＊　小惑星4ベスタがしし座ガンマ星に接近　＊





Vesta is now a prime binocular target. This week it's near opposition, shining at magnitude 6.1, and on Tuesday the 16th it threads the gap between Gamma and 40 Leonis.


四大小惑星のひとつベスタが、2月21日にしし座で衝となる。ししの大鎌のあたり、2等星アルギエバのすぐ近くにあるので、位置の見当をつけるのは簡単だ。明るさは6.1等で、双眼鏡があればすぐに見つけられるだろう。日をあけて観察すれば移動しているようすがわかり、恒星ではなく小惑星であると確認できる。






−−　SkyandTelescope　2010年2月 アストロアーツ　−−

　＊　小惑星433エロスが2012/01/31に地球最接近　＊





A Rare Flyby of Asteroid Eros




The first near-Earth asteroid to be discovered was 433 Eros in 1898. It made history then, in part by enabling the best determination of the astronomical unit and hence the scale of the solar system.



Asteroid 433 Eros


The NEAR-Shoemaker spacecraft recorded this view of asteroid 433 Eros on February 12, 2000.


NASA / JPL / JHU-APL


It made history again in 2000 and 2001, when NASA’s NEAR-Shoemaker probe took up orbit around it and then descended to its dusty surface. Eros is the second-largest near-Earth asteroid, after 1036 Ganymed, measuring 21 × 7 × 7 miles (34 × 11 × 11 km).



And now you have an opportunity to view this celebrated object telescopically, as it makes a swing past the Earth this month and next. This is Eros’s closest approach since the much-observed one in January 1975, when it reached magnitude 7.0, and it'll be its last close pass until January 2056.


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Asteroid Eros finder chart


Click above to download detailed printable finder charts for asteroid Eros in PDF format.


Sky & Telescope diagram
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Click here to download finder charts showing its path southward across Leo, Sextans, and Hydra as it brightens from magnitude 9.2 on January 12th to 8.8 on the 18th and then 8.6 from January 25th to February 13th. It fades back to 9.0 by February 25th. Eros passes its closest to Earth on January 31st, but even then it’s not very close as near-Earth asteroids go: 0.18 a.u., or 70 times the Moon’s distance.



On the charts, the ticks mark its position at 0:00 Universal Time on the indicated dates. This falls on the evening of the previous date in the time zones of the Americas. Interpolate to put a pencil dot on the track for when you plan to look. Stars are plotted to magnitude 9.0. In late January and early February Eros will be creeping along by almost 3′ per hour, so you can see its motion during an evening.



Updates:



. Amateurs and students can use position measurements of Eros to (re)compute the length of the astronomical unit. Read more and join the project .



. From Italy, Gianluca Masi at Bellatrix Observatory writes, "at the Virtual Telescope we will offer a live online observing session" of Eros's passage, in exchange for a 1-euro donation, starting at 0:00 February 2nd UT.



Posted by Alan MacRobert, January 13, 2012

　＊　小惑星1036ガニメトが2011/10/29地球に最接近　＊





1036 Ganymed is the largest Amor asteroid, at about 32 km in diameter.[3] It was discovered by Walter Baade on October 23, 1924, and is named after Ganymede, the Trojan prince turned god whom Zeus designated the cupbearer to the Greek gods (Jupiter's moon Ganymede is also named after that individual). It is also a Mars-crosser asteroid.




Owing to its early discovery date, Ganymed has a rich observational history. A 1931 paper published the absolute magnitude, based on observations to date, as 9.24,[6] slightly brighter than the present value of 9.45. Ganymed is an S-type asteroid, meaning that it is relatively reflective and composed of iron- and magnesium-silicates. Spectral measurements put Ganymed in the S (VI) spectral subtype, indicating a surface rich in orthopyroxenes, and possibly metals (although if metals are present they are covered and not readily apparent in the spectra).[3]




天文年鑑2011版169頁によると、
10月28日頃、最近120年間（1900−2024年）のうちではもっとも明るい8.3等までなる。


年月日 2011/10/28（9hJST）


赤経2h06.02m　赤緯+15d17.9m


等級（V）8.3m


太陽離角 178度

　＊　小惑星4450パンが地球に接近　＊





4450 Pan is an asteroid that was discovered on September 25, 1987 by Eugene and Carolyn Shoemaker. It is a Venus, Mars, and Earth crosser. Pan approaches nearer than 10 Gm to those three planets, and within 20 Gm of Mercury.





