Nova Delphini 2013 = V339 Del (formerly PNV J20233073+2046041): images, spectra and maps

Last update: 11 Oct. 2013, 09:30 UT

V339 Delphini (= Nova Delphini 2013): brightness evolution

Nova Delphini 2013: variation between 18 Aug (max), 12 Sept. and 10 Oct.

Possible nova PNVJ20233073+2046041: 14 Aug. 2013

Nova Del 2013: light curve

Above is the podcast from our Nova del 2013 live session

Note (15.4 Aug 2013): this object was officially classified as a nova on CBET 3628 (accessible by subscription), where the nature of the nova was unveiled by our spectroscopy!

At a glance:

• 10.83 Oct. 2013, the Nova was found at mag. 9.0R
• 14.92 Sept. 2013, the Nova was found at mag. 6.1R
  
• 13.78 Sept. 2013, the Nova was found at mag. 6.2R
  
• 12.79 Sept. 2013, the Nova was found at mag. 6.5R
  
• 07.89 Sept. 2013, the Nova was found at mag. 6.4R
• 05.81 Sept. 2013, the Nova was found at mag. 6.3R
• 04.82 Sept. 2013, the Nova was measured at mag. 6.2R
• 04.52 Sept. 2013, the Nova received the permanent designation V339 DELPHINI
• 03.87 Sept. 2013, the Nova was measured at mag. 6.3R
• 02.89 Sept. 2013, the Nova was measured at mag. 6.4R
• 01.92 Sept. 2013, the Nova was measured at mag. 6.5R
• 31.97 Aug. 2013, the Nova was measured at mag. 6.3R
• 30.92 Aug. 2013, the Nova was found at mag. 6.1R
• 29.91 Aug. 2013, the Nova was found again at mag. 6.0R
• 28.81 Aug. 2013, the Nova was found at mag. 6.0R
• 27.84 Aug. 2013, the star was at mag 5.8R, still fading.
• 26.90 Aug. 2013, very bad weather, no observations.
• 25.97 Aug. 2013, the star was spotted at mag 6.3R (bad weather)
• 24.84 Aug. 2013, the Nova was found again at mag 5.6R,
• 23.91 Aug. 2013, the Nova was found at mag 5.6R, clearly fading.
• 22.96 Aug. 2013, the star was at mag 5.5R, still fading.
• 21.78 Aug. 2013, the star was at mag 5.4R, slowly fading.
• 20.77 Aug. 2013, the Nova was found at mag 5.2R, likely confirming a fading trend.
• 19.82 Aug. 2013, the Nova is at mag 5.0R, likely a bit fainter than yesterday.
• 18.83 Aug. 2013, the Nova is still at mag 4.8R, sitting on its plateau.
• 17.80 Aug. 2013, the Nova was found at mag 4.8R, similar to last night.
• 16.95 Aug. 2013, the Nova was bright  sight with a 10×50 bino, mag 4.5 or so from Rome.
• 16.8 Aug. 2013, the Nova was at mag. 4.9R, brighther than last night.
• 16.5 Aug. 2013, the Nova is reported to be at mag 4.0, a very feasible naked eye sight.
• 15 .884 Aug. 2013, the star was at mag 5.3R, so quite brighter than at the discovery!
• 14.92 Aug. 2013, the Virtual Telescope recorded hydrogen emission, suggesting the nova nature.
• 14.89 Aug. 2013, the Virtual Telescope confirmed the existence of the transient at mag. 6.8R.
• 14.758 Aug. 2013, the discovery of  this nova was announced by K. Itagaki.

– 10 Oct. 2013 –

Tonight, Nova  Del 2013 was found at magnitude  9.0R,  about three mags fainter than last observations, one month ago. As always both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 10 Oct. 2013

Spectroscopy shows evident evolution, compared to one month ago (for example, a new feature developed between H-gamma and H-beta):

Spectrum of Nova Del 2013: 10 Oct. 2013

– 4 Sept. 2013 –

Tonight, Nova  Del 2013 was found at magnitude  6.2R,  confirming some brightening over the very last nights. As always both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 04 Sept. 2013

Spectroscopy is still dominated by a strong Balmer emission and other features:

Spectrum of Nova Del 2013: 4 Sept. 2013

– 3 Sept. 2013 –

Tonight, Nova  Del 2013 was found at magnitude  6.3R,  marginally brighter than last night. As always both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 03 Sept. 2013

Spectra are still showing many interesting features, even at low resolution:

Spectrum of Nova Del 2013: 3 Sept. 2013

– 2 Sept. 2013 –

Tonight, Nova  Del 2013 was found at magnitude  6.4R,  as bright (or marginally brighter) than last night. As always both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 02 Sept. 2013

Spectroscopy is still dominated by a strong Balmer emission and other features:

