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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"

20494 results found.

  1. GRB 110918A: Optical light curve for days 1.4 to 16.3
  2. GRB 111018A: GROND Upper Limits
  3. GRB111016A : WIYN 3.5m NIR observations
  4. GRB 111016A: Gemini Detection of the NIR Counterpart
  5. GRB 111016A: Swift/UVOT Detection of a Source
  6. GRB 111016A: P60 Afterglow Candidate
  7. GRB 111016A: Swift-XRT observations
  8. GRB 110921A: optical observations
  9. GRB 111008A : miniTAO/ANIR NIR observations
  10. EVLA 22 GHz Detection of GRB 111008A
  11. GRB 111008A: Swift/UVOT Upper Limits
  12. GRB 111008A: IAC80 I-band observations
  13. GRB 111008A: VLT/X-shooter spectroscopy
  14. GRB 111008A: Gemini spectroscopic redshift
  15. GRB 111008A, GROND observations
  16. GRB 111008A: Gemini optical counterpart
  17. GRB 111005A: ATCA 18 GHz detection
  18. GRB 111005A: ATCA radio upper limit
  19. GRB 111005A : miniTAO/ANIR NIR observations
  20. GRB 111005A: EVLA Observations
  21. GRB 111005A: VLT optical observations
  22. GRB 111005A: GROND NIR observations
  23. GRB 111005A: VLT IR observations
  24. GRB 111005A: bright galaxy in error circle
  25. GRB 110905A / MAXI J1836-194: optical monitoring
  26. Skynet/Dolomiti observations of GRB 110928A
  27. Skynet observations of GRB 110928A
  28. GRB 110928A: RAPTOR Limits During Gamma-ray Emitting Interval
  29. GRB 110928A: Swift/UVOT Upper Limits
  30. GRB 110825A: GROND Observations
  31. GRB 110928A: P60 Observations
  32. GRB 110928A: Further PAIRITEL NIR Observations
  33. GRB 110928A: Swift-XRT observations
  34. GRB 110928A: PAIRITEL NIR Observations
  35. Swift-BAT trigger 503926 is noise
  36. GRB 110921A: Swift/UVOT Observations
  37. GRB110918A: Lick Observations
  38. GRB 110921A: NOT observations
  39. GRB 110918A: Liverpool Telescope optical observations
  40. GRB 110918A: submm observations from APEX
  41. GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
  42. GRB 110921A : TNT optical counterpart candidate
  43. GRB 110921A: MASTER-Net early limit
  44. GRB 110915B : X-ray afterglow confirmation
  45. GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
  46. GRB 110918A optical observation
  47. GRB 110918A: Gemini-N redshift
  48. GRB 110918A: GROND detection of the afterglow candidate
  49. GRB 110918A: Swift-XRT observations
  50. Konus-Wind observation of GRB 110918A
  51. GRB110918A: BOOTES-1 optical limit
  52. GRB 110915B: GROND Observations of the Optical/NIR Afterglow Candidate
  53. GRB 110915A: Swift/UVOT Upper Limits
  54. GRB 110915B: Swift/UVOT Upper Limits
  55. GRB 110915A: GROND Upper limits
  56. GRB 110915A: Deep Near-IR Limits from Magellan
  57. GRB110915A MITSuME Okayama J-band upper-limit
  58. GRB 110915A: NOT observations
  59. GRB 110915A: 1.23m CAHA I-band observations
  60. GRB 110915A: GMG optical upper limit
  61. GRB 110825A: Further Swift/XRT Observations
  62. GRB 110731A: SAO RAS and Terskol observations
  63. GRB 110906A(?): Burst detection (unconfirmed) from Swift-BAT slew data
  64. GRB 110905A / X-ray transient MAXI J1836-194: TNT optical observation
  65. GRB 110905A: Potential BAT trigger on MAXI J1836-194
  66. GRB 110905A: KAIT observations
  67. GRB 110903A: Swift/UVOT Upper Limits
  68. GRB 110903A: Swift-XRT observations
  69. GRB 110825A: GMG optical observation
  70. GRB110825A: Swift target of opportunity observation
  71. Swift-BAT refined analysis of SFXT IGR J08408-4503 (trigger 501368)
  72. GRB 110820A: MASTER-NET first hour observations
  73. GRB 110820A: Swift/UVOT Upper Limits
  74. GRB 110820A: CQUEAN izY Observation
  75. GRB 110820A: MASTER-NET observations
  76. GRB 110818A: Swift/UVOT Upper Limits
  77. GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
  78. GRB 110801A: optical observations at Mt. Terskol observatory
  79. SGR 1834.9-0846/ GRB 110807A, I-band observations
  80. A new photometric resource for GRB observers
  81. SGR 1834.9-0846/ GRB 110807A: archival IR observations
  82. GRB 110808A: Swift/UVOT Detection
  83. Fermi GBM detection of a SGR-like burst
  84. GRB 110807A: SAO RAS observations
  85. GRB 110726A: two epochs of SAO RAS optical observations
  86. GRB 110801A: optical observations in CrAO
  87. EVLA observation for Fermi burst GRB 110721A
  88. GRB110731A: MOA optical observations of the steeply fading afterglow
  89. GRB 110801A: SAO RAS optical observations
  90. GRB 110801A: MASTER OT observations
  91. Swift/UVOT observations of GRB110801A
  92. GRB 110801A: Afterglow redshift from 10.4m GTC
  93. GRB 110801A: ROTSE-III Detection of re-brightening from OT
  94. GRB 110731A / EVLA upper limits
  95. GRB 110731A Gemini-N redshift
  96. GRB110731A: Swift/UVOT Observations
  97. GRB 110731A: NOT photometry
  98. GRB 110731A: FTN+FTS afterglow observations
  99. Sw J1644+57 (GRB 110328A): Continued VLBA Observations
  100. GRB 110721A: Swift observations of afterglow candidate

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