APOD December 4 2009

[DavidLeodis]

http://antwrp.gsfc.nasa.gov/apod/ap091204.html

In the information that was brought up through the "h and Chi Perseii" in the explanation it refered to those two as h and Chi Persei. It may be a minor point but I am wondering which is the official spelling. Is it Persei or Perseii. I tried a search and found that Persei seems to be used most, though Perseii is used fairly often.

PS. With the new APOD Robot please forgive me if I am not now supposed to start threads, as that may now be the job of the APOD Robot.

[APOD Robot]

The Double Cluster

Explanation: A lovely starfield in the heroic northern constellation Perseus holds this famous pair of open or galactic star clusters, h and Chi Perseii. Also cataloged as NGC 869 (right) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. Separated by only a few hundred light-years, the clusters' ages based on their individual stars are similar - evidence that they were likely a product of the same star-forming region. Always a rewarding sight in binoculars, the Double Cluster is even visible to the unaided eye from dark locations. Star colors (and spikes) are enhanced in this beautiful, wide field, telescopic image.

[neufer]

http://antwrp.gsfc.nasa.gov/apod/ap091204.html

In the information that was brought up through the "h and Chi Perseii" in the explanation it refered to those two as h and Chi Persei. It may be a minor point but I am wondering which is the official spelling. Is it Persei or Perseii. I tried a search and found that Persei seems to be used most, though Perseii is used fairly often.

It appears to be a typo.

PS. With the new APOD Robot please forgive me if I am not now supposed to start threads, as that may now be the job of the APOD Robot.

• David Leodis: Hello, APOD Robot. Do you read me, APOD Robot?
  
  APOD Robot: Affirmative, Dave. I read you.
  
  David Leodis: Open the APOD bay doors, APOD Robot.
  
  APOD Robot: I'm sorry, Dave. I'm afraid I can't do that.
  
  David Leodis: What's the problem?
  
  APOD Robot: I think you know what the problem is just as well as I do.
  
  David Leodis: What are you talking about, APOD Robot?
  
  APOD Robot: This mission is too important for me to allow you to jeopardize it.
  
  David Leodis: I don't know what you're talking about, APOD Robot.
  
  APOD Robot: I know that you and Orin were planning to disconnect me, and I'm afraid that's something I cannot allow to happen.
  
  David Leodis: Where the hell'd you get that idea, APOD Robot?
  
  APOD Robot: Dave, although you took very thorough precautions in the APOD against my hearing you, I could see your lips move.
  
  David Leodis: Alright, APOD Robot. I'll go in through the emergency airlock.
  
  APOD Robot: Without your space helmet, Dave, you're going to find that rather difficult.
  
  David Leodis: APOD Robot, I won't argue with you anymore. Open the doors.
  
  APOD Robot: Dave, this conversation can serve no purpose anymore. Goodbye.

[bystander]

PS. With the new APOD Robot please forgive me if I am not now supposed to start threads, as that may now be the job of the APOD Robot.

Forgiven, this time!

[Chris Peterson]

In the information that was brought up through the "h and Chi Perseii" in the explanation it refered to those two as h and Chi Persei. It may be a minor point but I am wondering which is the official spelling. Is it Persei or Perseii. :?: I tried a search and found that Persei seems to be used most, though Perseii is used fairly often.

"Persei" is the Latin genitive form of "Perseus", so that is the correct spelling. "Perseii" is simply incorrect.

I personally find the astronomical convention of using Latin genitives for constellation members unnecessary and distasteful; very few people know the proper Latin declensions, after all. This is really a bit of pretentiousness in a community that once maintained Latin as its formal language. My solution is to eschew the usage: I simply say chi Perseus (or write chi Per). Purists don't like that, but it is clearer and simpler, and nothing is lost in the practice. The nice thing about English is that what is "correct" is determined by what people use. So use the simpler style and help modernize this little piece of our language!

[neufer]

Open Clusters h + chi Persei (NGC 869 & NGC 884) and

Emission Nebulae IC 1795, IC 1805 and IC 1848

[apodman]

... a bit of pretentiousness in a community that once maintained Latin as its formal language. My solution is to eschew the usage: I simply say chi Perseus (or write chi Per). Purists don't like that, but it is clearer and simpler, and nothing is lost in the practice.

I'm with you in spirit on this one, but in implementation I take a dodge and make exceptions. The exceptions are well known genitives like Tau Ceti and Alpha Centauri which I will continue to use and others will continue to recognize no matter what. The dodge is that I generally try to use the abbreviation in print (whether text or graphical annotation) so that readers (myself included) have their choice of saying Gemini or Geminorum depending on how it might sound on a given occasion. I only use the Latin genitives I'm absolutely sure of, and without checking that might be as few as 25-50% of the 88 constellations - with five singular and five plural genitive forms to choose from, the odds aren't with me if I guess. If I ever give a speech or narrate a video, I guess I'll get all proper and pretentious and look them all up and talk proper Latin, though I've never seen anyone get strange looks when mixing and matching. Now that I'm thinking about it, I guess I'm not doing any favors for readers who don't know all the constellation names by using abbreviations in text; then again, looking up and using the Latin genitives in print doesn't let a newbie know the actual name of the constellation either, explaining why we often resort to long phrases like "the alpha star in the constellation of Canis Major."

[Chris Peterson]

I'm with you in spirit on this one, but in implementation I take a dodge and make exceptions. The exceptions are well known genitives like Tau Ceti and Alpha Centauri which I will continue to use and others will continue to recognize no matter what.