Spectrum of Nova Del 2013: 2 Sept. 2013

– 1 Sept. 2013 –

Tonight, Nova  Del 2013 was found at magnitude  6.5R, the star seems to fade quicker than in the past week . As always both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 01 Sept. 2013

Spectroscopy is still dominated by a strong Balmer emission and other features:

Spectrum of Nova Del 2013: 1 Sept. 2013

– 31 Aug. 2013 –

This night, Nova  Del 2013 was found at magnitude  6.3R, along its fading trend. As always both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 31 Aug. 2013

Spectroscopy is still dominated by a strong Balmer emission and other features:

Spectrum of Nova Del 2013: 31 Aug. 2013

– 30 Aug. 2013 –

The sky was clear for some time and the nova  was found at magnitude  6.1R, so it dropped a bit in brightness. As always both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 30 Aug. 2013

Spectroscopy still shows an amazing H-alpha emission and other features as in the last nights:

Spectrum of Nova Del 2013: 30 Aug. 2013

– 29 Aug. 2013 –

The sky was clear for some time and the nova  was found at magnitude  6.0R, as yesterday, like a temporary pause in the fading trend. Again both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 29 Aug. 2013

Spectroscopy provided again some excellent results, with the Balmer emission getting stronger and stronger and evidence of several other elements:

Spectrum of Nova Del 2013: 29 Aug. 2013

– 28 Aug. 2013 –

The sky was clear and the nova  was found at magnitude  6.0R, a bit fainter than yesterday. Again both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 28 Aug. 2013

Spectroscopy provided again some excellent results, with the Balmer emission getting stronger and stronger and evidence of several other elements:

Spectrum of Nova Del 2013: 28 Aug. 2013

– 27 Aug. 2013 –

Using a short break in the clouds, the nova  was found at magnitude  5.8R, this suggesting that the previous 25 Aug. estimate was affected by atmosphere. Again both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures: the star is the brightest object, at the center of the frame:

Nova Del 2013: 27 Aug. 2013

Spectroscopy provided some excellent results, with the Balmer emission getting stronger and stronger and evidence of several other elements:

Spectrum of Nova Del 2013: 27 Aug. 2013

– 25 Aug. 2013 –

Tonight the nova  was found at magnitude  of 6.3R, with sky conditions not ideal because of transiting clouds. Both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures, with  interference by the Moon: the star is the brightest object, at the center of the frame:

Nova Del 2013: 25 Aug. 2013

Spectra tonight are  a bit blurred because of the less than ideal seeing, but the main features are well apparent:

Spectrum of Nova Del 2013: 25 Aug. 2013

– 24 Aug. 2013 –

Tonight the nova  showed again magnitude  of 5.8R, as yesterday. Both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures, with  interference by the Moon: the star is the brightest object, at the center of the frame:

Nova Del 2013: 24 Aug. 2013

The new spectrum confirms the recent situation, with Balmer emission likely increasing:

Spectrum of Nova Del 2013: 24 Aug. 2013

– 23 Aug. 2013 –

Tonight the nova  showed a magnitude  of 5.8R, significantly fainter than yesterday. Both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures, with  interference by the Moon: the star is the brightest object, at the center of the frame:

Nova Del 2013: 23 Aug. 2013

The spectrum continues to show a strong dominance of Balmer emission, as seen on the last few days:

Spectrum of Nova Del 2013: 23 Aug. 2013

– 22 Aug. 2013 –

At he beginning of the evening, the nova  showed a magnitude  of 5.5R, confirming a fading trend. Both the remote PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures, with a strong interference by the full Moon: the star is the brightest object, at the center of the frame:

Nova Del 2013: 22 Aug. 2013

Spectra showed again a very strong H-alpha emission, higher than ever, as well as a nice H-beta signature. Other details appear, the spectrum is greatly evolving:

Spectrum of Nova Del 2013: 22 Aug. 2013

– 21 Aug. 2013 –

At he beginning of the evening, the nova  showed a magnitude  of 5.4R, likely confirming the fading trend. Both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures, with a strong interference by the full Moon: the star is the brightest object, at the center of the frame:

Nova Del 2013: 21 Aug. 2013

Spectra showed again a very strong H-alpha emission, higher than ever, as well as a nice H-beta signature. Other details appeared, the spectrum is clearly evolving:

Spectrum of Nova Del 2013: 21 Aug. 2013

– 20 Aug. 2013 –

Early in the 20 Aug. evening, the nova  showed a magnitude  of 5.3R, likely confirming a fading trend. Both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 9, 10-seconds unfiltered exposures, with a strong interference by the full Moon: the star is the brightest object, at the center of the frame:

Nova Del 2013: 20 Aug. 2013

Spectra showed a very strong H-alpha emission, never seen so peaked so far. Also H-beta is showing and another broad feature centered at 5320 Angstrom:

Spectrum of Nova Del 2013: 20 Aug. 2013

– 19 Aug. 2013 –

We run our online event on this star, showing it to the public.  It showed a magnitude  of 5.0R, so a bit fainter, than last night. Both the PlaneWave 17″ and Celestron C14 robotic units were used for these observations.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures, the star is the brightest object, at the center of the frame:

Nova Del 2013: 19 Aug. 2013

The spectrum looked very different from previous nights: the H-alpha emission was very strong:

Spectrum of Nova Del 2013: 19 Aug. 2013

– 18 Aug. 2013 –

The star reached a plateau in its brightness when we observed  it again, both with the PlaneWave 17″ and Celestron C14 robotic units. The measured magnitude was 4.8R, as last night.

