Nova Scorpii 2007 No 2 (V1281 Sco)
While Nova V1280 Sco is still a naked-eye object in the Scorpion, a second nova has erupted a mere 3° to the south. IAU Circular 8810 announced the new star, V1281 Sco, yesterday. It was discovered by Yuji Nakamura, who is also the discoverer of V1280! The nova was independently discovered by Hideo Nishimura. Both astronomers reported the star as being around V=9.2.
A CCD image obtained by K. Itagaki (Yamagata, Japan) on February 20.85 identified a new 8.8 mag star at RA 16h 56m 59.35s, Dec. -35° 21' 50.2".
The finder chart below, based on an image taken on Monday morning (19th) shows its proximity to V1280.
I was thrilled this morning when yesterday's cold front had moved past, leaving the skies wonderfully clear. Keen on seeing two novae so close together, I wasn't disappointed, as the photo below shows.
The close-up below shows the new star, certainly brighter than 10th magnitude and thus an easy binocular target. In the absence of a suitable AAVSO chart, I've used V magnitudes converted from TYCHO to estimate it at V=9.2.
Soon after writing this, I learnt the AAVSO has issued an alert about this nova.
Wouldn't it be great if this star would brighten quickly enough so that both it and V1280 would be naked-eye at the same time! Let's hold thumbs.
The Central Bureau for Astronomical Telegrams announced on IAUC 8812 (Feb 22) that a spectrum taken on Feb 21.84 at the Nishi-Harima Astronomical Observatory in Japan confirmed that V1281 is a classical nova. The spectrum also shows evidence of "considerable interstellar reddening", which suggests that this nova is not likely to become as bright as V1280... :(
The skies were mostly clear this morning when I ventured out at 05:10. However, the fleecy tendrils in the north and west, though innocent looking, created a thin haze that defeated my attempts to photograph V1281. Where I could usually image down to 11th magnitude, this morning I barely achieved 9th, as the image shows:
Down to this limit, though, nova Sco 2007 No 2 was not visible. So I've logged it as "fainter than 9.0" – disappointing because I was hoping it would brighten to naked-eye glory. Sigh.
At last – V1281 registered as a few pixels on a 15sec image. Again with the cloud, however.
With certainty, it is fainter than V=9.6 (HD 152740), but I think it's actually a bit beyond that (< 10.0); I couldn't pick it up in 11x80 binoculars.
I couldn't log it at the AAVSO, kept getting a "Show error... Error 1040 : Too many connections in" message this morning, so I have no idea what other observations have been reported since yesterday.
Got a good image this morning, as the twenty-image sandwich below shows. Using V magnitudes transformed from TYCHO B & V magnitudes, the nova is about V=10.7 now.
The light curve below, compiled from IAU Circular and AAVSO data, shows the steady decline in brightness.
Feb 23 @05:25, Feb 23 @13:31, Feb 27 @ 05:57, Feb 28 @ 07:21.
nothing more to see. please move along.