观星手记
认证新彗星ItKa01
Sep 11th
今晚正打算延续前几天2310睡觉计划的光荣传统,正要睡觉,赵晋突然QQ说有颗很亮的新彗星刚被发现~ (哎,离职LUSS之后基本都不看NEOCP了,退化了~)随手一看,是日本人2小时前刚刚发现的,还在等待确认。哎,日本人,勤奋精神真是没说的…… 鹿林正好在台风边缘,天气也勉强可以,就请山上助理看看有没有时间,结果答复说一米镜有时间,哈哈,对着目标区域一阵狂轰,给CBAT写了份报告:
H.-Y. Hsiao and I (Q.-z. Ye) had just taken several 30-second exposured images of ItKa01 by the 1.02-m reflector, located at Lulin Observatory, with Johnson B, V, R filter and clear filter. Seeing is around 1.1". Initial magnitude measurements showed the brightness of ItKa01 is 17.3, 15.3 and 16.1 on B, V and R band respectively. A 70-80" coma was spotted, with a wide, short tail to P.A.~110deg at a length of 1'.
A colored image combined with C, B, V and R band can be seen at http://yeiht.y234.cn/wordpress/?p=717.
ItKa01 C2008 09 10.68495 20 39 27.18 -01 20 29.5 17.3 D35
ItKa01 C2008 09 10.68581 20 39 27.26 -01 20 31.5 15.3 V D35
ItKa01 C2008 09 10.68667 20 39 27.29 -01 20 31.9 16.3 R D35
ItKa01 C2008 09 10.68966 20 39 27.55 -01 20 36.7 16.1 R D35
ItKa01 C2008 09 10.69062 20 39 27.60 -01 20 37.5 15.9 R D35
这个彗星挺彗星样的,没劲儿,一米镜发挥不出什么优势来。回头一看,貌似是中野主一已经用东京天文台的1米也追到了这个目标,彗星无疑了。初步的轨道显示是个短周期?不知道是不是,哎,大约让日本人钓到大鱼了…… 把三个通道叠加了一下,照片也贴在这里给大家玩赏玩赏吧。
OK,这一个lunar period的任务结束,收工,过中秋~~~ 提前祝各位中秋节快乐~~~
祝贺新疆星明天文台发现陈-高彗星C/2008 C1!
Feb 3rd
中国人发现的第9颗新彗星—— 祝贺陈韬、高兴和赵晋团队!遗憾的是根据初步计算,彗星最亮仅为11等而且观测条件十分不好。但无论如何,这都是中国天文界的大事!深表祝贺!
[[Image:Other/080203a.jpg|550|陈-高彗星,德国Irmtraut天文台J. J. Mueller摄于2.97日(UT)]]
Tuttle和McNaught的颜色
Jan 12th
1月11日想在两颗彗星上捞点胜利者的滋味,结果全部吃了个闭门羹。
当晚我发现天气很好,恰巧Q群上的人又在讨论Tuttle彗星,说它现在已经增亮到5.9等。前段时间七擒Holmes还是让我感到颇为得意,于是我拿出大双筒决定要把它收归麾下。
在女生宿舍对面拿出望远镜有可能和在黑熊面前拿出肉饼是等价事件,不过经我多次实践证明这一可能性不成立的概率至少等于1个σ也就是84.13%。总之我便光明正大地把望远镜架好,然后打开电子星图来慢慢搜寻。
可厌的是Tuttle彗星恰好处于秋季星空中星比较少的位置,加上大学城的光害并不很轻,因此我艰难地在星海中寻找定标,一边找一边想起某位天文学家的高见:We are actually spy on the stars(其实我们是在偷窥星星);用望远镜看女生宿舍和看星,本质上都是—— 偷窥,只不过一个是平视,一个必须仰视。胡思乱想了一阵,竟然找到了鲸鱼座ζ—— 距离Tuttle彗星最近的一颗亮星,顿时一阵兴奋,于是按图索骥,很快找到了Tuttle彗星的预报位置。
按照预测,Tuttle彗星在TYC 5283-1309-1和TYC 5283-1016-1附近,其中后者是颗7.4等星,照例来说一个5.9等的目标应该很容易看到,但我看来看去就是看不见。哎,可怜的Tuttle老先生,奋斗一生,死去的时候仅有70美刀,还要被“埋在一个不知名的墓穴里”,现在连他的彗星也不愿意和他同名来让我瞻仰瞻仰。于是我用了深呼吸+侧视法,又隐约撇到彗星西面一点点的两颗8.3等星,但还是看不到。看来彗星太弥散了,加上一点光害就看不见。我正想再尝试一下,结果发现星星突然暗了下去,抬头一看,原来起云了。
我悻悻然收拾装备,却发现T3项目的PI、那个意大利人用半通不通的英文发来一封邮件,原来是说澳大利亚的McNaught发现了一颗15.5等的新目标,从路径上来看很像是彗星,提醒注意。我一看,鹿林天气正佳,决定从这个目标上捞回一些自信。23点以后是我的观测时间,于是我指令望远镜拍了三张那个新目标的照片,之后把数据传输过来分析。
一打开照片,我叫苦不迭:怎么恰巧那个彗星走到了一颗亮星的附近呢!这下可好,本来地平高度就很低,给那个亮星一折腾,几乎什么都看不出来了。我只好给国际天文联合会写信说FWHM slightly larger than background stars,想着到时候公布新发现的时候我这模棱两可的报文大约也能分一杯羹。给McNaught彗星一搞,我十二点半才晕头晕脑的爬上床,2310计划(23:10上床)又告失败。
第二天一早起来,床还没有下,就用手机上网看新消息,果然McNaught彗星的发现已经正式公布了,编号C/2008 A1,而且年底还可以到9等。我一口气看到底,怎么纬度比我高的几个老美都看到了彗星特征了?至于我的报告自然是没用上。啊,完全是“彗星‘恰巧’和一颗大亮星来个亲密邂逅”的背运!我恼怒地把被子往旁边一丢,无精打采地跳下床来。
[[Image:Lulin-Sky-Survey/ck08a010_20080112.png|550|C/2008 A1 (McNaught)]]
双子座流星雨观测札记
Dec 18th
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
Oct 1st
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
Aug 29th
[[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
Aug 28th
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
Jul 14th
[[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!"
Jul 1st
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.
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