when was the crab nebula discovered

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
when was the crab nebula discovered	1.85	0.4	8584	84	35
when	0.29	0.7	7163	72	4
was	1.8	1	3112	7	3
the	0.25	0.1	8917	88	3
crab	1.37	0.4	5301	9	4
nebula	0.89	0.5	7890	10	6
discovered	0.64	0.7	8299	76	10

Keyword	CPC	PCC	Volume	Score
when was the crab nebula discovered	0.68	0.5	4605	57
who discovered the crab nebula	1.43	0.3	6830	23
how was the crab nebula created	1.21	0.9	794	39
who named the crab nebula	1.62	0.5	3921	48
when did the crab nebula explode	0.1	0.1	8509	17
when did the crab nebula supernova occur	1.13	0.6	2550	59
how old is the crab nebula	0.86	0.6	2584	88
the crab nebula facts	1.3	0.5	9106	26
images of the crab nebula	1.09	0.6	1798	55
pictures of the crab nebula	1.19	0.2	1377	35
interesting facts about the crab nebula	0.71	1	938	21
how to find the crab nebula	0.15	0.2	2350	97
where is the crab nebula located	1.75	0.8	7511	93
nasa crab nebula image	0.71	1	8458	30
location of crab nebula	0.87	0.5	1547	40