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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"
  1. GRB_120215, the_review_of_the_sky_area_in_plate_archives
  2. GRB 1202019A: optical observation in Mondy observatory
  3. GRB 120219A: MASTER prompt and early optical limit and OT discussion
  4. GRB 120219A: 1.23m CAHA optical observations
  5. GCN 12974 : Errata in the Subject
  6. GRB 120219A, optical observations
  7. GRB120219A: Keck Observations
  8. GRB 120215A: MITSuME Akeno Optical upper limits
  9. GRB 120219A: Swift-XRT refined Analysis
  10. GRB 120219A: Swift/UVOT Upper Limits
  11. GRB 120219A: MITSuME Okayama Optical upper limits
  12. GRB 120219A: Swift-BAT refined analysis
  13. GRB 120219A: Enhanced Swift-XRT position
  14. GRB120219A: TNT optical afterglow candidates
  15. GRB 120219A: MASTER-NET prompt and early optical observations
  16. GRB 120219A: Swift detection of a burst
  17. GRB 120218A: Swift-BAT refined analysis
  18. GRB 120218A: Swift detection of a burst
  19. GRB 120215A: Swift/UVOT Upper Limits
  20. GRB 120215A: MITSuME Okayama Optical upper limits
  21. GRB 120215A: Swift-XRT refined Analysis
  22. Fermi GBM detection of an SGR-like burst
  23. GRB 120215A: Enhanced Swift-XRT position
  24. Skynet/PROMPT observations of GRB120215A
  25. GRB 120215A: Swift-BAT refined analysis
  26. GRB 120215A: Swift detection of a burst
  27. GRB 120211A : LOAO optical observations
  28. GRB 120213A: Swift-XRT refined Analysis
  29. GRB 120213A: Swift/UVOT Upper Limits
  30. GRB 120212A: Fermi GBM observation
  31. GRB 120212A: GMG optical observation
  32. GRB 120213A: Enhanced Swift-XRT position
  33. GRB 120212A: MITSuME Ishigakijima Optical Observation
  34. GRB 120213A: Swift-BAT refined analysis
  35. GRB 120213A: MASTER-NET early optical observations
  36. GRB 120213A: Prompt enhanced Swift-XRT position
  37. GRB 120212A: Swift-XRT refined Analysis
  38. GRB 120213A: Swift detection of a burst
  39. GRB 120212A: NOT optical observation
  40. GRB 120212A: Swift/UVOT Detection
  41. GRB 120212A: Swift-BAT refined analysis
  42. GRB 120212A: Errata of subject in GCNC 12936
  43. GRB 120212A: Enhanced Swift-XRT position
  44. GRB 120211A: MITSuME Okayama Ks-band Observation
  45. GRB 120212A: Kanata/HOWPol optical observation
  46. GRB 120212A: Swift-XRT observations
  47. GRB 120212A: Swift/UVOT detection
  48. GRB 120212A: Faulkes Telescope South afterglow candidate
  49. GRB 120211A: GROND Upper limits
  50. GRB 120212A: Swift detection of a burst
  51. GRB 120211A: MITSuME Okayama and Ishigakijima Optical upper limits
  52. GRB 120211A, optical observations
  53. GRB 120211A: Swift-XRT refined Analysis
  54. GRB 120211A: Swift/UVOT Upper Limits
  55. GRB 120211A: MASTER early optical observations
  56. GRB 120211A: Swift-BAT refined analysis
  57. GRB 120211A: MITSuME Okayama Ks-band upper limit
  58. GRB 120211A: Enhanced Swift-XRT position
  59. GRB 120211A - Faulkes Telescope South Observations
  60. GRB 120211A: Swift detection of a burst
  61. GRB 120202A, the review of the sky area in plate archives
  62. GRB 111228A, the review of the sky area in plate archives
  63. GRB 120202A: MASTER early optical observations
  64. LS I +61 303: Swift-BAT refined analysis
  65. GRB 120202A: D50 optical limits
  66. Swift detection of a burst from LS I +61 303
  67. GRB 120202A: GROND observations
  68. GRB 120202A: WHT, Gemini & UKIRT candidate afterglow
  69. GRB 120202A: Swift/XRT and UVOT observations
  70. GRB 120202A: TAROT Calern observatory optical observations
  71. GRB 120202A: A long GRB detected by INTEGRAL
  72. GRB 111228A: Possible host detected by Swift/UVOT
  73. GRB 120129A: MASTER optical observations
  74. GRB 120116A, the review of the sky area in plate archives
  75. Konus-Wind observation of GRB 120129A
  76. IPN Triangulation of GRB 120129A (long/intense)
  77. GRB 120127A / P48 Imaging
  78. GRB 120127A: MASTER optical observations
  79. GRB 120127A: MAXI/GSC detection of a probable GRB
  80. GRB 120118B: optical upper limit
  81. GRB 120116A: optical upper limit
  82. GRB 120119A : LOAO Optical Observations
  83. GRB 120119A : SMA submm follow-up observation
  84. Fermi GBM trigger 120123.169 is not a GRB
  85. GRB 120119A: EVLA observations
  86. GRB 120119A: GRT detection of early afterglow
  87. GRB 111225A: optical observations
  88. GRB 120119A: optical upper limit
  89. GRB 120121A: Swift/UVOT Upper Limits
  90. GRB 120121A: Swift-XRT refined Analysis
  91. GRB 120121A: Swift-BAT refined analysis
  92. GRB 120121A: Enhanced Swift-XRT position
  93. GRB 120121A: ISON-NM optical observations
  94. GRB 120121A: Swift-XRT position
  95. GRB 120121A: Swift detection of a burst
  96. GRB 120119A, Swift-BAT refined analysis
  97. GRB 120119A: TAROT La Silla observatory optical observations
  98. GRB120119A: REM NIR observations
  99. GRB 120119A: optical observations
  100. GRB 120119A: Swift/UVOT Observations

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