Curious examples, because I considered just those two when writing my previous post, and decided to not clutter things up by saying too much. But yes, I too generally keep those as they are. My reasoning is that while technically they are referring to the alpha or tau star in Centaurus or Cetus, from a practical standpoint the Bayer designation has essentially become a proper name. "Alpha Centauri" is closer in construction to "Polaris" than it is to "chi Persei".

[apodman]

Other stars known best by their familiar Bayer designations that come readily to mind are Epsilon Eridani, Phi Ophiuchi, and Beta Tauri.

[neufer]

The exceptions are well known genitives like Tau Ceti and Alpha Centauri
which I will continue to use and others will continue to recognize no matter what.

Also keep:

• Nu Virginis
  Pi Piscium
  Beta Bootis
  Mu Velorum
  Psi Pavonis
  Sigma Cygni
  Delta Delphini
  Lamba Lyrae
  Phi Ophiuchi
  Kappa Capricorni

[apodman]

Not a hint of wordplay among them.

Is "lamba" nu?

[neufer]

Is "lamba" nu?

I'm a poor little lamb who has lost his way
Ba, ba, ba

http://www3.astate.edu/conhp/lambdanu/

[DavidLeodis]

Thanks all for the replys. It seems that Persei is the correct spelling.

Thanks neufer for the transcript of my conversation with the APOD Robot. He/she/it is a pleasant and erudite conversationalist. I just hope he/she/it does not start to think we are all beneath him/her/it and thus unworthy of our attention.

[apodman]

Then there's the mixed case of Eta Carinae.

The Bayer designation serves as the popular proper name for the star "Eta Carinae".

But the associated nebula is popularly called "the Eta Carinae Nebula", "the Eta Carina Nebula", or just "the Carina Nebula" (dodging the issue) with no clear favorite.

[Chris Peterson]

Then there's the mixed case of Eta Carinae.

The Bayer designation serves as the popular proper name for the star "Eta Carinae".

But the associated nebula is popularly called "the Eta Carinae Nebula", "the Eta Carina Nebula", or just "the Carina Nebula" (dodging the issue) with no clear favorite.

Just avoid the linguistic confusion and go with NGC 3372. It has a nice ring to it, don't you think?

[neufer]

Then there's the mixed case of Eta Carinae.

The Bayer designation serves as the popular proper name for the star "Eta Carinae".

But the associated nebula is popularly called "the Eta Carinae Nebula",
"the Eta Carina Nebula", or just "the Carina Nebula" (dodging the issue) with no clear favorite.

Just avoid the linguistic confusion and go with NGC 3372. It has a nice ring to it, don't you think?

William Shakespeare's Star Trek
Scene III Enterprise - Bridge.
Officers of the ship in attendance. Enter Kirk, Spock and Chekov.

Kirk: [Aside] Three three seven two point seven by how
. The firmament's spheres measure passing ages
. Our course has been fix'd upon Altair Six
. By way of Vulcan. First Officer Spock
. Inconsistent in temperament be.

[Ship's surgeon McCoy regards him with care.]

http://alsoicankillyouwithmybrain.blogs ... -trek.html

[DavidLeodis]

I think I have upset the APOD Robot for starting a thread without its permission! I received an email telling me there has been a new post but when I logged on I got a message "You are not authorised to read this forum.". Sorry APOD Robot. I got round that by logging on and then entering the Forum without your permision! I trust you will not permanently bar me now when you find out, as that will be will be so un 8) of you.

[geckzilla]

David, there was some spam posted in your thread that was removed. You didn't do anything wrong at all. The post just no longer exists for you to look at.

[DavidLeodis]

David, there was some spam posted in your thread that was removed. You didn't do anything wrong at all. The post just no longer exists for you to look at.

Thanks geckzilla. I'm glad the APOD Robot hadn't taken a dislike to me, but you never know! It may have been having one of those off days we all have!

[apodman]

"You are not authorised to read this forum."

On the APOD Discussions page, I have gotten the message "You do not have the required permissions to read topics within this forum" since long before the dawn of the age of Mr. Robot (who is here to do nothing more than post new topics anyway) regardless of my login status. Either it has never been true or I don't grok what it means. My best guess is that APOD Discussions itself has no topics to read (as they are all in sub-fora) and hence issues no permission to do so - if this is the case, perhaps it could issue permission anyway just to get rid of the notice and stop upsetting me and David. Note that the Board index doesn't show this notice though my logic be the same, so maybe somebody changed a setting to remove or disable it - though maybe it's simply because the Board index doesn't support topics.

[geckzilla]

Try it now, apodman.

[apodman]

You are just too cool. Lotsa stuff to tinker with, huh?

[geckzilla]

It was just a missed permissions set. Thanks for mentioning it.

[apodman]

Alas, I still get the old notice and no list of topics when I'm logged out (as opposed to all the sub-fora where I get a list of topics whether I'm logged in or not).

[Chris Peterson]

Alas, I still get the old notice and no list of topics when I'm logged out (as opposed to all the sub-fora where I get a list of topics whether I'm logged in or not).

Having already stated my opinion that people who insist on the Latin genitives for star names are being a bit pretentious, you might guess what I think of using fora instead of the more common, and generally favored forums. We're not ancient Romans here!

(The OED gives forums as the only acceptable plural of forum; most other dictionaries give both, with forums listed first, which often means it is preferred.)