Below is an image taken with the PlaneWave 17″ unit, after the average of 5, 10-seconds unfiltered exposures, the star is the brightest object, at the center of the frame:

Nova Del 2013: 18 Aug. 2013

A new spectrum showed a strong emission in H-alpha:

Spectrum of Nova Del 2013: 18 Aug. 2013

– 17 Aug. 2013 –

The star was told to have reached its peak in brightness, so we wanted to measure it again, both with the PlaneWave 17″ and Celestron C14 robotic units. The measured magnitude was 4.8R, so at the same level of last night.

Below is a screenshot taken during the imaging session with the PlaneWave 17″:

Nova Del 2013, a screenshot: 17 Aug. 2013

Also, a color image was obtained via RGB combining three monochromatic files and the results is shown below:

Nova Delphini 2013: a color view – 17 Aug. 2013

Below is a spectrum, where the H-alpha emission is for some reason sot evident as in the previous days:

Spectrum of Nova Del 2013: 17 Aug. 2013

– 16 Aug. 2013 –

For the third night in a row, Nova Del 2013 was observed again, both with the PlaneWave 17″ and Celestron C14 robotic units to capture new spectra and new photometry.

The star showed at mag of 4.9R, so significantly brighter than the previous night and likely reached its magnitude peak. Again, the star was easy (and brighter) with a 10×50 binocular, even from Rome: the magnitude increase was evident since the first glance.

Below is an image taken with the PlaneWave 17″ unit, after the average of 10, 10-seconds unfiltered exposures, the star is the brightest object, at the center of the frame:

Nova Del 2013: 16 Aug. 2013

The Celestron C14 unit was used to capture a color image of the Nova and it showed a nice white color:

Nova Delphini 2013 in color: 16 Aug. 2013

Finally, a new spectrum showed a strong emission in H-alpha, while the H-beta is apparently fading:

Spectrum of Nova Del 2013: 16 Aug. 2013

– 15 Aug. 2013 –

Nova Del 2013 was observed again, both with the PlaneWave 17″ and Celestron C14 robotic units to capture new spectra and new photometry.

The star was found at mag 5.3R,  almost one mag. brighter than the previous night, so it increased significantly its luminosity. It was an easy object with a 10×50 binocular, easy to locate even from Rome, under heavily light polluted skies (G. Masi).

Below is an image taken with the PlaneWave 17″ unit, after the average of 5, 10-seconds unfiltered exposures, the star is the brightest object, at the center of the frame:

Nova Del 2013: 15 Aug. 2013

The Celestron C14 robotic unit captured a new spectrum, which is still showing evident emission at H-lpha and H-Beta wavelengths (the latter is apparently a bit weaker than yesterday). The plot is below:

Spectrum of Nova Del 2013: 15 Aug. 2013

– 14 Aug. 2013 –

Possible nova PNVJ20233073+2046041: 14 Aug. 2013

On 14.758 Koichi Itagaki (Yamagata, Japan) reported the discovery of an apparent nova of magnitude 6.8 in Delphinus. A few hours later, we remotely slewed the PlaneWave 17″ robotic unit and confirmed this source, as bright as mag 6.8R, unfiltered. Astrometry follows: 20h 23m 30.68s  +20° 46′ 03.7″ (UCAC4, J2000.0).

Below is a spectrum, taken under less than ideal conditions with the Celestron C14 robotic unit, but showing an evident emission at the H-alpha wavelength. This suggests a classical nova explosion. A nova event comes from the interaction of a dwarf star with its close companion, the former receiving matter from the latter, this finally resulting the cause of the explosion.

PNV J20233073+2046041: a spectrum (14 Aug. 2013)

Later, under much better skies, we captured more spectra and the result is much better: now also the H-beta emission is well visible:

PNVJ20233073+2046041: 14 Aug. 2013

This nova is now close in brightness to the faintest stars visible with the naked eye from a dark place. It is a very easy object with a small pair of  binoculars or a little telescope. If you want to find it, use the star charts below, showing where there is nova Delphini 2013:

Nova Del 2013: wide field star chart

Nova Del 2013: deeper star chart

All these observations were performed by G. Masi, P. Schmeer and F. Nocentini; spectra were reduced with RSpec, while star charts were plotted with TheSkyX.

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