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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"

5401 results found.

  1. IPN triangulation of GRB 130228A
  2. GRB 130305A: Optical Observations
  3. GRB 130307A: Fermi GBM detection
  4. GRB 130306A: MASTER-Net pre-Swift alert observation
  5. GRB 130305A: RATIR Observations
  6. Trigger 549841: Swift detection of SGR1806-20
  7. GRB 130216B: Swift/XRT observations
  8. GRB 130216A: P200 NIR Observations
  9. GRB 130215A: P200 NIR observations
  10. GRB 130215A: GMG optical observation
  11. GRB 130215A: iTelescope T11 observations
  12. GRB 130215A: CARMA 3mm detection
  13. GRB 130211A: GROND detection of the afterglow
  14. GRB 130211A: Swift detection of a burst
  15. GRB 130131A: optical observation in Mondy observatory
  16. GRB 130131A: Swift-BAT refined analysis
  17. GRB 130102B: MAXI/GSC detection
  18. GRB121212A: NOT optical imaging
  19. GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
  20. GRB 121212A: Swift-BAT refined analysis
  21. GRB 121123A: NOT optical observations
  22. IPN Triangulation of GRB 121118B (long/intense)
  23. GRB 121102A: Swift-XRT refined Analysis
  24. GRB 121031A: Prompt enhanced Swift-XRT position
  25. GRB 121024A: SMARTS optical/IR afterglow observations
  26. GRB 121027A: MASTER early prompt optical limit
  27. GRB 121011A: optical observations
  28. GRB 120921A: Fermi GBM detection of its 1000th GRB
  29. GRB 120909A: Swift detection of a burst
  30. GRB 120907A: NOT optical observations
  31. GRB 120830A: Further Swift Observations
  32. GRB 120811C: optical observations
  33. GRB120804A: Chandra observations and afterglow detection
  34. Swift Trigger 530581: GRB 120811A or a galactic transient
  35. GRB 120803A: optical upper limit
  36. GRB 120804A: MITSuME Okayama Optical upper limits
  37. GRB 120803B: MITSuME Okayama Optical upper limits
  38. GRB 120803A: MITSuME Okayama Optical upper limits
  39. GRB 120803B: MITSuME Akeno Optical upper limits
  40. GRB 120803B: FTN possible afterglow candidate
  41. Swift Trigger 528925 is probably a noise fluctuation
  42. GRB 120724A: optical observation in Maidanak observatory
  43. GRB 120724A: Swift/UVOT Detection of the Optical Afterglow
  44. GRB 120724A: Swift-XRT refined Analysis
  45. GRB 120724A: FTN optical afterglow candidate
  46. GRB 120716A: Swift-XRT detection
  47. GRB 120716A: Optical decay from NOT
  48. GRB 120714B: GROND confirmation of fading afterglow
  49. GRB 120714B: Position Correction and Candidate Optical Afterglow
  50. GRB 120712A: Swift-BAT refined analysis
  51. GRB 120712A: Swift detection of a burst with optical afterglow
  52. Swift detection of GRB 120711B or a new Galactic transient
  53. GRB 120709A: Swift-XRT observations
  54. GRB 120703A: Fermi GBM detection
  55. GRB 120630A: NOT optical source within the XRT error circle
  56. Swift Trigger 525554 is probably not a GRB
  57. GRB 120624B: Fermi GBM detection
  58. Swift trigger 524642 / SwJ1910.2-0546
  59. IPN Triangulation of GRB 120617A (short/intense)
  60. GRB 120603A: Suzaku WAM observation of the prompt emission
  61. GRB 120521C redshift estimate
  62. Konus-Wind observation of GRB 120522A
  63. IPN triangulation of GRB 120522A (long/intense)
  64. GRB 120521C: MASTER optical limit
  65. GRB 120514A: GROND upper limits
  66. GRB 120510A: MAXI/GSC detection of a burst
  67. IPN Triangulation of GRB 120427A
  68. Swift detection of 4U 1630-47
  69. IPN Triangulation of bright GRB 120426A
  70. GRB 120422A: MITSuME Ishigakijima upper limit
  71. GRB 120422A: Swift detection of a burst
  72. GRB 120404A: optical observations in Mondy observatory
  73. GRB 120404A: MASTER OT observations
  74. GRB 120404A: MITSuME Ishigakijima Optical Observation
  75. GRB 120401A: GROND Detection of an optical/NIR afterglow candidate
  76. GRB 120403B: Fermi GBM Observation
  77. GRB 120404A: Faulkes Telescope North afterglow confirmation
  78. GRB 120403A: MASTER follow up observations
  79. GRB 120402A: MASTER follow up observations
  80. GRB 120326A: Bassano Bresciano Observatory - correction for GCN Cir 13178
  81. GRB 120326A: Cima Rest and Bassano Brescia
  82. GRB 120326A: HCT optical observations
  83. GRB 120401A: Prompt enhanced Swift-XRT position
  84. GRB 120326A: Bassano Bresciano Observatory lightcurve analisis
  85. GRB 120326A: MITSuME Ishigakijima Optical Observation at 3 days afterthe burst
  86. GRB 120326A: CARMA 3mm detection
  87. GRB 120328A: MITSuME Ishigakijima Optical Upper Limits
  88. GRB 120326A: MITSuME Ishigakijima Optical Observation at 2 days afterthe burst
  89. GRB 120327A: MITSuME Ishigakijima Optical Upper Limits at 1 day afterthe burst
  90. Swift trigger 518853: MASTER-ICATE possible OT
  91. long/intense GRB 120328B: MASTER follow up observations
  92. GRB 120326A: Bassano Bresciano Observatory further optical observations
  93. GRB 120327A: MITSuME Ishigakijima Optical Observation
  94. GRB 120326A: MITSuME Ishigakijima Optical Observation
  95. GRB 120328A: Swift detection of a burst
  96. GRB 120326A: PAIRITEL NIR Observations
  97. GRB 120327A: CQUEAN grizY Observation
  98. GRB 120326A: LOAO R-band Observations
  99. GRB 120327A: X-shooter redshift
  100. GROND observations of GRB 120327A

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