Wikipedia:Featured article candidates/Epsilon Eridani/archive2


 * The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was promoted by Ucucha 18:13, 14 November 2011.

Epsilon Eridani

 * Nominator(s): RJH (talk) 17:22, 21 October 2011 (UTC)

I am nominating this article about an interesting nearby star for featured article status because I believe it satisfies the criteria. During the first FAC review the article received numerous comments with three supports and no opposes. However, based on the comments I requested that the nomination be withdrawn pending an expert review. The page has since undergone a second PR and I've attempted to address fixes to resolve the concerns, as well as make general improvements based in part on further comments on the talk page. Please let me know if there are any issues remaining and I'll try to address them during the FAC lifecycle. Thank you. Regards, RJH (talk) 17:22, 21 October 2011 (UTC)

P.S. I sent a request to the Joint Astronomy Centre in Hawaii requesting permission to use their submillimetre wavelength image of the dust ring, but I never received a reply. For that reason I haven't included the image in the article.
 * I am making an inquiry to the JAC and also to the lead scientist to see about using that image. AstroCog (talk) 12:16, 24 October 2011 (UTC)
 * Here's the dust ring image, now at File:Epsilon_eridani_dustring.gif. AstroCog (talk) 21:51, 26 October 2011 (UTC)
 * Well, because of the OTRS backlog, some overzealous admin has deleted the image (despite OTRS providing a message saying to NOT DELETE the image because of the permissions backlog). *sigh* AstroCog (talk) 04:11, 11 November 2011 (UTC)
 * Scratch that - OTRS restored the image and it is now verified and ready for use! AstroCog (talk) 18:59, 11 November 2011 (UTC)
 * That looks excellent. Thank you! RJH (talk) 20:15, 11 November 2011 (UTC)

Source review - spotchecks not done, no comment on comprehensiveness or subject-specific reliability. Nikkimaria (talk) 19:59, 21 October 2011 (UTC)
 * Don't need retrieval dates for convenience links like Google Books
 * I removed the access date in the handful of cases where there was a clear-cut link, per Convenience link.
 * Be consistent in whether or not you provide publisher locations
 * In three of the instances, the location is the place where the conference was held. For two others, the location was provided because the book was too old to have an ISBN so I wanted to have additional information provided for convenience during a look up. I guess that means I have to list a location for every book? Okay, I've done so.
 * Compare formatting on FNs 1 and 10
 * Fixed.
 * When using "et al.", be consistent in whether you list three authors first or only one
 * Fixed.
 * Be consistent in how editions are notated
 * Fixed.
 * External links formatting should match citations. Nikkimaria (talk) 19:59, 21 October 2011 (UTC)
 * I changed them to use citation templates.
 * Thank you Nikkimaria. Regards, RJH (talk) 12:30, 22 October 2011 (UTC)

First of all, thanks for working on this article. I will nitpick the lead a bit (when, if not during an FA? ;) and hopefully make comments about the article body as soon as I get to it. Feel free to reply/argue as these are suggestions.

