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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"

28082 results found.

  1. GRB110530A: MITSuME Okayama Optical Observation
  2. GRB 110530A: Swift-BAT refined analysis
  3. GRB 110529A: Fermi GBM detection
  4. GRB 110530A: Swift detection of a burst with an optical afterglow
  5. LAT Observations of GRB110529A
  6. EVLA afterglow limits on the high z GRB090429B
  7. Swift J1644+57/GRB 110328A, Additional HST Observations
  8. GRB 110521A: MASTER prompt optical limit
  9. GRB 110521A: Swift/UVOT Upper Limits
  10. GRB 110521A: Swift-XRT refined analysis
  11. GRB 110520A: NOT optical follow-ups
  12. GRB 110521A - NOT optical observation
  13. GRB 110521A: Swift-BAT refined analysis
  14. GRB 110521A: Enhanced Swift-XRT position
  15. GRB 110521A: MASTER synchronous and early optical observations limit
  16. Swift/UVOT observations of GRB110520A
  17. GRB 110521A: Swift detection of a burst
  18. GRB 110520A: Swift-BAT refined analysis
  19. GRB 110520A: IAC80 I-band observations
  20. GRB 110520A: Swift-XRT refined Analysis
  21. GRB 110520A: Enhanced Swift-XRT position
  22. GRB 110520A: WHT IR observations
  23. GRB 110520A - NOT optical observation
  24. GRB 110520A: TAROT Calern observatory optical observations
  25. GRB 110520A: Swift detection of a burst
  26. IPN localization of bright GRB 110518A
  27. GRB 110519A, Swift-BAT refined analysis
  28. GRB 110519A: Swift detection of a burst
  29. GRB 110426A: Fermi GBM detection
  30. GRB 110428A: Fermi-GBM observation
  31. GRB 110503A: TAROT Calern observatory optical observations
  32. Konus-Wind observation of GRB 110503A
  33. GRB 110503A: optical observation in CrAO
  34. GRB 110503A: Centimeter observation from EVLA
  35. GRB 110503A: Millimeter observation from SMA
  36. GRB 110503A: SARA-N Observations and Photometric Calibration
  37. GRB 110503A: Swift/UVOT Observations
  38. GRB 110503A: Swift-XRT refined Analysis
  39. GRB 110503A: PAIRITEL NIR Detection
  40. GRB 110503A: Swift-BAT refined analysis
  41. GRB 110503A: Enhanced Swift-XRT position
  42. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  43. GRB 110426A: Swift/XRT non-detection
  44. GRB 110428A : X-ray afterglow confirmation
  45. GRB 110428A: Suzaku WAM observation of the prompt emission
  46. GRB 110422A: optical observations in CrAO
  47. GRB 110428A : Swift-XRT observations
  48. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  49. GRB 110422A: optical observations in CrAO, second epoch
  50. GRB 110422A: Suzaku WAM observation of the prompt emission
  51. GRB110422A: NOT optical follow-ups
  52. GRB 110422A: optical observations in CrAO
  53. GRB110422A: MITSuME Ishigakijima Optical Observation
  54. GRB 110422A: Further NOT observation
  55. GRB 110422A: Swift/UVOT Detection of optical afterglow
  56. GRB 110422A: Swift-XRT refined Analysis
  57. GRB 110422A: Enhanced Swift-XRT position
  58. GRB 110422A: TNG optical observations
  59. GRB 110422A: SAO RAS optical observations
  60. GRB 110422A: NOT optical observation
  61. GRB 110422A: Swift-BAT refined analysis
  62. GRB 110422A: Mondy optical observations
  63. GRB 110422A: Swift detection of a burst
  64. GRB 110420B: Swift/UVOT Upper Limits
  65. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  66. GRB 110420B: Swift-XRT afterglow candidate retraction
  67. GRB 110420B, GROND observations
  68. GRB 110420A Swift/UVOT Observations
  69. GRB 110420B: Swift-XRT afterglow candidate
  70. GRB 110420B: Swift-BAT refined analysis
  71. GRB 110420A: Swift-BAT refined analysis
  72. GRB 110420A: Swift-XRT refined Analysis
  73. GRB 110420A: Enhanced Swift-XRT position
  74. GRB 110420A: Swift detection of a burst with optical counterpart
  75. GRB110414A: MITSuME Ishigakijima Optical upper limits
  76. GRB 110414A: GROND upper limits
  77. GRB110414A: MITSuME Okayama Optical upper limits
  78. GRB 110414A: Swift-BAT Refined Analysis
  79. GRB 110414A: Swift/UVOT Upper limits
  80. GRB 110414A: Swift-XRT refined Analysis
  81. GRB 110414A: Enhanced Swift-XRT position
  82. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  83. GRB 110414A : Faulkes Telescope North observations
  84. GRB 110414A: Swift detection of a burst
  85. GRB 110411A: PAIRITEL NIR Upper Limits
  86. GRB 110412A: Swift-BAT refined analysis
  87. GRB 110411A: Swift-XRT refined Analysis
  88. GRB 110411A: Swift/UVOT Upper Limits
  89. GRB 110411A : Xinglong TNT OT candidate
  90. GRB 110411A, Swift-BAT refined analysis
  91. GRB 110411A: Enhanced Swift-XRT position
  92. GRB 110411A: Swift detection of a burst
  93. GRB 110407A: Swift-XRT refined Analysis
  94. GRB 110328A / Swift J164449.3+573451: MASTER pre, prompt and follow-up observations
  95. GRB 110328A / Swift J164449.3+573451: optical observations
  96. GRB 110328A/Swift J164449.3+573451 UVOT Upper Limits
  97. GRB 110406A: Positional coincidence with NGC 404
  98. GRB110407A: UVOT Upper Limits
  99. GRB 110407A: GROND Detection of the Optical Afterglow
  100. GRB 110407A: MITSuME Okayama and Ishigakijima Optical upper limits

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