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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"

28087 results found.

  1. GRB 120308A: confirmation of the optical afterglow
  2. GRB 120308A: Swift detection of a burst
  3. GRB 120305A: D50 optical limits
  4. GRB 120305A: Swift spectral lag analysis
  5. GRB 120302A, the review of the sky area in plate archives
  6. GRB 120302A: Swift-BAT refined position and a possible XRT and UVOT counterpart
  7. GRB 120305A: Swift/UVOT Upper Limits
  8. GRB 120305A: Swift-XRT refined Analysis
  9. GRB 120305A: Enhanced Swift-XRT position
  10. GRB 120305A: Swift-BAT refined analysis
  11. GRB 120305A: Swift detection of a short burst
  12. GRB 120302A: GROND detection of an afterglow candidate
  13. GRB 120302A, Swift-BAT refined analysis
  14. GRB 111222A: Swift observation on 2012 February 06/07
  15. GRB 120229A, Swift-BAT refined analysis
  16. GRB 120226A: Fermi-GBM and Fermi-LAT detections; LAT position retraction
  17. IPN Triangulation of GRB 120226A
  18. GRB 120227A: RAPTOR Limit During the Gamma-Ray Emitting Interval
  19. GRB 120224A: optical observation in Mondy observatory
  20. GRB 120224A: GROND detection of the afterglow candidate
  21. GRB 120219A, the review of the sky area in plate archives
  22. GRB 120224A: Swift-XRT refined Analysis
  23. Swift Trigger 516027 is CC Eri
  24. GRB 120224A: Swift/UVOT Upper Limits
  25. GRB 120224A: Swift-BAT refined analysis
  26. GRB 120224A: Enhanced Swift-XRT position
  27. GRB 120224A: Swift detection of a burst
  28. GRB_120215, the_review_of_the_sky_area_in_plate_archives
  29. GRB 1202019A: optical observation in Mondy observatory
  30. GRB 120219A: MASTER prompt and early optical limit and OT discussion
  31. GRB 120219A: 1.23m CAHA optical observations
  32. GRB 120219A: Swift-XRT refined Analysis
  33. GRB 120219A: Swift/UVOT Upper Limits
  34. GRB 120219A: MITSuME Okayama Optical upper limits
  35. GRB 120219A: Swift-BAT refined analysis
  36. GRB 120219A: Enhanced Swift-XRT position
  37. GRB120219A: TNT optical afterglow candidates
  38. GRB 120219A: MASTER-NET prompt and early optical observations
  39. GRB 120219A: Swift detection of a burst
  40. GRB 120218A: Swift-BAT refined analysis
  41. GRB 120215A: Swift/UVOT Upper Limits
  42. GRB 120215A: MITSuME Okayama Optical upper limits
  43. GRB 120215A: Swift-XRT refined Analysis
  44. Fermi GBM detection of an SGR-like burst
  45. GRB 120215A: Enhanced Swift-XRT position
  46. Skynet/PROMPT observations of GRB120215A
  47. GRB 120215A: Swift-BAT refined analysis
  48. GRB 120215A: Swift detection of a burst
  49. GRB 120211A : LOAO optical observations
  50. GRB 120213A: Swift-XRT refined Analysis
  51. GRB 120213A: Swift/UVOT Upper Limits
  52. GRB 120212A: GMG optical observation
  53. GRB 120213A: Enhanced Swift-XRT position
  54. GRB 120212A: MITSuME Ishigakijima Optical Observation
  55. GRB 120213A: Swift-BAT refined analysis
  56. GRB 120212A: Swift-XRT refined Analysis
  57. GRB 120213A: Swift detection of a burst
  58. GRB 120212A: NOT optical observation
  59. GRB 120212A: Swift/UVOT Detection
  60. GRB 120212A: Swift-BAT refined analysis
  61. GRB 120212A: Enhanced Swift-XRT position
  62. GRB 120211A: MITSuME Okayama Ks-band Observation
  63. GRB 120212A: Swift-XRT observations
  64. GRB 120212A: Swift/UVOT detection
  65. GRB 120212A: Faulkes Telescope South afterglow candidate
  66. GRB 120211A: GROND Upper limits
  67. GRB 120211A: MITSuME Okayama and Ishigakijima Optical upper limits
  68. GRB 120211A: Swift-XRT refined Analysis
  69. GRB 120211A: Swift/UVOT Upper Limits
  70. GRB 120211A: Swift-BAT refined analysis
  71. GRB 120211A: MITSuME Okayama Ks-band upper limit
  72. GRB 120211A: Enhanced Swift-XRT position
  73. GRB 120211A - Faulkes Telescope South Observations
  74. GRB 120211A: Swift detection of a burst
  75. GRB 120202A, the review of the sky area in plate archives
  76. GRB 111228A, the review of the sky area in plate archives
  77. LS I +61 303: Swift-BAT refined analysis
  78. GRB 120202A: D50 optical limits
  79. Swift detection of a burst from LS I +61 303
  80. GRB 120202A: GROND observations
  81. GRB 120202A: WHT, Gemini & UKIRT candidate afterglow
  82. GRB 120202A: Swift/XRT and UVOT observations
  83. GRB 120202A: TAROT Calern observatory optical observations
  84. GRB 120202A: A long GRB detected by INTEGRAL
  85. GRB 120129A: MASTER optical observations
  86. GRB 120116A, the review of the sky area in plate archives
  87. GRB 120127A / P48 Imaging
  88. GRB 120127A: MAXI/GSC detection of a probable GRB
  89. GRB 120118B: optical upper limit
  90. GRB 120116A: optical upper limit
  91. GRB 120119A : LOAO Optical Observations
  92. GRB 120119A : SMA submm follow-up observation
  93. GRB 120119A: GRT detection of early afterglow
  94. GRB 111225A: optical observations
  95. GRB 120119A: optical upper limit
  96. GRB 120121A: Swift/UVOT Upper Limits
  97. GRB 120121A: Swift-XRT refined Analysis
  98. GRB 120121A: Swift-BAT refined analysis
  99. GRB 120121A: Enhanced Swift-XRT position
  100. GRB 120121A: ISON-NM optical observations

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