Lead Hekerui (talk) 22:16, 23 October 2011 (UTC)
 * "closest star known to host an orbiting planet" - why orbiting? aren't all planets hosted by a star orbiting? also, shouldn't it be "star closest to the Sun known to host a planet"?
 * I think I just chose the wording for clarity; I didn't want a reader to think it was floating inside or some such thing. Fixed.
 * "present-day Sun" - "present-day" is redundant
 * Well perhaps, but see "present day". The magnetic activity of the Sun varies somewhat, so I could say something like "a higher level of magnetic activity than the average level for the present Sun". But that seems a little awkward.
 * Ah, in retrospect I think I may have misunderstood your meaning. Sorry. The "present-day" is used to clarify that the comparison is not with the Sun when it was the same age as Epsilon Eridani. In that case, the activity of the Sun was likely higher than at present.
 * "relatively rapid" - compared to what? that is vague and could be left off if we don't bother to explain
 * Resolved by removing. I'll leave the comparison for later. (Too many comparisons to the Sun may make for tiresome reading, I think.)
 * "both smaller and less massive than the Sun" - "both" is redundant
 * Fixed.
 * "which means the energy being generated at the core through nuclear fusion of hydrogen is emitted from the surface at a temperature of about 5,000 K" - why not stick to the surface temperature only? the spectral class does not make statements about the core. imo this is not the place to explain energy production in stars (especially because it doesn't read smoothly)
 * The fusion statement is used to explain the earlier jargon about "main sequence". I tweaked the wording slightly. Does that read better?
 * "The motion of this star along the line of sight to the Earth, its radial velocity ..." - why first the explanation and then the thing explained?
 * Mmm, for variety I suppose. I tweaked the wording slightly.
 * "where 1 AU is the mean distance between the Earth and the Sun: 149.6 million kilometers" I don't think the exact number of kilometers belongs in the lead, no?
 * AU is used throughout the article, so I thought the amount should be listed early on. But I'll yank it out and let the reader follow the link.
 * "In addition, Epsilon Eridani harbors ..." - "in addition" is redundant wording when immediately followed by what is meant
 * Fixed, although it reads awkwardly now.
 * why link as our galaxy instead of writing plainly "the Milky Way"? it's hardly a surprise to the reader.
 * I'm not sure why. It's fixed now.
 * "orbiting planet" - again the orbiting
 * Fixed, I think. In some cases it's just convenient wording that conveys motion.
 * "multiple SETI searches" - "searches" implies plural, so "multiple" is redundant
 * Fixed.
 * Thank you for your comments and observations, Hekerui. Regards, RJH (talk) 23:56, 23 October 2011 (UTC)

Support, provisionally. This is an impressive article for a highly-notable object. Reading through it, the only thing that popped out for me was the description of the proposed interstellar mission (British Planetary Society) in the SETI section. Such a mission isn't necessarily SETI, unless a specific goal of the mission was to "seek out new life", so to speak. RJH, can you comment on this? The reference only goes to the abstract, and not the paper, so I can't immediately check on it. I'm just wondering if this sentence could be placed in a different section. AstroCog (talk) 12:29, 24 October 2011 (UTC)
 * Thank you, Astrocog. Yes you're right, I grouped together two different but somewhat related activities under that name in the interest of keeping the title brief. I changed it to "SETI and proposed exploration". Is that all right, or is there a better title? Thank you. Regards, RJH (talk) 13:35, 24 October 2011 (UTC)
 * Yes, that's a good solution. I was going to suggest just changing the section title, but I forgot. You've got my full support here. AstroCog (talk) 13:59, 24 October 2011 (UTC)
 * Also, the image from JCMT will soon be available. I contacted the lead scientist and she was enthusiastic about allowing the image to be used. Apparently, the outreach position no longer exists, so that's why you didn't get a response. I'm just waiting to get a consent agreement back from the JCMT/JAC director. Once I get it, I can upload the image to the commons if it isn't already there. AstroCog (talk) 14:14, 24 October 2011 (UTC)
 * That will be great. It will really help illustrate the finding. Thank you for your help. Regards, RJH (talk) 16:23, 24 October 2011 (UTC)

I have some copyright concerns with the constellation map used in the infobox. I actually brought this up for all of the constellation maps currently used, which were swapped without discussion (see Wikipedia_talk:WikiProject_Astronomy), but haven't had a response. The new versions certainly look nicer, but have been lifted from the IAU website without any evidence of the license (that I could find). There are also both IAU and Sky & Telescope logos on it. Could someone more familiar with image copyrights than I am take a look at this? Otherwise this article seems excellent. Modest Genius talk 22:46, 24 October 2011 (UTC)
 * Thanks Modest Genius. Yes, that would be a problem. In this case, I've temporarily addressed it by replacing the map with a version that has a CC license. However, the image use policy linked on the IAU source page says they are "released under the Creative Commons Attribution 3.0 Unported license", which matches the license on the Wikimedia Commons. Regards, RJH (talk) 00:25, 25 October 2011 (UTC)


 * Thanks for that, I did have a hunt at the time but am not sure how I missed that page! That doesn't seem to require that we include the logos, but otherwise checks out. For the record you might like to point this out on the WT:ASTRO 'discussion'. Regardless, the image now used in the article is certainly fine. Modest Genius talk 10:52, 25 October 2011 (UTC)
 * Yes, for some reason they used a very tiny font size for the copyright link. Thank you. Regards, RJH (talk) 14:19, 25 October 2011 (UTC)


 * Support Comments  looking over now - looks more polished than last time so am suspecting it'll pass this time. Notes below: Casliber (talk · contribs) 01:42, 25 October 2011 (UTC)


 * Regarding the lead, it does read a little oddly, having, "...is the closest star known to host a planet." (i.e. a certainty), followed by, "Periodic changes in this data yield evidence of a giant planet orbiting Epsilon Eridani, making it the nearest extrasolar system with a candidate exoplanet" (a possibility). Making the second sentence past tense (i.e. "yielded") helps a little. I think it helps to gather discussion of planets into one segment rather than in two places in the lead.

