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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"

4716 results found.

  1. GRB 120326A: CARMA 3mm detection
  2. GRB 120328A: MITSuME Ishigakijima Optical Upper Limits
  3. GRB 120326A: MITSuME Ishigakijima Optical Observation at 2 days afterthe burst
  4. GRB 120327A: MITSuME Ishigakijima Optical Upper Limits at 1 day afterthe burst
  5. Swift trigger 518853: MASTER-ICATE possible OT
  6. long/intense GRB 120328B: MASTER follow up observations
  7. GRB 120326A: Bassano Bresciano Observatory further optical observations
  8. GRB 120327A: MITSuME Ishigakijima Optical Observation
  9. GRB 120326A: MITSuME Ishigakijima Optical Observation
  10. GRB 120328A: Swift detection of a burst
  11. GRB 120326A: PAIRITEL NIR Observations
  12. GRB 120327A: CQUEAN grizY Observation
  13. GRB 120326A: LOAO R-band Observations
  14. GRB 120327A: X-shooter redshift
  15. GROND observations of GRB 120327A
  16. GRB 120327A: Liverpool Telescope Observations
  17. GRB 120326A: optical observation of GMG
  18. GRB 120326A: T17 optical observations
  19. GRB 120326A: CQUEAN grizY Observation
  20. GRB 120323A: MASTER follow up observations
  21. IPN Triangulation of GRB 120323A (short/very intense)
  22. GRB 120324A: CQUEAN rizY Observation
  23. GRB 120320A: MITSuME Okayama Optical upper limits
  24. GRB 120320A , optical observations
  25. GRB 120320A: MASTER optical observations
  26. GRB 120311B: Optical follow-up
  27. GRB 120311A: C88 optical limits
  28. GRB 120312A: MASTER-NET optical observations
  29. GRB 120311B: C88 optical limits
  30. GRB 120311B: MITSuME Okayama Optical upper limits
  31. GRB 120311B: Enhanced Swift-XRT position
  32. GRB 120311B: Swift-XRT observations
  33. GRB 120311B: Swift detection of a burst
  34. GRB 120311A: Swift/UVOT Upper Limits
  35. GRB 120308A : LOAO optical observation
  36. GRB120308A: MITSuME Ishigakijima Optical Upper Limits
  37. GRB 120305A: EVLA deep limit on a radio counterpart
  38. GRB 120305A: MASTER-NET early optical observations
  39. GRB 120211A : LOAO optical observations
  40. GRB 120202A: Swift/XRT and UVOT observations
  41. GRB 120119A : LOAO Optical Observations
  42. GRB 120119A: optical upper limit
  43. GRB 120118B: Faulkes Telescope South observations
  44. AXP 4U 1042+61: Mondy optical observations
  45. AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
  46. Swift detection of an SGR burst from AXP 4U 0142+61
  47. GRB 120106A: Swift-BAT refined analysis
  48. GRB111225A: RAPTOR Early Detection of the Optical Counterpart
  49. GRB 111228A: LOAO Optical Observation
  50. GRB111228A: Further GMG observations
  51. GRB111228A: MITSuME Okayama Optical Observation
  52. GRB 111225A: GRT Optical Observation
  53. GRB 111225A: Swift detection of a burst with an optical counterpart
  54. GRB 111222A: Xinglong TNT observation
  55. GRB 111210A: optical upper limit of Mt. Terskol observatory
  56. GRB111215A: optical upper limit
  57. GRB 111211A: NOT afterglow confirmation
  58. GRB 111210A: Swift detection of a burst
  59. GRB 111209A optical limit by "Pi of the Sky"
  60. GRB 111123A: optical upper limit in CrAO: correction to the GCN circ. 12613
  61. GRB 111123A: optical upper limit in CrAO
  62. XRF 111111A/MAXI J0158-744: MAXI GSC and SSC detection of a soft X-ray transient near SMC
  63. GRB 111109A: Swift/UVOT Photometry
  64. GRB 111109A: Swift-XRT observations
  65. GRB 111107A: GROND observations
  66. GRB 111103A: Fermi GBM observation
  67. GRB 111103B: optical observations from TAU, Ka-Dar
  68. Trigger 506913: MASTER detection of Swift J1922.7-1716 optical counterpart
  69. GRB 111103B: optical observations
  70. GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
  71. Swift-BAT trigger 506884 is not a GRB
  72. GRB 111029A: Faulkes Telescope North observations
  73. GRB 111022A: Swift detection of a burst
  74. GRB 111008A: Gemini optical counterpart
  75. GRB 111005A: Swift detection of a burst
  76. GRB 111003A: Fermi GBM detection
  77. GRB 110924A: Swift detection of a possible burst
  78. GRB110918A: Lick Observations
  79. GRB 110905A: Swift detection of a burst
  80. GRB 110903A: Fermi GBM observation
  81. GRB 110808A: Swift/UVOT Detection
  82. GRB 110808A: Swift detection of a burst with optical counterpart
  83. GRB 110807A: Swift detection of a burst or a posible new SGR
  84. Fermi GBM trigger 334123030 (110804165) is not a GRB
  85. IPN triangulation of GRB110802A (short/hard burst)
  86. GRB 110801A: optical observations in CrAO
  87. GRB110801A: MITSuME Ishigakijima Optical Observation
  88. AXP 4U 0142+61: Fermi GBM detection
  89. AXP 4U 0142+61: Swift-BAT refined analysis
  90. Swift detection of a SGR-like burst from the AXP 4U 0142+61
  91. GRB 110726A: Swift detection of a burst
  92. Fermi Gamma-ray Burst Monitor trigger 332078586 is not a GRB
  93. GRB110709A: upper limits from CAHA 1.23m and OSN 1.5m
  94. GRB 110708A: Swift/XRT afterglow candidate for the INTEGRAL burst
  95. GRB 110705A: Suzaku WAM observation of the prompt emission
  96. Konus-Wind observation of GRB 110705A
  97. GRB 110705A: Fermi GBM detection
  98. GRB 110625A: GROND detection of a source inside the XRT error circle
  99. GRB110530A: MITSuME Okayama Optical Observation
  100. GRB 110503A: R-band Detection

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