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         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 347 (February 22, 2007)

SUBJECT: 1650-35 V1281 SCO = NOVA SCORPII 2007 NO. 2

Event: Nova in Scorpius

Discovered Independently by:
- Yuji Nakamura, Kameyama, Mie, Japan, (via H. Yamaoka, Kyushu University, IAU Circular No. 8810)
- Hideo Nishimura, Miyawaki, Kakegawa, Japan, (via S. Nakano, Sumoto, Japan, IAU Circular No. 8810)

Discovery Date:
- Nakamura: Feb. 19.8593 UT
- Nishimura: Feb. 20.8365 UT

Discovery Magnitude:
- Nakamura: 9.3 on two unfiltered CCD images (135-mm camera lens);
- Nishimura: 9.2 photographic (T-Max 400 film, Pentax 6x7 camera)

Position (provided by K. Itagaki, Yamagata, Japan):
R.A.= 16h 56m 59.35s, Decl. = -35o 21' 50.2" (2000.0)

Spectra:
H. Naito and S. Narusawa, Nishi-Harima Astronomical Observatory (NHAO), and H. Yamaoka, Kyushu University, report that a low-resolution spectrogram taken on Feb. 21.84 UT with the 2.0-m NAYUTA telescope (+ MALLS) indicates that the star is a classical nova. They also report that a narrow Na I D absorption feature suggests the existence of considerable interstellar reddening.

AAVSO Charts:
The comparison stars listed below are among those used by Sebastian Otero in his sequences and have been checked in ASAS and GCPD by Michael Simonsen, Imlay City, MI, and are recommended for use at this time. According to Simonsen, red stars among Otero's stars have been excluded here.

Comp       VMag   Verr     RA (2000)    Dec (2000)
84        8.43    0.03    16:57:56.0    -35:44:20
89        8.91    0.03    16:56:18.3    -35:28:58
91        9.06    0.03    16:58:24.2    -34:35:23
94        9.35    0.05    16:53:26.7    -35:27:32
97        9.70    0.02    16:55:56.8    -35:55:31
102       10.22   0.08    16:55:52.5    -35:03:50
106       10.57   0.08    16:58:41.8    -35:23:30
110       10.97   0.06    16:58:30.5    -34:58:38
114       11.36   0.05    16:55:01.4    -35:26:29
120       11.97   0.05    16:57:12.9    -35:16:40
121       12.11   0.03    16:56:51.1    -35:13:30
126       12.62   0.08    16:56:24.8    -35:20:12

These stars down through the 106 are currently available (the rest will be available tonight) via the Variable Star Plotter at this URL:

http://www.aavso.org/observing/charts/vsp/

On this page, enter "N SCO 07#2" ("V1281 SCO" should work later tonight) as the name. The comp stars will all fit on a 120' plot. If you prefer to go directly to a 120' south-up chart with these stars, there is one at

http://tinyurl.com/23thvm

Report Object to the AAVSO as: 1650-35 V1281 SCO

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

Observations Reported to the AAVSO:
Feb. 14.8575 UT, <12.0 CCD, Nakamura;
15.8 <11.0 photographic (T-Max 400 film), Nishimura;
19.8593, 9.3 CCD, Nakamura;
20.8365, 9.2 photographic, Nishimura;
20.8370, 9.2 photographic, Nishimura;
20.85, 8.8 CCD, Itagaki

Notes:
a. Initially announced in IAU Circular 8810, Daniel W. E. Green, ed., and AAVSO Special Notice #34 (E. Waagen).
b. N. N. Samus, Institute of Astronomy, Russian Academy of Sciences, reports that N Sco 07#2 has been given the name V1281 Sco.
c. Yamaoka's report includes that the new object is within 30" of the red star GSC 7367.712 (R.A. = 16h 56m 58.0s, Decl. = -35o 21' 39", equinox 2000.0, mag 13.3; variable according to ASAS).
d. For more information, please see IAU Circular 8810 and Central Bureau Electronic Telegram 855, Daniel W. E. Green, ed.

Congratulations to Yuji Nakamura and Hideo Nishimura on their latest discoveries!

Many thanks for your efforts and your astronomical contributions.

Good observing!

Elizabeth O. Waagen
Senior Technical Assistant

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