Otherwise I am finding very little to tweak or improve...well done. Casliber (talk · contribs) 02:11, 25 October 2011 (UTC)
 * Thanks Casliber. Well I have mixed feelings about this. To me, putting in a statement about the planet early in the presentation is important, as it is one of the primary distinguishing characteristics of the star. But I didn't think the first paragraph should be just about the planet, since the article is primarily about the star. Hence this is something of a compromise, and I'm kind of okay with this arrangement. Sorry. I changed "yield" to "yielded", per your suggestion, making the lead-in to the second paragraph more of a history. Regards, RJH (talk) 04:27, 25 October 2011 (UTC)
 * (sigh) I know, I think it can be argued that way validly, hence not a deal-breaker, hence happy with over-the-linehood Featured candidacy. Casliber (talk · contribs) 11:55, 25 October 2011 (UTC)
 * Thank you, Casliber. Regards, RJH (talk) 14:19, 25 October 2011 (UTC)

 Comment  I'll review in detail in a couple of days, but for now please note that there is no observatory at the Cape of Good Hope, it's in Observatory, Cape Town  Jimfbleak -  talk to me?  16:32, 25 October 2011 (UTC)
 * Hello Jimfbleak. Is that true as of 1883? Please see the ref. Regards, RJH (talk) 16:41, 25 October 2011 (UTC)
 * The observatory, despite its name, has been in Cape Town since 1920, and the main telescope still there (most are in the north cape now) dates from 1897. Your "ref" just gives chapter headings, no useful content, so I don't how it supports a location on the Cape of Good Hope (or anything else for that matter)  Jimfbleak -  talk to me?  17:36, 25 October 2011 (UTC)
 * Understood. Well, I was going by the article title used in Gill (1893). But, of course, he's just the astronomer who worked there at the time, so perhaps he's mistaken. ;-) However, the citation does support the parallax listed in the article, so it is of some use.


 * Apparently the Astronomical Society of Southern Africa uses the name "Royal Observatory at the Cape of Good Hope ... Also referred to as the Cape Observatory, 1820 - 1968". Likewise, the South African Astronomical Observatory article refers to the Royal Observatory, Cape of Good Hope. David Gill (1920) gives a History and description of the Royal Observatory Cape of Good Hope. According to SAAO: the Nutshell History, the Royal Observatory at the Cape of Good Hope was founded in 1820, and later formed part of South African Astronomical Observatory.


 * At this point I am unclear how to proceed. Any suggestions? Regards, RJH (talk) 19:05, 25 October 2011 (UTC)


 * In 1883 it was called The Royal Observatory at the Cape of Good Hope, sometimes given as Royal Observatory, Cape of Good Hope. It was renamed the South African Astronomical Observatory when several observatories in the country were merged and transferred to South African control in 1972. There's even a plaque on the main building of the SAAO which carries this information. However, Jimfbleak is correct in that the observatory was not actually sited on the Cape of Good Hope itself, but quite a few miles north, originally quite a way outside Cape Town but now one of the suburbs. Observatory, Cape Town is the name of the suburb which grew up in the nearby area. I've therefore corrected the link in the article to point to the observatory itself rather than the geographic feature. (fwiw, I used to work at the SAAO). Modest Genius talk 20:06, 25 October 2011 (UTC)
 * Thank you. Regards, RJH (talk) 20:29, 25 October 2011 (UTC)
 * Thanks, I didn't make a very good job of conveying that point, that despite what it's called, it's never actually been at the Cape. I should have fixed the link myself really  Jimfbleak -  talk to me?  20:30, 25 October 2011 (UTC)

