Friday, October 14, 2005

Astronomical Almanacs for SALCs

The following charts graphically show when a section of the sky is above a certain altitude (i.e. 30 & 50 degrees above either horizon). The thick black line shows when the area is transiting the meridian. SALCs are Search Area Location Charts sectioning off areas of the Milky Way used for nova hunting.

Overlaying the three twilights will clearly show when the area is visible in the evening after astronomical twilight and before Central Park closes at 1:00 AM.

The pink upright lines represent the beginning of at least 1 hour of viewing time before the park closes or when the area is between 30° & 50° shortly after astronomical twilight. This is considered a 'season' and exists both when the area is rising and when it is setting.

[Image] SALC 89 in Aquila
Seasons for this region:
• Rising: Jun. 1st (midnight) - Jul. 13th (10:27p)
• Setting: Aug. 15th (midnight) - Nov. 15th (6:12p)

[Image] SALC 34 (north) in Perseus
Seasons for this region:
• Rising: Aug. 30th (midnight) - Nov. 28th (6:07p)
• Setting: Jan. 6th (midnight) - Mar. 26th (7:47p)

[Image] SALC 53 in Auriga
Seasons for this region:
• Rising: Oct. 9th (midnight) - Dec. 29th (6:15p)
• Setting: Feb. 1st (midnight) - Apr. 10th (9:10p)

[Image] SALC 93 in Monoceros
Seasons for this region:
• Rising: Nov. 6th (midnight) - Feb. 10th (6:54p)
• Setting: Jan. 20th (midnight) - Apr. 9th (9:04p)
• Daily double: Jan. 20th (midnight) - Feb. 10th (6:54p)

(In order to view the chart properly you may need to hover the cursor over lower right corner of the image to 'Expand to regular size')


Tag said...

Hi Ben,

This effort is coming along nicely. After reading the neighboring, recent report first, now I realize why your coming out later in the evening. SALC 53 is rising to season a bit after 11pm;
Monoceros not available to mid-November.

Are these centered on the SALC area or a specific star within the search area?

Keep it up.


Ben C. said...


The SALCs are plotted using the exact center of the SALC. It becomes very clear where the seasonal gaps are and where they should be filled in.

Yesterday I added a new SALC near Mirfak in Perseus which should get me out earlier.

I will split the official SALC into two so I can fit it on one piece of paper. The charts get very crowded when you print out stars to mag 9.0 and dimmer.

See you soon.