THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
                  49 Bay State Road, Cambridge, MA 02138 USA
                                aavso@aavso.org
                   Tel. 617-354-0484       Fax 617-354-0665

                  AAVSO ALERT NOTICE 346 (February 16, 2007)

SUBJECT: 1651-32 V1280 SCO = NOVA SCORPII 2007

Event: Very Bright Nova in Scorpius

This nova, discovered at 9th magnitude 12 days ago, has brightened dramatically in the past few days to 3rd magnitude, becoming one of the brightest novae in the past several years. It has gained the attention of the professional community and will be observed by numerous satellites, including Chandra, Swift, and INTEGRAL.

Discovered Independently by:
- Yuji Nakamura, Kameyama, Mie, Japan (reported by H. Yamaoka, Kyushu University, IAU Circular 8803);
- Yukio Sakurai, Mito, Ibaraki-ken, Japan (reported by S. Nakano, Sumoto, Japan, IAU Circular 8803)

Discovery Date:
- Nakamura: Feb. 4.8624 UT - Sakurai: Feb. 4.854 UT

Discovery Magnitude:
- Nakamura: 9.9 on two unfiltered CCD images taken with a 135-mm camera lens;
- Sakurai: 9.4 on two 10-s CCD exposures taken with a Fuji FinePix S2 Digital Camera (+ Nikon 180-mm f/2.8 lens)

Position:
Positions have been reported by Nakamura, Sakurai, Nakano, and Kadota. Please use the following position measured by Arne Henden, AAVSO, from photometry obtained at Sonoita Research Observatory:

R.A. = 16h 57m 41.26s, Decl. = -32o 20' 35.6" (epoch 2000.0)

Nakamura reports nothing was detected at his position on images taken Jan. 29.8669 UT (limiting mag 12.0) or Feb. 2.8662 (limiting mag 11.0). Sakurai reports nothing visible on a CCD frame taken on Feb. 2.8 UT.

Spectra: In IAU Circular 8803, H. Naito and S. Narusawa, Nishi-Harima Astronomical Observatory (NHAO), reported that they obtained a low-dispersion spectrum of N Sco 2007 on Feb. 5.87 UT with the 2.0-m NAYUTA telescope (+ MALLS) that suggests the variable is a classical nova caught near maximum light. In IAU Circular 8807, H. Yamaoka, Kyushu University, writes that low-resolution spectroscopy obtained by M. Fujii, Ibara, Okayama, Japan, on Feb. 12.88 and 14.83 UT, and by H. Naito on Feb. 14.86, shows a much bluer continuum than in the spectroscopy taken on Feb. 5.87; the new spectra resemble the spectrum of an F-type star. Balmer lines show clear P-Cyg profiles, along with other weak lines.

AAVSO Chart(s): A chart of V1280 Sco with a sequence bright enough for the current state of the nova is in preparation and will be posted. Currently, it is recommended observers use the following comparison stars provided by Michael Simonsen, Imlay City, MI:

                                 RA (2000)    Dec (2000)
1. SAO 208116 = GSC 7868-1820 16:52:20.144 -38:01:03.13 V(Tycho) 3.56 B-V -0.210
2. SAO 183957 = GSC 6791-2509 15:56:53.076 -29:12:50.66 V(Tycho) 3.86 B-V -0.199
3. SAO 207732 = GSC 7353-3152 16:31:22.933 -34:42:15.72 V(Tycho) 4.23 B-V -0.168

Report Object to the AAVSO as: 1651-32 V1280 SCO

How to Observe: visually or photometrically (V, Rc, or Ic filter)

Observations Reported to the AAVSO:
Feb. 5.818 UT, 8.9 CCD, K. Kadota (via S. Nakano, IAU Circular 8803);
08.3229, 8.0, A. Amorim, Florianopolos, Brazil;
08.7293, 7.9 CCD, T. Scarmato, Calabria, Italy;
08.7301, 7.9 CCDR, Scarmato;
08.7317, 8.0 CCDB, Scarmato;
09.4694, 6.9, L. Shotter, Uniontown, PA;
10.844, 7.5 (K. Kanai, Gunma, Japan, Kanai mags via H. Yamaoka, IAU Circular 8807);
11.4486, 6.9, Shotter;
11.794, 7.0, Kanai;
12.3264, 6.5, Amorim;
12.4757, 6.5, Shotter;
12.790, 6.2, Kanai;
12.86, 6.6, Y. Sakurai, Mito, Ibaraki-ken, Japan; via S. Nakano);
13.2465, 6.0, J. Ripero, Madrid, Spain;
14.782, 5.4, Kanai;
15.4722, 4.9, Shotter;
15.851, 4.5, Kanai;
16.2118, 4.2, W. Kriebel, Schierling/Walkenstetten, Germany;
16.3229, 3.9, Amorim;
16.4583, 3.7, M. Simonsen, Imlay City, MI;
16.2188, 4.1, Ripero;
16.231, 3.8, P. Schmeer, Bischmisheim, Germany;

Notes:
a. Initially announced in AAVSO Special Notice #33 (A. Henden) and Central Bureau Electronic Telegram 834, Daniel W. E. Green, ed.

b. N. N. Samus, Institute of Astronomy, Russian Academy of Sciences, reports that N Cen 07 has been given the name V1280 Sco.

c. For more information, please see IAU Circulars 8803 and 8807, Daniel W. E. Green, ed.

Congratulations to Yuji Nakamura and Yukio Sakurai on their latest discoveries!

Many thanks for your efforts and your astronomical contributions.

Good observing!

Elizabeth O. Waagen
Senior Technical Assistant

SUBMIT OBSERVATIONS TO THE AAVSO

Information on submitting observations to the AAVSO may be found at:

http://www.aavso.org/observing/submit/

If you cannot access this URL, please contact us for submission details. You may also use our charge-free number (888-802-STAR = 888-802-7827) or our fax (617-354-0665) to report your observations.

ALERT NOTICE ARCHIVE AND SUBSCRIPTION INFORMATION

An Alert Notice archive is available at the following URL:
http://www.aavso.org/publications/alerts/

Subscribing and Unsubscribing may be done at the following URL:
http://www.aavso.org/publications/email/