The 1.6 km wide Apollo asteroid 4450 Pan (1987 SY) will make a  flyby of the Earth  on February 19th 2008, at a distance  of 15.9 lunar distances (0.0408 AU)


The asteroid will appear as a magnitude 13 star in the constellation Lepus, and be viewable in 8" telescopes.


The asteroid was discovered  on 25th September 1987,  by C. Shoemaker at the  Palomar  observatory.

　＊　地球接近小惑星　わずか約423万キロメートル　＊




2005 WJ56 was discovered by LINEAR on November 29, 2005.  

It will approach within 0.0279 AU (10.9 lunar distances) on January 10 when it

will be a very strong radar target.  Goldstone observations are scheduled 

on January 13 and Arecibo observations are scheduled on January 9-11.



Note that Goldstone observations straddle the January 12-13 date boundary;

we can start setting up late on Jan. 12 and begin transmitting at 01:15Z 

on Jan. 13 (5:15 PM, Saturday, January 12, Pacific Time).


Given its absolute magnitude of 17.8, 2005 WJ56 has a diameter that is probably 

within a factor of two of 870 meters.  Otherwise, we know nothing about its 

physical properties, but given recent experience, there's a ~1/6 chance that 

it's a binary object.


This object will brighten to about 12th magnitude in mid-January

when it will be a good target for photometric and spectroscopic observations.



Due to its diameter and the proximity of its orbit to Earth, 2005 WJ56 has been 

classified as a "Potentially Hazardous Asteroid" by the Minor Planet Center.



Orbital and Physical Characteristics

 orbit type               Apollo

 semimajor axis           0.959 AU     

 eccentricity             0.152        

 inclination             21.6°       

 perihelion distance      0.813 AU     

 aphelion distance        1.105 AU     

 absolute magnitude (H)  17.8

 diameter                 870 meters +- a factor of two

 rotation period          unknown

 pole direction           unknown

 lightcurve amplitude     unknown

 spectral class           X    (M. D. Hicks, personal communication)


Last update: 2008 January 08





−−　http://echo.jpl.nasa.gov/asteroids/2005WJ56/2005WJ56_planning.html −−

　＊　地球接近小惑星　わずか約340万キロメートル　＊




2007年3月31日に特異小惑星2006 VV2が地球に最接近する。距離は、わずか
約340万キロメートル（月までの8.8倍）となり、9等級まで明るくなると予測されて
いる。また、3月30日から4月2日頃の光度は10等級となる。





2006 VV2は2006年11月11日に18等級の天体として発見され、地球近傍天体
（NEO）に分類されている。NEOとは、地球に接近する軌道を持つ小惑星や彗星
などの総称だ。





また、2006 VV2の大きさは直径2キロメートルほどと推定されている。
小惑星の中で、このように大きくて明るいものが地球に接近する
ことはめずらしく、次にこのような天体を観測できるチャンスは2036年
となる見込みだ。海外や国内各地の天文台でも観測が予定されているが、
小口径の望遠鏡でも見ることができるので、ぜひ観測してみてほしい。





なお2006 VV2は、3月29日の1時から3時（世界時、以下同様）に、
銀河M82とM81から25分角以内に接近し、3月31日の19時から21時にかけては、
銀河M105、M96とM95に3度以内に接近する。

　＊　関勉さんの発見した小惑星　東亜天文学会　＊




Citation for (3935)




The following citation is from MPC 14633:




(3935) Toatenmongakkai = 1987 PB
     Named in honor of the Oriental Astronomical Association, founded in 1920
by Issei Yamamoto, then professor at the Astronomical Institute at Kyoto
Imperial University.  The O.A.A. is mainly composed of amateur astronomers in
Japan.  The discoverer joined the O.A.A. in 1947 and has served as director
of the Comet Section since 1970.


A complete set of naming citations of the numbered minor planets is available in the 
Dictionary of Minor Planet Names, edited by Lutz Schmadel.




東亜天文学会(3935 Toatenmongakkai)は、1987年8月14日に関勉が高知県芸西村で発見した小惑星である。日本で最も古い天文同好会である東亜天文学会にちなんで命名された。