Support More comments   Jimfbleak -  talk to me?  10:15, 26 October 2011 (UTC) Thank you for your comments and observations, Jimfbleak. Regards, RJH (talk) 18:43, 26 October 2011 (UTC)
 * Dutch-American astronomer &mdash; Was he a naturalised American? His own Wikipedia article doesn't say that.
 * The only thing I could find was that he emigrated to the U.S. in 1923. There was nothing about citizenship, even in his obituary. At any rate, it doesn't seem quite applicable to this article.
 * However, the somewhat low abundance of heavy elements is normally indicative of an older star. &mdash; I thought older stars burned helium, carbon etc to create more heavy atoms. Can you clarify?
 * I've inserted a brief explanation. Does that make it clearer?
 * The star appears in numerous science fiction stories &mdash; the lead should summarise the article, but the books/TV/games are relegated to "See also". I think you need to say something about this aspect in the main article for it to be comprehensive
 * I found a source that allowed me to add a relevant observation to the article. Otherwise, there doesn't appear to be much else to say. The Epsilon Eridani in fiction article contains a long list of unsourced trivia and provides no other themes to tie the lot together.
 * Unless I've missed something, the last point isn't resolved. Firstly, you shouldn't have any references in the lead, they should occur where the topic is dealt with in the text. Secondly, there is still nothing about the sci-fi in the text, so you can't be summarising it in the lead. If the sci-fi isn't notable, take it out, otherwise add something to potential habitability like The proximity, Sun-like properties and suspected planets of this star have also made it the subject of multiple studies on whether an interstellar probe can be sent to Epsilon Eridani,(refs) and a popular destination for interstellar travel in numerous science fiction stories. (Boyle ref) Once the refs in the lead and this issue are resolved I'll be happy to support  Jimfbleak - </b> talk to me?  06:00, 27 October 2011 (UTC)
 * It looks like you missed the addition: "Despite this lack of success, Epsilon Eridani made its way into science fiction literature and television shows for many years following news of Drake's initial experiment." But I've added another mention in the "Potential habitability" section. The point about the interstellar probes is already covered in "SETI and proposed exploration".
 * Actually Jimfbleak, you are allowed to have some references in the lead. In fact you can almost not avoid it, because that seems to be the part of an article that is most likely to be challenged by visitors. See: WP:LEADCITE.
 * Regards, RJH (talk) 14:33, 27 October 2011 (UTC)
 * Fair enough, I've indicated my support above <b style="font-family:chiller; color:red;"> Jimfbleak - </b> talk to me?  14:56, 28 October 2011 (UTC)
 * Thank you. Regards, RJH (talk) 14:58, 28 October 2011 (UTC)

Before this article can be promoted, I'd like to see a full image review and a spotcheck of the sources. Ucucha (talk) 15:06, 6 November 2011 (UTC)
 * I just reviewed all the images - all are from the commons and are either public domain images or have a CC 3.0 license. Note that one image is likely to be added: Epsilon Eridani dust ring, but the backlog from OTRS has prevented it from being reviewed. Could an administrator do something about that? AstroCog (talk) 15:59, 6 November 2011 (UTC)
 * I also checked the current images (without the dust ring), all are fine. Hekerui (talk) 10:08, 10 November 2011 (UTC)
 * Source spotcheck: As a spot check for the article, I checked all the sources in the "observation history" and "properties" sections except the books, which I couldn't access, and the content looks fine copyright- and fact-wise. I found it hard to discern the negative result for ε Eri in the Heintz paper, but that's probably me not understanding the table or overlooking a specific discussion (no search function in scanned articles). Hekerui (talk) 11:44, 10 November 2011 (UTC)
 * In the Heintz paper, the note on eps Eri is towards the end of page 1192, under the alternative name BD -9 697. It confirms the absence of an astrometric orbit, and does blame it on a misalignment in the telescope used for the earlier work. Checks out. <b style="font-family:Times New Roman; color:maroon;">Modest Genius</b> talk 14:07, 10 November 2011 (UTC)
 * Yeah, sorry, I usually read the notes to the citations, but somehow didn't do it here and looked for other alternative names (too many!). Hekerui (talk) 12:07, 11 November 2011 (UTC)

