010

According to IUAC 9140, a spectra has been obtained at the Steward Observatory Bok 2.29-m telescope on Apr. 25.4 UT by L. A. Helton, T. Vonderharr, and C. E. Woodward and G. J. Schwarz. These observations confirm that this is a post-maximum classical nova. The spectra exhibit strong, broad H_alpha emission.

The permanent GCVS designation V5586 Sgr has been assigned to this nova.

V5586 SAGITTARII = NOVA SAGITTARII 2010 No. 2

by Ernesto Guido and Giovanni Sostero

Possible Nova in Scorpius

Following the posting on the Central Bureau's unconfirmed-objects webpage about a possible nova in Sco, on February 22.8, 2010 we performed some follow-up of this object remotely through through a 0.40-m, f/3.8 reflector + CCD, from GRAS Observatory (Moorook, Australia).

On our images we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 10.1 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 17 06 07.50, Decl.= -37 14 27.7
(equinox 2000.0; UCAC2 catalogue reference stars)

Our confirmation image:

This is an animation showing a comparison between our image and thearchive DSS plate:

Spectroscopic observations are required to confirm the real nature of this transient.

UPDATE - February 24, 2010

According to Cbet No 2183 this transient in Scorpius has been discovered by Koichi Nishiyama and Fujio Kabashima (Japan) on two 40-s unfiltered CCD frames (limiting magnitude 12.7) taken around Feb. 20.857 UT using a 105-mm f/4 camera lens (+ SBIG STL6303E camera).

On Cbet 2186 (issued on February 23), K. Ayani (BAO) reported that a low-resolution spectrum (range 400-800 nm; resolution 0.5 nm at H-alpha) of the probable nova was obtained with the BAO 1-m telescope on Feb. 23.88 UT. This shows prominent H-alpha emission with P-Cyg absorption upon a red continuum. These features show that the new object is a "Fe II"-type nova.

The transient is officially NOVA SCORPII 2010.

by Ernesto Guido and Giovanni Sostero

Nova Ophiuchi 2010 (No. 2)

CBET circular No. 2176, issued on February 19, 2010, announces the discovery by Hideo Nishimura (Japan) of a possible nova (mag 9.4) in Ophiuchus on two 13-s frames taken on Feb. 18.845 UT using a Minolta 120-mm f/3.5 lens and a Canon EOS 5D Digital camera.

On our images taken on February 20.5, 2010 through a 0.25-m, f/3,4 reflector +CCD, from GRAS Observatory (near Mayhill, NM), we can confirm the presence of an optical counterpart with unfiltered CCD magnitude about 9.4 (UCAC2 Catalogue reference stars) at coordinates:

R.A. = 17 26 32.15, Decl.= -28 49 41.8
(equinox 2000.0; UCAC2 catalogue reference stars).

According to Nishimura nothing is visible at this position on his survey frames taken during each month in the span 2009 Feb.-Oct. 15 and on 2010 Feb. 2, 4, 5, 7, and 13.84 UT (limiting mag 11).

Our confirmation image:

This is an animation showing a comparison between our image and the archive DSS plate:

On Vsnet mailing list Imamura-san (Okayama U. of Sci.) and Fujii-san have reported spectra of this object confirming it as a nova:

According to Taichi Kato "Halpha emission was accompanied by a P Cyg absorption (blue-shifted by1000 km/s). Balmer emission lines with P Cyg profiles (700 km/s for Halpha) and Fe II lines were visible."

by Ernesto Guido & Giovanni Sostero

U Scorpii in Outburst

The recurrent nova U Sco has been discovered in outburst at magnitude V=8.05 on January 28.4385 UT by amateur astronomers B. Harris and shortly after by S. Dvorak (who estimated it at V~8.8). According to the AAVSO website prior to outburst, U Scorpii was measured at V=18.2 on Jan 27.4501 (Harris), and estimated at m(vis) less than 16.5 on January 27.6271 by M. Linnolt.

Novae are binary systems where the companion star feeds matter through an accretion disk to accumulate on a white dwarf. After the eruption, the white dwarf returns to a steady state while the accumulation begins anew so that all novae recur. Each white dwarf will undergo many such eruptions, with the typical timescale between eruptions perhaps as long as 100,000 yr, although a subset of the nova population (called recurrent novae [RNe]) has recurrence timescales from 10 to 100 yr.

U Sco is one of the most famous recurrent novae. In quiescence it usually hovers around magnitude 17.6, but in outburst it briefly shoots up by about 8 or 9 magnitudes. In fact, U Sco is the all-time fastest nova known. Its brightening from minimum to maximum takes only about 5 hours, and its decline to two magnitudes below maximum takes about 38 hours. U Sco's last three eruptions, in 1979, 1987, and 1999, were all discovered by amateur astronomers.

One year ago, Bradley Schaefer predicted that the recurrent nova U Scorpii was due to explode again in April 2009 ± 1.0 year. Schaefer searched the old photographic sky-patrol plates stored at the Harvard College Observatory to discover three more eruptions of U Sco. With these, the pattern of eruption since 1900 has been once every 10 ± 2 years. (Eruptions were likely missed around 1927 and 1957 because Scorpius is hidden in conjunction with the Sun every November and December). Moreover, for his prediction, Schaefer used the system's brightness in quiescence (slightly variable) as a measure of the rate at which matter is falling onto the white dwarf.

Using a remote scope located in Australia, we have been able to image U Sco in outburst on Jan. 28.73:

Below you can see a comparison image showing the field of U Sco imaged by us on April 2009 when it was below the magnitude 17 and the same field imaged few hours ago on January 28, 2010:

On Vsnet mailing list T. Kato reports that Imamura-san (Okayam U. of Sci.) and Fujii-san have obtained spectra of U Sco on January 28.8. Kato comments that P Cyg-type components having a velocity of 4300 km/s for Halpha (Fujii). The lines of He I and N II were strong (also associated with P Cyg-type components). The FWHM of Halpha was 6100 km/s (Imamura).

(Credit: Fujii)

Within an hour of the discovery, U Sco had already be observed by two X-ray satellites (the Rossi X-Ray Timing Observatory and the INTEGRAL satellite). In the following weeks the recurrent nova will be observed by many ground-based telescopes and spaceborne observatories.

These observations will help to answer some questions about the suspected link between RNe and Type Ia SNe. Although it seems that for systems like RS Oph and U Sco, the mass of the White Dwarf (WD) is near the Chandrasekhar limit and increasing, there remain some fundamental questions. For example, what is the type of the WD (if ONe, then no SN explosion will occur); can the Hydrogen in systems with red giant secondaries really be “hidden” at the time of any SN outburst; is the population of (appropriate sub-type) RNe sufficient to explain the observed SN Ia rate? A combination of detailed observations of individual Galactic RNe, coupled with surveys of extragalactic novae, will help to answer these very important points. (Bode, 2009).

By Ernesto Guido & Giovanni Sostero