观星手记

双子座流星雨观测札记

  第5次观测双子座流星雨,并没有给我留下什么深刻印象,也随便写两句吧。
  13/14日本来打算做一个峰值前的观测,整晚的好天气,居然正要观测的时候起云了,于是找到了一个好理由去睡觉。
  14/15日摇摆了整整一天,要不要和星会去高明高村,最后周恒说给我蹭他的车去,还是决定去了。天气是难以置信地差—— 比大学城最好的时候还糟糕(god,可是开了两个多小时车到的),主要是太大雾了。晚上天气时好时坏,不过耐心等待总能收到回报—— 整晚数到93颗流星,上报的报表含71颗。今年的双子座流星雨亮流星不太多,而且对我们来说最亮的流星总是出现在云雾遮蔽的时候,欣赏程度上大打折扣。1点半以后天气一直不佳,不过能看到总得来说还是值得庆贺的。
  15/16日,尽管连续两天缺少睡眠,我还是坚持上楼顶做了40分钟的检测。城市的天空如果遇上大雾,看起来简直就和被人用红布蒙了脑袋差不多—— 只看到火星和天狼星在红彤彤的天空中可怜巴巴的亮着(当然,适应一下还是可以看到不少星),40分钟下来竟然能看到5颗,也实在是奇迹了。16/17日雾散了不少(从来如此:最重要的时刻总有些碍事的东西要出来凑热闹,过了那个时间它们才开溜),不过23点的时候起云了,总算避免我继续自我摧残。

客串一回专业天文学家

  仔细研读了说明之后,我也客串了一回在天文台里控制望远镜使用的专业天文学家!哈哈。9月28日早晨3点多爬起来,接过鹿林方面的控制权,遥控望远镜进行观测。那天晚上一共观测了8个等待确认的近地小行星和1颗新彗星。
  顺便啰嗦一句:电信的速度实在不行,晚上到鹿林的带宽只有不足100kbps,搞到我要凌晨起来才能观测!不满……

[[Image:Other/20071001q.jpg|550|我正遥控鹿林的望远镜进行近地小行星追踪工作]]

失败的月食之夜

[[Image:Other/20070828a.jpg|550|8月28日月全食生光时分,全天只剩下月球所在的一小片天区还是乌云密布,甚至这块乌云上面已经是星光闪烁。尽管我甚至能清楚地看到月亮照在云上那银色的光芒,但直到复圆时刻,月亮都未能挣脱乌云的束缚。我未能继2001年1月以后再次成功观测到月全食。]]

PS: 贴出来真是有点晕菜。原图上乌云后面繁星点点,煞是美丽,这里差不多90%压缩以后基本上都没掉了,大家得点击进入才能欣赏原图罗!(嘻,卖广告……)

日月食观测成败录

  序:叶某人的日月食观测史,就像是一部从好运到背运的退化史,且待分解:

  • 1997年3月9日 日偏食
      第一次观测日食,晴空万里,完全成功。
  • 1997年9月17日 月全食
      第一次观测月食,恰好是中秋节,也是晴空万里,完全成功。
  • 1998年8月22日 日偏食
      晴间少云,也是很成功。
  • 1999年1月31日 月半影食
      食分很大的月半影食,接近偏食,晴间少云,第一次拍到月食照片。
  • 1999年7月28日 月偏食
      海上观测带食月出,天气晴朗,观测成功。
  • 2000年7月16日 月全食
      天气晴朗,观测成功。
  • 2001年1月10日 月全食
      天气晴朗,观测成功。

转折点从此开始……

  • 2001年7月5日 月偏食
      开始晴朗,食甚以后转阴。好歹还是观测了大半。
  • 2002年6月11日 日偏食
      阴天有降雨,但还是坚持出去观测,好歹观测到几十分钟,之后又转阴下雨。
  • 2004年5月5日 月全食
      整晚天晴,但是…… 初亏的时候开始阴天,食甚的时候开始下雨,复圆之后天气恢复晴朗,堪称最背运的一次月食观测。
  • 2005年10月17日 月偏食
      多云间阴,勉强观测了一分钟不到,但复圆以后天气转晴。
  • 2006年9月8日 月偏食
      全晚阴天,没看到。
  • 2007年3月4日 月全食
      下雨。
  • 2007年3月19日 日偏食
      运气还算比较好,夜间下雨,日食开始以后渐转多云,看到了大半。
  • 2007年8月28日 月全食
      少云,云恰好在月亮那一带,观测场地成为珠三角唯一一处全程看不到月食的地方。月食结束以后一小时,月亮出现。

