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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"

2724 results found.

  1. GRB 150210A: MASTER SN detection during LAT error box inspection
  2. GRB 150204A: GROND observations
  3. GRB 150203A iTelescope observation
  4. GRB 150204A: LCOGT-Sutherland and Siding Springs observations
  5. GRB 150202B: Swift XRT/UVOT observations
  6. GRB 150201A: GROND upper limits
  7. Konus-Wind observation of GRB 150127B
  8. GRB 150123A: MASTER inspection
  9. Swift Trigger 628458 likely not astrophysical
  10. Konus-Wind observation of GRB 150118B
  11. GRB 150120B: P60 optical afterglow
  12. Swift detection of 4U 1700+24 (= V* V934 Her)
  13. GRB 141229A: MAXI/GSC detection
  14. GRB 141225A: MASTER-SAAO first OT detection
  15. GRB 141225A: Enhanced Swift-XRT position
  16. GRB 141225A: UVOT detection
  17. GRB 141225A: Optical aftergow confirmation
  18. GRB 141225A: LT optical candidate
  19. GRB 141225A: 1.23m CAHA optical observations
  20. GRB 141225A: Swift detection of a burst
  21. IPN Triangulation of GRB 141222A (very intense)
  22. GRB 141220A: Fermi GBM observation
  23. Swift detection of 4U 1700+24 (= V934 Her)
  24. GRB 141212A: MASTER early optical observations
  25. GRB 141130A: Swift/UVOT Detection
  26. GRB 141130A: Swift detection of a burst with an optical counterpart
  27. GRB 141121A: MITSuME Akeno Optical observation
  28. GRB 141121A: MAXI/GSC detection
  29. GRB 141109A: Swift-BAT refined analysis
  30. GRB 141109A: CQUEAN Detection at 0.85 - 1.05 micron
  31. GRB 141109B: Swift detection of a burst
  32. GRB 141104A: Swift-XRT observations
  33. GRB 141028A: TShAO optical observation
  34. GRB 141031B: Nanshan optical upper limit
  35. Konus-Wind observation of GRB 141017A
  36. Swift detection of outburst from 4U 1700+24
  37. GRB 140916B: iPTF Optical Observations
  38. GRB 140916A: Swift detection of a burst
  39. Fermi GBM trigger 140913075 is not a GRB
  40. GRB 140907A: T100 observations
  41. GRB 140906B: Fermi GBM Detection of a Long GRB
  42. IPN triangulation of GRB 140810A
  43. Konus-Wind observation of GRB 140810A
  44. Swift trigger 609139 is probably 4U 1850-03
  45. GRB 140723A: MASTER optical observation
  46. IPN Triangulation of GRB 140721A
  47. GRB 140716A: GROND confirmation of the afterglow
  48. GRB 140713A : Xinglong TNT upper limit
  49. GRB 140703A: MASTER optical observations
  50. GRB 140703A: BOOTES-2 and OSN optical observations
  51. Fermi 425667201: optical counterpart search
  52. GRB 140629A: KWFC z-band photometry
  53. GRB 140628A: Swift-XRT refined Analysis
  54. GRB 140620A / iPTF14cva: TShAO optical observations
  55. GRB 140620A: Swift/UVOT Detection
  56. GRB 140619B: Fermi-LAT Detection
  57. GRB 140614B: MITSuME Akeno upper limits
  58. Fermi 423717114: Additional P48 and P60 observations
  59. Konus-Wind observation of GRB 140528A
  60. IPN Triangulation of GRB 140528A
  61. Swift detection of SFXT IGR J17544-2619
  62. Swift trigger 599860 probably not real
  63. GRB 140515B: MAXI/GSC detection
  64. GRB 140515A: MITSuME Akeno upper limits
  65. Konus-Wind observation of GRB 140508A
  66. GRB 140508A: SAO RAS and MASTER photometric and spectroscopic observations
  67. GRB 140502A: MITSuME Okayama upper limits
  68. GRB 140419A: MITSuME Okayama Optical Observation
  69. Swift Trigger 595345 is not an astrophysical source
  70. GRB 140408A: MITSuME Okayama upper limits
  71. IPN Triangulation of GRB 140329A
  72. GRB 140320D: Suzaku WAM observation of the prompt emission
  73. GRB 140320A: Enhanced Swift-XRT position
  74. GRB 140320A: Swift-XRT detection of an afterglow candidate
  75. GRB 140320B: Xinglong TNT upper limit
  76. GRB 140311C: MASTER before, during and after trigger optical observations
  77. IPN Triangulation of GRB 140306A
  78. GRB 140219A: Suzaku WAM observation of the prompt emission
  79. GRB 140219A: MASTER before and after GRB observational arguments of the exceptionally Dark GRB
  80. GRB 140221A: MAXI/GSC detection
  81. GRB 140215A: Swift/UVOT Detection
  82. GRB 140215A: Swift-BAT refined analysis
  83. GRB 140215A: ISON-NM optical observations
  84. GRB 140215A: T24 optical observations
  85. GRB 140215A: Enhanced Swift-XRT position
  86. GRB 140215A: Swift detection of a burst with optical counterpart
  87. GRB 140209A: optical observations
  88. GRB 140129B: Swift/UVOT Detection
  89. GRB 140129B: MASTER OT early light curve
  90. GRB 140129B: Swift detection of a burst with an optical afterglow
  91. Fermi412093190: iPTF optical counterpart search
  92. GRB 140103A: AAO optical afterglow candidate
  93. GRB 140108A: MASTER-Net OT detection
  94. GRB 140105A/Fermi410578384: MASTER-Net early optical observations
  95. GRB140104A : Xinglong TNT observation. A bright star is located nearby
  96. GRB 140102A: Fermi/GBM Observation
  97. GRB 140102A: MAXI/GSC detection
  98. GRB 140102A: Swift-XRT refined Analysis
  99. GRB 140102A: Fermi-LAT detection of a burst
  100. Konus-Wind observation of GRB 131226A

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