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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20966 results found.

  1. GRB 120729A: Swift/UVOT Detection
  2. GRB 120729A: Xinglong TNT optical upper limit
  3. GRB 120728A: Swift/UVOT Upper Limits
  4. GRB 120729A Gemini-N redshift
  5. GRB120729A - Faulkes Telescope North Optical Afterglow Candidate
  6. GRB 120728A: GROND observations
  7. GRB 120727A/Galactic source: Fermi-LAT detection of a transient source
  8. GRB 120724A: JCMT SCUBA-2 sub-mm observation
  9. GRB 120724A: Swift/UVOT Detection of the Optical Afterglow
  10. GRB 120724A: Gemini-N tentative redshift
  11. GRB 120722A: Swift/UVOT Upper Limits
  12. GRB 120722A: VLT/X-shooter redshift of the host galaxy
  13. GRB 120722A: GROND detection of the afterglow
  14. GRB 120722A: 1.5m OSN I-band observations
  15. GRB 120722A: Xinglong TNT optical afterglow candidate
  16. GRB 120716A: EVLA Detection
  17. GRB 120716A: Swift-XRT detection
  18. GRB 120716A: Redshift confirmation from VLT/X-shooter
  19. VLT/FORS2 redshift of GRB120716A
  20. GRB 120716A: GROND confirmation of the optical/NIR afterglow
  21. GRB 120716A: Optical decay from NOT
  22. GRB 120716A: Candidate Optical Afterglow from PTF
  23. GRB 120711A: ATCA 34GHz final observations (upper limit)
  24. GRB 120714B: Swift/UVOT Detection
  25. GRB120714A: Swift/UVOT upper limits
  26. GRB 120714A: GROND upper limits
  27. GRB 120714B: GROND confirmation of fading afterglow
  28. GRB 120714B: Redshift from VLT/X-shooter
  29. GRB 120624B: VLA Observations
  30. GRB 120711A: INTEGRAL/SPI observations
  31. GRB 120714A: Swift-XRT observations
  32. GRB 120711A: ATCA 34GHz further observations (upper limit)
  33. GRB 120712A: Swift/UVOT Detection
  34. GRB 120712A: VLT/Xshooter redshift
  35. GRB 120712A Gemini-S redshift
  36. GRB 120712A: GROND Detection of the Optical/NIR Afterglow Candidate and photo-z
  37. GRB 120711A: ATCA 34GHz upper limit
  38. GRB 120711B: Swift/UVOT Upper Limits
  39. GRB 120711A: Swift/UVOT Observations
  40. GRB 120709A: Swift/UVOT Observations
  41. GRB 120711A: Swift-XRT observations
  42. GRB 120711A Gemini-S likely redshift
  43. GRB 120711A: GROND photometric redshift
  44. GRB 120711A: a possible X-ray transient
  45. Continued Skynet/PROMPT observations of GRB120711A
  46. GRB 120711A: ROTSE-III confirm of Optical Counterpart
  47. Skynet/PROMPT Observations of GRB120711A
  48. GRB 120709A: Swift-XRT observations
  49. GRB 120709A: optical afterglow limits
  50. GRB 120624B: mm detection at PdBI
  51. GRB 120703A: SMARTS optical/IR observations
  52. GRB 120703A: Swift/UVOT Detection
  53. GRB 120703A: NOT optical observation
  54. GRB 120701A: Swift/UVOT Detection
  55. GRB 120701A: GROND detection of the afterglow
  56. GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis
  57. GRB 120630A: NOT optical source within the XRT error circle
  58. GRB120624B: Chandra observations and afterglow detection
  59. GRB 120624B Further Swift-XRT analysis
  60. GRB 120624B: Swift/UVOT Upper Limits
  61. Watcher follow-up observations of IGR J17062-6143 (Swift trigger 525148)
  62. GRB 120624B: Further analysis of the HAWKI observations
  63. GRB 120624B: Swift-XRT observations
  64. GRB 120624B: GROND upper limits
  65. GRB 120624B: NIR counterpart candidate from HAWKI
  66. Skynet/PROMPT observations of IGR J17062-6143 (Swift trigger 525148)
  67. GRB 120624B: Discussion of Fermi and Swift measurements and future Swift observations
  68. GRB 120624B: NOT optical upper limit
  69. GRB 120624B: optical observations
  70. Swift Trigger 524949: Noise fluctuation near a galaxy
  71. GRB 120622A: MAXI/GSC detection
  72. GRB 120614A: MAXI/GSC detection of a burst
  73. GRB 120612A: optical observations
  74. GRB 120612A: Swift/UVOT observations
  75. GRB 120528C: MAXI/GSC detection
  76. GRB 120521C redshift estimate
  77. GRB 120528B: MAXI/GSC detection
  78. GRB 120521C: EVLA 22 GHz Detection
  79. GRB120521B: SSO 2.3m upper limits
  80. GRB 120521A: ATCA 34GHz upper limit
  81. GRB 120521C: Early Tautenburg limits
  82. GRB 120521A: GROND Upper limits
  83. GRB 120521C: Keck Observations
  84. GRB 120521C: Swift/UVOT Upper Limits
  85. GRB 120521B: Swift/UVOT Upper Limits
  86. GRB 120521B: GROND Upper limits
  87. GRB 120521C: PAIRITEL NIR Upper Limits
  88. GRB 120521C: BOOTES-1 optical observations
  89. GRB 120521C: WHT optical observations
  90. GRB120521C: Liverpool Telescope observations
  91. GRB 120521C: TAROT Calern observatory optical observations
  92. Swift starts a new program to find fainter transients
  93. GRB 120521A: Swift/UVOT Upper Limits
  94. Correction to GCN 13307 (GRB120521B)
  95. GRB120521B: Faulkes Telescope South observations
  96. GRB 120521B: TAROT La Silla observatory optical observations
  97. GRB 120521A: TAROT La Silla observatory optical observations
  98. GRB 120514A: Swift/UVOT Upper Limits
  99. GRB 120514A: UKIRT IR observations
  100. GRB 120514A: APEX observations of the submm counterpart

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