  今天大好天气,搭了一个钟头地铁跑到大学城,结果全广州都看到了月食,家附近还全程可见,就我半秒钟都看不到,大为郁闷,感慨乎:以前一到日月食,坏天气也变好;现在一到日月食,好天气也变坏!于是整理了一份表,发现其实还是看到日月食居多,只不过最近连续几次月食都看不到,产生了某些心理效应…… 郁闷之情遂解。
  顺便列出下几次广州可见的日月食时间,以供参考:
2008年8月1日 日偏食 食分83% [带食日落]
2008年8月17日 月偏食 食分81% [带食月落][下半夜]
2009年1月26日 日偏食 食分35% [带食日落]
2009年2月9日 月半影食 食分92% [上半夜]
2009年7月22日 日偏食 食分78%
2010年1月1日 月偏食 食分8% [下半夜]
2010年1月15日 日偏食 食分70%
2010年6月26日 月偏食 食分54% [带食月出][上半夜]
2010年12月21日 月全食 食分126% [带食月出][上半夜]
2011年6月16日 月全食 食分171% [带食月落][下半夜]
2011年12月10日 月全食 食分111% [上半夜]
2012年5月21日 日环食 食分96%
2012年6月4日 月偏食 食分38% [带食月出][上半夜]
2012年11月28日 月半影食 食分94% [上半夜]

2007 NL1: All luck but luck

[[Image: Lulin-Sky-Survey/k07n01l_20070711.png|500|2007 NL1 at discovery.]] 

I rarely write blog in English but today due to some reasons I'll do it, the reason is quite unusual: an asteroid, but the asteroid is quite unusual too, it's a Near-Earth Asteroid. That boy, 2007 NL1, became the first NEA I have got.

Long long stories of discovery could be reduced to a sentence: I scan, I spot, I found. I won't repeat this routine but will just mention two interesting spots during the discovery.

Spot 1: To be or not to be...

It seems pretty fine for me that all big surveys are off from work this dark run, but I just didn't get lucky. Our survey detected five NEOs in three nights -- a new record ever, but all of them are known -- include those very promising R~20's! Lord. So when I saw another detection on afternoon of July 12, all I thought was: "another known one, dot."

But usual checks went on.

"So that boy is a new one?" Out of the expectation and within the expectation, I asked myself. Well, possibly something simply went wrong. I had been chased those "NEOs" three or four times, stayed up for several nights, and later they turned out to be a-little-unusual main-belts. But a thing moving at 1.5 degree per day can't be anything. I checked again.

Indeed something went wrong, I had examed a wrong one. *That* boy called YQ00uR, not YQ00uS. I have to check for knowns again. But still no known ones turn out.

My heart was beating fast. The "one" finally comes.

Spot 2: Big surveys, where are you?

I never thought I'll miss the big surveys, I always regard them as big rivals, but on July 13 I found myself missing them!

YQ00uR was running quickly in the sky and the uncertainty area kept growing. July 12/13 nights were cloudy and I could do nothing but writing "help needed" mails. All surveys were off for holiday due to monsoon season on southwest United States except Siding Spring Survey in Australia, so it seems Siding Spring is my only option. Dr.McNaught replied my mail very quickly, and the answer was simple: cloudy. Then I look for other helps: Peter Birtwhistle at United Kingdom, Reiner Stoss at Spain, Jean-Claude Pelle at Tahiti Island, and they were all not okay with the rock.

Well, real problems occured. Seems I have to do anything to secure the rock on July 13/14 by myself. I spent a whole afternoon for observing design, then went to bed on around 7 p.m. On the morning of July 14 I have to cover dozens of arc degrees to catch the boy.

I dreamt I was searching for a little rabbit in a big big forest.

On 1 a.m. I got up. Jean-Claude told me the sky became clear at Tahiti and he was hunting. "I'd better secure the boy myself." I thought, then I began. There were 16 fields, coded Field 1 to Field 16. It would take 2 hours to fix, and they covered all the uncertainty area. "It won't lost..." I encouraged myself, "I still have one extra hour if all these 16 attempts are failed." Then I download image sets of Field 1, they were just finished.

Guess what happened? A faint, fast moving dot at the center of the images! I combined it with the observations on July 11 -- very fit! It's a nice Apollo.

I can't believe my eyes. The boy was done in such an easy way! I could just said I have been lucky.

I got up at 10 a.m. and the sun was high in the sky, the rock -- 2007 NL1, has been published in Minor Planet Electronic Circular. I also learned Jean-Claude had spot the asteroid too, a few hours earlier than me, but he reported it later than I did.

And so the big surveys are big rivals again ;-)

Astronomy Tale: "Ah Nuts!"

On one starry night at Kitt Peak, the Advanced Observing Program was well underway. After setting the camera up to begin imaging our first object, I instructed the telescope to slew towards its final destination. After a few moments I heard sounds which elicit dread in the hearts of telescope operators everywhere. The strange noises began with a soft “bink clink clink clink” and ended with mysterious “somethings” falling to the floor with a definitive “plit plot!” Not wanting to look concerned in front of the paying customer; I silently held my breath and illuminated the floor with a flashlight. I fully expected to see small sprockets and gears glistening beneath my feet- but no hardware was there! I did find something though. Scattered on the floor were small acorns and I had no idea from whence they came! In disbelief I randomly moved the telescope in Right Ascension and, sure enough, more acorns fell to the floor. Inside the hollow of the east fork arm I found a collection of a dozen acorns. Moments later, after cleaning out the stash, a small mouse skittered up the pier and came to stop between my feet. For one brief moment we stared at each other and telepathically the mouse seemed to say with a sneer “Thanks a lot buddy!” Then the bold creature ran out of the observatory, never to be seen again.

-- Adam Block, http://mstecker.com/pages/appblock.htm.