L4彗星CMOS测光结果

许文韬使用本人于4月13日凌晨拍摄的图像，对C/2011 L4 (PanSTARRS)彗星进行了CMOS测光分析，因平场与暗场的拍摄失误，以及彗发中含有数颗背景恒星，使得测光难以进行，在尽量消除各种影响之后，最终测得彗星总星等为5.83等，误差0.01星等，系拟合标准差获得。




Place:           Qixingtai, Jinan, Shandong Province, China
Timestamp:  2013/04/12 19:51 UTC - 20:49 UTC
Optics:         Canon 300mm f/4 L IS USM, set to 300 mm f/5
Camera:       unmodified Canon EOS 5D Mark II (ISO 1600)
Mount:         NEQ6 Pro
Exposure:    45 frames x 1-min
Processing:
images stacked in IRIS 5.59 with standard calibration procedure performed; fixed with Fitswork V4.44 and Photoshop CS3 Extended; 0.5x resized and cropped;
Comments:
The images were taken by Pui-Yuen Suen and processed by me. Transparency was poor with some haze. It was strongly windy as well. All of the images were influenced by brightening morning twilight more or less.
Mouseovering the image was a combination from sigma clipping method, 5 iterations, otherwise from median method. The saturation of the coma was also enhanced in the former.


The images were taken by Pui-Yuen Suen and processed by me. Only photometric work has been performed with the observation. The calibrated images were stacked into a final one by means of median algorithm. The colored image was splitted into three channels, i.e. R, G, and B. It was channel G that was utilized in the photometric work. The catalog used is Johnson V band in CMC-14.

Radius of aperture  0 = 10.0
Radius of aperture  1 = 15.0
Radius of aperture  2 = 20.0
Radius of aperture  3 = 25.0
Radius of aperture  4 = 30.0
Radius of aperture  5 = 35.0
Radius of aperture  6 = 40.0
Radius of aperture  7 = 45.0
Radius of aperture  8 = 50.0
Radius of aperture  9 = 55.0
Radius of aperture 10 = 60.0
Radius of aperture 11 = 65.0

Inner radius for sky annulus = 120.
Outer radius for sky annulus = 150.

Sky   SkySig    SkySkw   Magnitudes
573.65   20.30    0.34    7.401+-0.002    7.064+-0.002    6.854+-0.002    6.708+-0.002    6.595+-0.002    6.498+-0.002
                                      6.417+-0.002    6.351+-0.002    6.293+-0.003    6.243+-0.003    6.195+-0.003    6.155+-0.003

ZP = 21.396

I employed an IDL routine written by myself to obtain the infinite aperture magnitude, which yielded m=5.833±0.007.



http://tech.dir.groups.yahoo.com/group/CometObs/message/5136

http://comethunter.lamost.org/sc ... 11L040.htm#20130412

http://comethunter.lamost.org/as ... 11L040.htm#20130413

http://spaceweather.com/gallery/indiv_upload.php?upload_id=80818

不错的资料！

若无记错，此应是国内首个天文爱好者的L4彗星CMOS测光报告。

好~~
顶了！

精准！
贊頂~

资料很好

专业的人才啊。大帅见了必提一帆风顺。

多谢分享

好资料！加油！

看不懂。不过貌似很厉害的样子！！！

我也看不懂，但表示支持