Telescope Reviews: Binocular Icon 45 : NGC 1499 in Perseus.

NGC 1499, the California Nebula.

When we look in the direction of the constellation Perseus, we actually look towards the edge of our galaxy. Because the outer spiral arms are less star-rich than the central region, the Milky Way appears much dimmer in the direction of the winter constellations. Nevertheless, Perseus has some interesting deep-sky targets to offer. One of them is the very elusive California Nebula, NGC 1499. But our journey starts at 3rd magnitude Zeta Persei. Zeta Persei is the lucida of the very young stellar association Perseus OB2. Perseus OB2 is a member of Gould’s Belt, and thus relatively nearby. At a distance of 1200 l-y, Perseus OB2 is only one million years old. Among its members are Zeta, Omicron, Xi and 40 Persei. All these young stars are born in the same cloud of dust and gas. It appears that the giant star Xi Persei has become a runaway star. Xi Persei seems to have left the centre of the association with a relative high speed, and it has travelled about 200 l-y, away from Perseus OB2. On its path through the galaxy, Xi Persei has neared the California Nebula. In fact, the nebula as we see it, is illuminated by Xi’s strong ultraviolet radiation. The California Nebula is about 1300 l-y away and measures 160x40 l-y.
For the visual observer, NGC 1499 is a challenging target. While the object measures 2,5° x 1°, it has a very low surface brightness. Therefore dark skies are mandatory, together with enough field of view to see the nebula against. Low power instruments, like 10x50 bino’s up to rich field telescopes, if possible equipped with nebula filters, are preferable.
I tried to observe the nebula when it was near zenith, with my 15x70 bino’s, but without any filters. Think faint, think elusive. It takes time for the eyes to detect the subtle glow of this large nebula. The northern part of the nebula appears to be the broadest and the brightest region of the nebula. The southern part is hard to discern. Both parts appear to merge at the W side of the nebula, while at the E side, they look separated until at the very eastern tip of the nebula.
I decided to draw the nebula not too bright. Therefore you will not see it clearly on your monitor if your room is not dark enough. The bright star S of the center of the sketch is Xi Persei.

Site : Le Castellard Melan, France ( 44° N )
Date : September 29, 2008
Time : around 23.30UT
Binoculars : TS Marine 15x70
FOV: 4.4°
Filter : none
Mount : Trico Machine Sky Window
Seeing : 2/5
Transp. : 4/5
Sky brightness : 21.35 magnitudes per square arc second near zenith (SQM reading).
Nelm: 6.4
Sketch Orientation: N up, W right.
Digital sketch made with Corel Paint Shop Pro X2, based on a raw pencil sketch.

(Note: if the sketch does look too dark on your monitor, try to darken the room.)

--------------------
Rony

My Astronomical Sketches

My Binocular Sketches

Callibrate your Monitor with this little strip.

Edited by rodelaet (11/05/08 05:04 PM)