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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').
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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"

4716 results found.

  1. GRB 110420A: Swift detection of a burst with optical counterpart
  2. GRB 110328A / Swift J164449.3+573451: MASTER pre, prompt and follow-up observations
  3. GRB 110407A: MASTER optical observations
  4. GRB 110407A: GROND Detection of the Optical Afterglow
  5. Konus-Wind observation of GRB 110406A
  6. GRB 110328A / Swift J164449.3+573451, HST Observations
  7. GRB 110328A: Konkoly observations.
  8. GRB110328A/Swift J164449.3+573451: Fermi LAT Observations
  9. GRB 110328/Swift J164449.3+573451: Fermi observations
  10. GRB 110328A / Swift J164449.3+573451: X-ray analysis and a mini-blazar analogy
  11. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Detection in 2nd Epoch
  12. GRB 110328A / Swift J164449.3+573451: Konkoly observations
  13. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Upper Limits
  14. GRB 110213A, the review of the sky area in plate archives
  15. GRB / X-ray transient 110328A: MITSuME OkayamaOptical upper limits
  16. GRB 110319B Swift-XRT afterglow confirmation
  17. GRB 110319B: Swift-XRT afterglow candidate.
  18. GRB 110319B found in ground analysis of Swift-BAT data
  19. GRB 110315A: RTT150 optical observations
  20. GRB 110315A: MASTER early optical observations
  21. GRB110312A: MITSuME Okayama Optical upper limits
  22. GRB110305A: MITSuME Ishigakijima Optical upper limits
  23. GRB 110223A: optical upper limits
  24. GRB 110223A: Liverpool Telescope observations
  25. GRB 110223A: Swift detection of a burst
  26. GRB 110201A: Subaru/MOIRCS Ks-band photometry
  27. GRB 110128A: Swift/UVOT observations
  28. GRB 110128A: WHT redshifts of nearby field galaxies
  29. GRB 110128A: Enhanced Swift-XRT position
  30. GRB 110128A: Afterglow detection from NOT
  31. GRB 110128A: Swift detection of a burst
  32. GRB 101224A, the review of the sky area in plate archives
  33. GRB 110120A: Fermi GBM detection
  34. GRB 110106B: MASTER optical observations
  35. Trigger 441015 / GRB 101225A: Further NOT optical observation
  36. GRB 101224A - UVOT-enhanced XRT position
  37. GRB 101219B: GROND Detection of the Optical/NIR Afterglow
  38. GRB 101219A: GROND Upper limits
  39. GRB 101219A: Magellan NIR observations
  40. GRB 101023A: miniTAO/ANIR NIR detection
  41. GGRB 101023A: GROND detection of the optical-NIR afterglow
  42. GRB 101008A: optical observations
  43. GRB 100902A: D50 optical limit
  44. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  45. GRB 101008A: Swift-BAT refined analysis
  46. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  47. GRB 101008A: Swift detection of a burst
  48. GRB 100924A: Suzaku WAM observation of the prompt emission
  49. GRB 100924A: Fermi GBM observation
  50. GRB100925A/MAXI J1659-152 MITSuME Ishigakijima and Okayama Optical Observation
  51. GRB 100924A: Swift detection of a burst
  52. GRB 100917A: Swift detection of a burst
  53. GRB 100906A: GRAS-007 optical observations
  54. GRB 100906A: Observations at the Virtual Telescope
  55. GRB 100906A : Faulkes Telescope North optical observations
  56. Optical observations of GRB 100901A
  57. GRB 100902A: GROND observations; afterglow candidate
  58. GRB100902A: Optical upper limits at IAO
  59. GRB10901A: Optical observations at IAO
  60. GRB 100901A: Lightbuckets Optical Observations
  61. GRB 100902A: optical observation at Mt.Terskol
  62. GRB 100901A: optical observation at Mt.Terskol
  63. GRB 100829.9: MASTER Optical Limits
  64. GRB 100814A: Suzaku WAM observation of the prompt emission
  65. Konus-Wind observation of GRB 100814A
  66. GRB 100816A: MASTER Optical Limits
  67. GRB100816A: TNG optical afterglow confirmation.
  68. GRB 100814A: Fermi GBM observation
  69. GRB 100814A: GROND Detection of the Optical/NIR Afterglow
  70. GRB 100814A: Swift UVOT observations of the optical afterglow
  71. GRB 100814A: Swift detection of a burst with an optical afterglow
  72. GRB 100814A: ROTSE-III Detection of Optical Counterpart
  73. Swift-BAT trigger 431582 likely is IGR J17464-2811
  74. GRB100807A: optical observation in CrAO
  75. GRB 100807A: P60 Optical Afterglow Discovery
  76. GRB 100719A: Swift detection of a burst
  77. GRB 100628A: Near-IR sources coincident with the possible X-ray afterglow
  78. GRB 100628A: Chandra observations
  79. GRB 100628A: Swift XRT/UVOT refined analysis
  80. Konus-Wind observation of GRB 100704A
  81. GRB 100704A: Fermi GBM observation
  82. GRB 100704A: Swift detection of a burst
  83. GRB 100615A: Additional Gemini/NIRI observations
  84. GRB 100701B: Fermi GBM detection
  85. GRB 100702A: Swift detection of a short burst
  86. GRB 100213B: Detection of Fading Optical Afterglow
  87. GRB 100628A: Gemini North Observations
  88. GRB 100628A: Swift XRT refined position
  89. GRB 100628A: Magellan near-IR observations
  90. GRB 100628A: Swift XRT detection of a possible X-ray afterglow
  91. GRB 100625A : IRSF/SIRIUS NIR upper limit
  92. GRB 100625A: Gemini candidate afterglow
  93. Konus-Wind observation of GRB 100621A
  94. GRB 100619A: Correction to the Fermi GBM trigger time
  95. GRB 100621A: GROND observation of bright NIR afterglow
  96. GRB 100621A: ROTSE-III Optical Limits
  97. GRB 100621A: Swift detection of a burst
  98. GRB 100619A: Fermi GBM detection
  99. XRF 100616a : MAXI/GSC detection of a probable XRF
  100. GRB 100615A: Swift detection of a burst

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