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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"

23417 results found.

  1. GRB 120308A: IAC80 I-band observations
  2. GRB 120308A: PAIRITEL NIR observations
  3. GRB 120308A: confirmation of the optical afterglow
  4. GRB 120308A: Swift detection of a burst
  5. GRB 120305A: D50 optical limits
  6. GRB 120302A: Fermi GBM Observation
  7. GRB 120302A: Swift-BAT refined position and a possible XRT and UVOT counterpart
  8. GRB 120305A: Swift/UVOT Upper Limits
  9. GRB 120305A: EVLA deep limit on a radio counterpart
  10. GRB 120305A: Enhanced Swift-XRT position
  11. GRB 120305A: Swift detection of a short burst
  12. GRB 120302A: GROND detection of an afterglow candidate
  13. GRB 111222A: Swift observation on 2012 February 06/07
  14. GRB 120229A: Swift detection of a short burst
  15. GRB 120226A: Fermi-GBM and Fermi-LAT detections; LAT position retraction
  16. IPN Triangulation of GRB 120226A
  17. GRB 120227A: RAPTOR Limit During the Gamma-Ray Emitting Interval
  18. GRB 120224A: optical observation in Mondy observatory
  19. GRB 120224A: GROND detection of the afterglow candidate
  20. Swift Trigger 516027 is CC Eri
  21. GRB 120224A: Swift/UVOT Upper Limits
  22. GRB 120224A: Swift-BAT refined analysis
  23. GRB 120224A: Enhanced Swift-XRT position
  24. GRB 120224A: Swift detection of a burst
  25. GRB 1202019A: optical observation in Mondy observatory
  26. GRB 120219A: MASTER prompt and early optical limit and OT discussion
  27. GRB 120219A: 1.23m CAHA optical observations
  28. GRB 120219A: Swift/UVOT Upper Limits
  29. GRB 120219A: MITSuME Okayama Optical upper limits
  30. GRB 120219A: Enhanced Swift-XRT position
  31. GRB 120219A: MASTER-NET prompt and early optical observations
  32. GRB 120219A: Swift detection of a burst
  33. GRB 120218A: Swift-BAT refined analysis
  34. GRB 120218A: Swift detection of a burst
  35. GRB 120215A: Swift/UVOT Upper Limits
  36. GRB 120215A: MITSuME Okayama Optical upper limits
  37. Fermi GBM detection of an SGR-like burst
  38. GRB 120215A: Enhanced Swift-XRT position
  39. Skynet/PROMPT observations of GRB120215A
  40. GRB 120215A: Swift-BAT refined analysis
  41. GRB 120215A: Swift detection of a burst
  42. GRB 120213A: Swift/UVOT Upper Limits
  43. GRB 120212A: GMG optical observation
  44. GRB 120213A: Enhanced Swift-XRT position
  45. GRB 120212A: MITSuME Ishigakijima Optical Observation
  46. GRB 120213A: Swift detection of a burst
  47. GRB 120212A: NOT optical observation
  48. GRB 120212A: Swift/UVOT Detection
  49. GRB 120212A: Enhanced Swift-XRT position
  50. GRB 120211A: MITSuME Okayama Ks-band Observation
  51. GRB 120212A: Swift-XRT observations
  52. GRB 120211A: GROND Upper limits
  53. GRB 120212A: Swift detection of a burst
  54. GRB 120211A: MITSuME Okayama and Ishigakijima Optical upper limits
  55. GRB 120211A: Swift/UVOT Upper Limits
  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: Swift detection of a burst
  60. GRB 120202A: D50 optical limits
  61. Swift detection of a burst from LS I +61 303
  62. GRB 120202A: GROND observations
  63. GRB 120202A: WHT, Gemini & UKIRT candidate afterglow
  64. GRB 120202A: Swift/XRT and UVOT observations
  65. GRB 120202A: TAROT Calern observatory optical observations
  66. IPN Triangulation of GRB 120129A (long/intense)
  67. GRB 120127A / P48 Imaging
  68. GRB 120118B: optical upper limit
  69. GRB 120116A: optical upper limit
  70. GRB 120119A : LOAO Optical Observations
  71. GRB 120119A : SMA submm follow-up observation
  72. GRB 120119A: GRT detection of early afterglow
  73. GRB 111225A: optical observations
  74. GRB 120119A: optical upper limit
  75. GRB 120121A: Swift/UVOT Upper Limits
  76. GRB 120121A: Enhanced Swift-XRT position
  77. GRB 120121A: ISON-NM optical observations
  78. GRB 120121A: Swift detection of a burst
  79. GRB 120119A: TAROT La Silla observatory optical observations
  80. GRB120119A: REM NIR observations
  81. GRB 120119A: optical observations
  82. GRB 120119A: Swift/UVOT Observations
  83. GRB 120118B: RTT150 optical observations
  84. GRB 120119A: SMARTS optical/IR afterglow observations
  85. GRB 120119A: Enhanced Swift-XRT position
  86. GRB 120119A: optical observations
  87. GRB 120118B: TNG NIR observations
  88. GRB 120118B : Lulin Optical limit
  89. GRB 120119A: PROMPT optical observation of early afterglow
  90. GRB 120119A: GROND Detection of the Optical/NIR Afterglow
  91. GRB 120118B: Swift/UVOT Upper Limits
  92. GRB 120119A: PAIRITEL NIR Detection
  93. GRB 120119A: Swift detection of a burst with an optical counterpart
  94. GRB 120118B: NOT observations
  95. GRB 120118B: Enhanced Swift-XRT position
  96. XRF 120118A: early optical limit by "Pi of the Sky"
  97. GRB 120118B: Swift detection of a burst
  98. XRF 120118A: Optical candidate
  99. GRB 120116A: Swift/UVOT Upper Limits
  100. GRB 120116A: Enhanced Swift-XRT position

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