A “strange” unit radio astronomy












1












$begingroup$


I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:




Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$




I'm guessing it's "Watts per square meter per something per second", but I'm not sure what the something is.



A similar unit appears in this paper on the first line on page 364:




The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.




Again, this looks to me like megasomething. Can anyone shed some light on this?



On page 362 of the second paper, the unit appears as $(Watts/M^2
)/(C/S)$ as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.






radio-astronomy units







share|improve this question











$endgroup$

















    1












    $begingroup$


    I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:




    Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$




    I'm guessing it's "Watts per square meter per something per second", but I'm not sure what the something is.



    A similar unit appears in this paper on the first line on page 364:




    The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.




    Again, this looks to me like megasomething. Can anyone shed some light on this?



    On page 362 of the second paper, the unit appears as $(Watts/M^2
    )/(C/S)$     as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.






    radio-astronomy units







    share|improve this question











    $endgroup$















      1












      1








      1





      $begingroup$


      I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:




      Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$




      I'm guessing it's "Watts per square meter per something per second", but I'm not sure what the something is.



      A similar unit appears in this paper on the first line on page 364:




      The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.




      Again, this looks to me like megasomething. Can anyone shed some light on this?



      On page 362 of the second paper, the unit appears as $(Watts/M^2
      )/(C/S)$       as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.






      radio-astronomy units







      share|improve this question











      $endgroup$




      I'm reading up on radio astronomy, and I came across this paper from 1964. At the bottom of page 193, the author uses a unit that I've not seen before in discussing radio power emission from stars:




      Now the outbursts on the Sun give an intensity on Earth of $10^{19}$ to $10^{20}$ $wm^{-2}(c/s)^{-1}$




      I'm guessing it's "Watts per square meter per something per second", but I'm not sure what the something is.



      A similar unit appears in this paper on the first line on page 364:




      The comparison band in the radiometer, being separated approximately 3.25 Mc from the signal band, never encounters the hydrogen range of frequencies.




      Again, this looks to me like megasomething. Can anyone shed some light on this?



      On page 362 of the second paper, the unit appears as $(Watts/M^2
      )/(C/S)$       as a unit of flux. There, the $C$ looks like coulombs, but that makes the $3.25 Mc$ in the second quote seem weird.






      radio-astronomy units




      radio-astronomy units






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited 5 hours ago







      Jim421616

















      asked 5 hours ago









      Jim421616Jim421616

      569211




      569211






















          1 Answer
          1






          active

          oldest

          votes


















          3












          $begingroup$

          I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
          $$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
          One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.






          share|improve this answer









          $endgroup$









          • 1




            $begingroup$
            The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
            $endgroup$
            – Jim421616
            4 hours ago











          Your Answer





          StackExchange.ifUsing("editor", function () {
          return StackExchange.using("mathjaxEditing", function () {
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
          });
          });
          }, "mathjax-editing");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "514"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: false,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fastronomy.stackexchange.com%2fquestions%2f29863%2fa-strange-unit-radio-astronomy%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          3












          $begingroup$

          I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
          $$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
          One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.






          share|improve this answer









          $endgroup$









          • 1




            $begingroup$
            The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
            $endgroup$
            – Jim421616
            4 hours ago
















          3












          $begingroup$

          I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
          $$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
          One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.






          share|improve this answer









          $endgroup$









          • 1




            $begingroup$
            The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
            $endgroup$
            – Jim421616
            4 hours ago














          3












          3








          3





          $begingroup$

          I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
          $$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
          One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.






          share|improve this answer









          $endgroup$



          I would expect the authors to be talking about the signal in terms of janskys, the now-commonly-used units of flux density. The typical definition is
          $$1text{ Jansky}=10^{-26}text{ Watts meters}^{-2}text{ Hertz}^{-1}$$
          One Hertz is one cycle per second, which makes me suspect that the "c" stands for cycle. It does seem curious that the authors choose to use cycles/second instead of Hertz, but that could be simply a convention of the time.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered 4 hours ago









          HDE 226868♦HDE 226868

          20k265125




          20k265125








          • 1




            $begingroup$
            The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
            $endgroup$
            – Jim421616
            4 hours ago














          • 1




            $begingroup$
            The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
            $endgroup$
            – Jim421616
            4 hours ago








          1




          1




          $begingroup$
          The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
          $endgroup$
          – Jim421616
          4 hours ago




          $begingroup$
          The fact that they are from older papers makes me agree with you, that it's an old convention. Jansky is consistent with flux. Thanks!
          $endgroup$
          – Jim421616
          4 hours ago


















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Astronomy Stack Exchange!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid …



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          Use MathJax to format equations. MathJax reference.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fastronomy.stackexchange.com%2fquestions%2f29863%2fa-strange-unit-radio-astronomy%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          -

          Popular posts from this blog

          SQL Server 17 - Attemping to backup to remote NAS but Access is denied

          Image
          .everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0; } 0 I was attemping to use Ola Hallengrens scripts to backup to a remote NAS, but it was failing and not giving any direct errors, so I tried doing it manually using Server Management Studio and got the following error: TITLE: Microsoft SQL Server Management Studio Failed to retrieve data for this request. (Microsoft.SqlServer.Management.Sdk.Sfc) For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft%20SQL%20Server&LinkId=20476 ADDITIONAL INFORMATION: An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo) The operating system returned the error '0x80070005(Access is denied.)&#
          Read more

          Always On Availability groups resolving state after failover - Remote harden of transaction...

          Image
          0 My explanation will be opinion based as it is based on my findings. If more information is needed, I am always happy to add it. The setup We have 4 SQL Server 2016 Instances, and all 4 underlying servers are in a WSFC (In my eyes a strange setup since Always On AG's are 2 by 2. But that is a different question.) 4 nodes + Fileshare witness Version: 13.0.5026.0 (all nodes) The instances that are having the failover issues are instances 1 & 2. They have 3 AG's between them. AG1 is primary on instance 1 and is having the issue. AG2 and AG3 are primary on instance 2. Instances 3 and 4 have their own separate AG's (2). AG1's settings The week before Last week, after checking for long running queries (none) and the synchronization state (green accross the board) we initiated a
          Read more

          Restoring from pg_dump with foreign key constraints

          Image
          5 2 In restoring a database from a pg_dump , a number of errors are being generated and the whole table is subsequently being ignored. An example: ERROR: insert or update on table "channelproducts" violates foreign key constraint "fk_rails_dfaae373a5" DETAIL: Key (channel_id)=(1) is not present in table "channels". Interestingly enough, I've noted that all these instances are popping up because of the sequence of loading. channels is after channelproducts both alphabetically and in the file and thus I can understand why postgres complains about having to create a child without a parent. caveat: the foreign key is being generated automatically by rails 4.2: I could remove the problem at the source but that still does not really solve the problem... version: PostgreSQL
          Read more