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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"

45475 results found.

  1. GRB120404A: MOA optical observations of the initial rise afterglow
  2. GRB 120404A: VLT/X-shooter redshift confirmation
  3. GRB 120404A: Swift/UVOT Detection
  4. GRB 120404A: MITSuME Ishigakijima Optical Observation
  5. GRB 120404A: MITSuME Okayama Optical Observation
  6. GRB 120403B: Swift-XRT refined Analysis
  7. GRB 120404A: Swift-XRT refined Analysis
  8. GRB 120404A : TNT optical observation
  9. GRB 120404A: Swift-BAT refined analysis
  10. GRB 120401A: GROND Detection of an optical/NIR afterglow candidate
  11. GRB 120404A: Enhanced Swift-XRT position
  12. GRB 120404A: Gemini-N Redshift correction
  13. GRB 120402B: MASTER early OT limit
  14. GRB 120403B: TAROT La Silla observatory optical observations
  15. GRB 120403B: Fermi GBM Observation
  16. GRB 120404A: Gemini-N Redshift
  17. GRB 120403B: AAT nIR observations
  18. GRB 120404A: MITSuME Akeno Optical upper limits
  19. GRB 120404A: MASTER early OT limit
  20. GRB 120404A: Faulkes Telescope North afterglow confirmation
  21. GRB 120404A: Swift detection of a burst with an optical counterpart
  22. GRB 120403B: Swift-BAT refined analysis
  23. GRB 120403B: Swift/UVOT Upper Limits
  24. GRB 120403B: Enhanced Swift-XRT position
  25. GRB 120403A: Swift/BAT spectral lag analysis
  26. GRB 120403B: Swift detection of a burst
  27. BAT trigger 519207 was a burst from Cyg X-1, was not GRB 120402A
  28. GRB 120326A, the review of the sky area in plate archives
  29. GRB 120402A: optical upper limit
  30. GRB 120320A: optical upper limit in Mondy observatory
  31. GRB 120320A: early optical upper limit
  32. GRB 120403A: MASTER follow up observations
  33. GRB 120402A: MASTER follow up observations
  34. GRB 120403A, Swift-BAT refined analysis
  35. GRB 120402B: Fermi GBM detection
  36. GRB 120328B: Pi of the Sky simultaneous upper limits
  37. GRB 120326A: Bassano Bresciano Observatory - correction for GCN Cir 13178
  38. GRB 120403A: Swift detection of a burst
  39. GRB 120402A: Swift detection of a possible burst or noise
  40. GRB 120326A: Cima Rest and Bassano Brescia
  41. GRB 120327A: SMARTS optical/IR afterglow observations
  42. GRB 120401A: Swift-XRT refined Analysis
  43. GRB 120401A: Swift-BAT refined analysis
  44. GRB 120326A: HCT optical observations
  45. GRB 120401A: Enhanced Swift-XRT position
  46. GRB 120401A: Prompt enhanced Swift-XRT position
  47. GRB 120401A: Swift detection of a burst
  48. GRB 120326A: EVLA Observations
  49. GRB120327A - ATCA radio afterglow detection at 34GHz
  50. GRB 120324A: CrAO optical upper limit
  51. GRB 120326A: Bassano Bresciano Observatory lightcurve analisis
  52. GRB 120326A: MITSuME Ishigakijima Optical Observation at 3 days afterthe burst
  53. GRB 120326A : Suzaku WAM observation of the prompt emission
  54. GRB 120326A: CARMA 3mm detection
  55. GRB 120324A, the review of the sky area in plate archives
  56. Swift trigger 518853 is most likely GX 301-2
  57. GRB 120326A: Bassano Bresciano Observatory optical observations
  58. GRB 120328A: MITSuME Ishigakijima Optical Upper Limits
  59. GRB 120326A: MITSuME Ishigakijima Optical Observation at 2 days afterthe burst
  60. GRB 120327A: MITSuME Ishigakijima Optical Upper Limits at 1 day afterthe burst
  61. Swift trigger 518853: MASTER-ICATE possible OT
  62. The Swift-XRT source associated with trigger 518853 is a cosmic ray
  63. Trigger 518853: Swift detection of a probable Galactic transient
  64. GRB 120328B: Fermi-LAT Observations
  65. GRB 120327A: Zadko optical observations
  66. GRB 120328B: Fermi GBM detection
  67. long/intense GRB 120328B: MASTER follow up observations
  68. GRB 120328A: Swift/UVOT Upper Limits
  69. GRB 120326A: Bassano Bresciano Observatory further optical observations
  70. GRB 120328A: Swift-XRT refined Analysis
  71. Konus-Wind observation of GRB 120328B
  72. IPN Triangulation of GRB 120328B (long/intense)
  73. GRB 120327A: MITSuME Ishigakijima Optical Observation
  74. GRB 120326A: MITSuME Ishigakijima Optical Observation
  75. GRB 120328A: Swift-BAT refined analysis
  76. GRB 120328A: Enhanced Swift-XRT position
  77. GRB 120327A: NOT optical observations
  78. GRB 120328A: TAROT La Silla observatory optical observations
  79. GRB 120326A: Xinglong TNT further optical observation��correction for GCN Cir 13149)
  80. GRB 120326A: Xinglong TNT further optical observation
  81. Skynet/PROMPT observations of GRB120328A
  82. GRB 120328A: Swift detection of a burst
  83. GRB 120327A: GTC redshift confirmation
  84. GRB 120326A: Fermi GBM Observation
  85. GRB 120327A afterglow detection
  86. GRB 120326A: PAIRITEL NIR Observations
  87. GRB 120326A: Bassano Bresciano Observatory optical observations
  88. GRB 120327A: Swift-XRT refined Analysis
  89. GRB 120327A: CQUEAN grizY Observation
  90. GRB 120326A: LOAO R-band Observations
  91. GRB 120327A: Swift/UVOT further analysis
  92. GRB 120327A: Swift-BAT refined analysis
  93. GRB 120326A : SMA submm observation
  94. GRB 120327A: Enhanced Swift-XRT position
  95. GRB 120327A: X-shooter redshift
  96. GRB 120327A: Gemini-South redshift
  97. GRB 120327A: TAROT La Silla observatory optical decay
  98. GRB120326A: TNT optical observation
  99. GRB 120327A: IAC80 I-band observations
  100. GROND observations of GRB 120327A

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