V5584 Sgr = Nova Sgr 2009 No. 4

Following posting on the Central Bureau’s unconfirmed-objects webpage, P.Corelli (Pagnacco, Italy) writes that his 10-s CCD frame taken on Oct. 26.764 with a 0.45-m f/4.4 reflector yields mag 9.3 and position end figures 32s.79, 07″.8; he adds that nothing is visible at this position on a Palomar plate (limiting mag 21.0).
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This bright nova should be observed daily, and observations sent to AAVSO. Please seehttp://www.aavso.org/publications/specialnotice/173.shtml on reporting requirements.

Mati Morel has kindly supplied the following (revised) comparison sequence, and a chart:
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This is a very crowded field, and it needs careful examination of a DSS print to pick out good comparison stars. This has been done, and a couple of changes made. Star 9 has been deleted, due to apparent crowding, and two new stars inserted, 8A and 8B. The revised sequence is reproduced below. The sequence should suffice till BV data becomes available. A chart showing the field has been uploaded to the VSS files section; go to www.google.com/group/vss-members/files
and look for a chart named N_Sgr_2009#4_e.
I have previously indicated my intention to do so, and by keeping the file size small it shouldn’t take up much disk space.

Star no. RA2000 Dec2000 V V_err B-V B-V_err S Name
====================================================
1. 18 32 18.66 -16 06 10.9 9.381 0.031 0.314 0.031 T2 HD 170884
2. 18 31 49.00 -16 07 11.1 9.716 0.041 0.346 0.043 T2 HD 170762
3. 18 32 00.48 -16 18 40.8 10.514 0.017 0.225 0.070 A+T2
4. 18 31 42.27 -16 32 24.6 11.100 0.025 0.173 0.116 A+T2
5. 18 31 08.95 -16 31 09.8 11.305 0.034 NA NA A
6. 18 31 10.46 -16 25 52.8 11.639 0.036 NA NA A
7. 18 31 48.77 -16 19 33.3 11.855 0.040 NA NA A
8. 18 31 17.36 -16 16 56.7 12.105 0.064 NA NA A
8A. 18 31 29.40 -16 22 24.7 13.006 0.107 NA NA A
8B. 18 31 41.45 -16 17 31.5 13.817 0.180 NA NA A
10. 18 31 37.59 -16 18 36.2 13.925 0.159 NA NA A

Codes:
A = ASAS-3 T2 = Tycho-2

By the way, the AAVSO no longer employs the Harvard Designation number (the six-digit number which generally preceded the name of the variable), so we may as well follow, unless someone can provide a good reason for hanging on to it. In future I will tend not to use it.
Regards,
Mati Morel
Variable Stars South

[email protected]

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