यमग्रह

यमग्रह सौर्यमण्डलको सूर्यबाट नवौँ ग्रह हो।^[१] यो ग्रह हिउँ र चट्टानले बनेको छ । यो ग्रह सन् १९३० मा पत्ता लागेको थियो र नवौँ ग्रहको रुपमा घोषणा गरिएको थियो ।^[२] यो ग्रहलाई पृथ्वीबाट बाइनाकुलर र सूक्ष्मदर्शक यन्त्रको मद्दतले हेर्न सकिन्छ । अङ्ग्रेजीमा यसलाई प्लुटो भनिन्छ ।^[३] प्राचीन ग्रिक धर्म अनुसार प्लुटोलाई भूमिगत देवताको रुपमा लिइन्छ । यस ग्रहलाई एस्ट्रा्नोमिकल युनियन (आइएयू)ले सन् २००६ सेप्टेम्बर १ मा ग्रहको सूचिबाट हटाएको थियो।^[४]

सन्दर्भ सामग्रीहरू

↑ Croswell, Ken (१९९७), Planet Quest: The Epic Discovery of Alien Solar Systems, New York: The Free Press, पृ: ४३, आइएसबिएन 978-0-684-83252-4।
↑ For example: "Ninth Planet Discovered on Edge of Solar System: First Found in 84 Years". Associated Press. The New York Times. March 14, 1930. p. 1.
↑ Ernest W. Brown, On the predictions of trans-Neptunian planets from the perturbations of Uranus, PNAS May 15, 1930 16 (5) 364-371.
↑ Stern, S. Alan; Levison, Harold F. (२००२), "Regarding the criteria for planethood and proposed planetary classification schemes", Highlights of Astronomy 12: 205–213, as presented at the XXIVth General Assembly of the IAU–2000 [Manchester, UK, 7–18 August 2000], डिओआई:10.1017/S1539299600013289, बिबकोड:2002HiA....12..205S।

[1] Croswell, Ken (१९९७), Planet Quest: The Epic Discovery of Alien Solar Systems, New York: The Free Press, पृ: ४३, आइएसबिएन 978-0-684-83252-4।

[2] For example: "Ninth Planet Discovered on Edge of Solar System: First Found in 84 Years". Associated Press. The New York Times. March 14, 1930. p. 1.

[3] Ernest W. Brown, On the predictions of trans-Neptunian planets from the perturbations of Uranus, PNAS May 15, 1930 16 (5) 364-371.

[Stern_2002-4] Stern, S. Alan; Levison, Harold F. (२००२), "Regarding the criteria for planethood and proposed planetary classification schemes", Highlights of Astronomy 12: 205–213, as presented at the XXIVth General Assembly of the IAU–2000 [Manchester, UK, 7–18 August 2000], डिओआई:10.1017/S1539299600013289, बिबकोड:2002HiA....12..205S।

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