Based on research and the context, I’m thinking that 共一 is short for 共同第一作者.

“But it seems to be just a supporting role, not a role of my own. It’s over-glorified. Perhaps in the end, it will be a joint first authorship.”

共同第一作者:
http://www.paperpub.com.cn/website/blog/blogcontent.asp?id=4... : 如果确有必要说明两个以上的作者在地位上是相同的, 可采取“共同第一作者”(Joint first authors)的署名方式, 也可在这些作者的姓名旁边使用符号来标识, 并说明“这些作者对研究工作的贡献是相同的” (These authors contributed equally to the work).
http://bit.ly/1b35yOl : 有时候有点奇怪，另外一个人贡献了40％的figures，就算是苦劳给个{共一}也没啥啊，你还是排在最前面的一作。
http://www.weiming.info/zhuti/Biology/31504365/

On joint first authorship:
http://www.oxfordjournals.org/our_journals/nar/for_authors/e...
http://blog.chembark.com/2007/03/29/standardizing-author-ord...
http://www.phd2published.com/2011/09/15/katherine-reekie-pub... : It is possible to have a joint first authorship, when two individuals are considered to have contributed equally towards the work.


--------------------------------------------------
Note added at 2 hrs (2013-10-07 14:18:40 GMT)
--------------------------------------------------

Please check if it fits in the context of the text.

--------------------------------------------------
Note added at 2 hrs (2013-10-07 14:22:31 GMT)
--------------------------------------------------

http://www.websaru.com/打下手.html
打下手: to act in a supporting role, fig. to play second fiddle

--------------------------------------------------
Note added at 2 hrs (2013-10-07 14:25:54 GMT)
--------------------------------------------------

http://www.iciba.com/美其名曰
美其名曰 ： describe euphemistically as “...”; be wrapped in nice-sounding phrases; call it by the fine-sounding name of ...; euphemistically called; give sth. the fine-sounding name of

They dignified cowardice by calling it prudence
他们把怯懦{美其名曰}为谨慎。

They gave this political intervention a dignified name of aid
他们把这种政治干涉{美其名曰}为“援助” 。