Hekerui (talk) 14:00, 10 November 2011 (UTC)
 * Minor things:
 * Observation history:
 * "The experiment was repeated by Drake in 2010..." - they checked for an hour, a fraction of the time of the original experiment... I have no problem with it staying in, but it seems insignificant and hardly worthy of mention, no?
 * Although they don't say it in the article, I suspect that the technology is much improved in 2010, compared to what was available in 1960. This should allow shorter observations to produce the same or a better level of analysis. Hence, I can't really say whether the 2010 observation was any less thorough than the 1960 observation. Beyond that, I suppose it is only of minor historical interest. But it did receive some coverage in the press, so I guess that it is "notable" in the Wikipedia sense. RJH (talk)
 * What does "unimpeachable signal" mean? Perhaps more plain language should be used to explain that nothing was found.
 * The word "unimpeachable" is in my small, portable dictionary. Sorry, but I don't see a need to dumb Wikipedia down that far. :-) RJH (talk)
 * Properties:
 * "13th nearest known star" - maybe one should add "as of 2007", the source date, to not conflict with List of nearest stars, although the distance error of WISE 1541-2250 is enormous
 * WISE 1541-2250 is a brown dwarf; a substellar object. I don't know that it should be counted as a star. How likely do you think it is that astronomers missed an intervening star? I suppose there could be a compact object. Okay, I'll add a proviso. RJH (talk)
 * "relatively little net motion" - should be reworded, is vague: what is relatively little, what is net motion?
 * Fixed. The 'net motion' would be per the motion of plasma in a convective zone. RJH (talk)
 * "The magnetic properties can be modeled by assuming ..." - the paper abstract suggests that the 9% are the result of analysis, not a modelling assumption, or not?
 * See p. 950, "For our adopted model of &epsilon; Eri...". RJH (talk)
 * the mention of 1788 days is perhaps unnecessary detail, considering how the 1788 days mention is followed in the text by "with a false alarm probability (FAP) of 22%" (unless I misunderstood) - the Gray/Baliunas paper abstract only uses "about 5 years"
 * Okay, I changed the text to say 4.9 years, per the reference, which is pretty close to 1788 days. RJH (talk)
 * "about the mean" - could be clearer, is "the mean" the estimated surface temperature? I can't tell from a quick glance at the paper either.
 * I removed "about the mean", as it seems to be already implied by "variations". RJH (talk)
 * "the age may be as low as 500 million or as high as a billion years" - I have difficulty seeing the range in the paper, the closest ageI found was a mention of 730+200=930 Ma - have I overlooked this?
 * I sorted the sentence on the age of ε Eri new to try to make the logical step from the last sentence to this one clearer, but I'm still not happy with it. I understand the age argument because I know what is meant, but for a reader who doesn't, the sentence should probably be reformulated and/or split to be easier to grasp.
 * The original range came from a reference that I am unable to track down now. Per the two bullets above, I rewrote the age estimation information based on Janson et al. (2008), which seems pretty comprehensive. Hopefully it is better now. RJH (talk)
 * Thank you for your comments, observations and edits. Regards, RJH (talk)

Sorry for the slow trickle this late: Hekerui (talk) 11:55, 11 November 2011 (UTC)
 * Properties:
 * the association of the star with the Ursa Major Moving Group is asserted with "indicates", but the newer (2008) source discusses that as "not very convincing" - I think the article doesn't reflect that uncertainty, especially in the lead
 * Fair enough. I changed the two instances of "is" to "may be". Thanks. RJH (talk) 15:57, 11 November 2011 (UTC)
 * "estimated age of this group is 500 ± 100 million years, which does not differ significantly from the current age" - I have not found the conclusion in the source about the group age not differing significantly from ε Eridani's, which would make it original research and problematic considering how badly known the age of the star is according to the article
 * That's just a common sense observation, for the benefit of the reader, to point out that it fits in with the range of age estimates for the star, rather than being radically off. I suppose it could just as easily say, "which lies within the range of the age estimates for the star". I used the King et al. (2003) estimate for the group rather than Fuhrmann (2004), because I don't have access to the latter and I don't know whether Fuhrmann would carry more weight. In either case they are both roughly in the right ballpark. RJH (talk)


 * Note 1 seems to be missing something, it ends with a line containing just "See." <b style="font-family:Times New Roman; color:maroon;">Modest Genius</b> talk 13:13, 12 November 2011 (UTC)
 * True, that needs to cite the Fröhlich source. Hekerui (talk) 13:23, 12 November 2011 (UTC)
 * I've restored the citation to the note. Sorry about that, and thank you for the catch. Regards, RJH (talk) 18:32, 12 November 2011 (UTC)


 * The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.