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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"

5060 results found.

  1. GRB 160409A found in Swift BAT ground analysis
  2. GRB 160410A: Swift/UVOT Detection
  3. GRB 160410A: Swift detection of a (possibly-short) burst with an optical counterpart
  4. LIGO/Virgo G211117: LOFAR follow-up
  5. GRB 160327A: JCMT SCUBA-2 sub-mm observation
  6. GRB 160327A: Continued RATIR Optical and NIR Observations
  7. GRB 160327A: Mondy optical upper limit
  8. GRB 160327A: RATIR Optical and NIR Afterglow Detection
  9. GRB 160325A: GROND Upper Limits
  10. GRB 160325A: Swift detection of a burst
  11. Swift detects GX 301-2 in very high state
  12. GRB 160321A: AbAO optical observations
  13. GRB 160321A: Possible RATIR Optical and NIR Detections
  14. GRB 160321A: MASTER observations zero Galaxy latitude GRB
  15. GRB 160310A: Terskol 2-m observations
  16. GRB 160310A: A further Swift-XRT observation, no afterglow detected
  17. GRB 160314A: Continued RATIR Optical and NIR Observations
  18. GRB 160313A: Mondy optical upper limit
  19. GRB 160314A: GROND optical/NIR observations
  20. GRB 160314A: ISON-Ussuriysk optical upper limit, updated photometry and correction of GCN 19184
  21. GRB 160314A: RATIR Optical and NIR Observations
  22. GRB 160314A: Mondy optical observations
  23. GRB 160228A: GROND afterglow confirmation and X-shooter host candidate redshift
  24. GRB 160314A: ISON-Ussuriysk optical upper limit
  25. GRB 160314A: Weihai optical upper limit
  26. GRB 160314A: Swift detection of a burst
  27. GRB 160313A: MASTER-Net optical observations
  28. GRB 160313A: RATIR Optical and NIR Observations
  29. GRB 160310A: MASTER-Kislovods observations
  30. GRB 160310A: Further NOT observations
  31. GRB 160310A: RATIR Optical and NIR Observations
  32. GRB 160310A: NOT optical observations
  33. GRB 160310A: LCOGT-SAAO optical upper limits
  34. LIGO/Virgo G211117: HAWC follow-up of northern sky
  35. GRB 160303A: X-shooter spectroscopy
  36. GRB 160303A: JCMT SCUBA-2 sub-mm observation
  37. GRB160303A: further GROND observations
  38. GRB 160303A: Continued RATIR Optical and NIR Observations
  39. GRB 160303A: GROND Optical Detection
  40. GRB 160303A: VLT/FORS2 afterglow obervations
  41. GRB 160303A: McDonald 2.1m CQUEAN Detection
  42. GRB 160303A: RATIR Optical and NIR Afterglow Detection
  43. GRB 160303A: MITSuME Akeno optical upper limits
  44. GRB 160303A: LCOGT-FTN optical observations
  45. GRB 160303A: MITSuME Okayama upper limits
  46. GRB 160303A: ISON-NM early optical early limits
  47. GRB 160227A: McDonald 0.8m Detection
  48. GRB 160227A: MASTER prompt OT Detection and LC
  49. GRB 160227A: MASTER OT Detection
  50. Fermi GBM trigger 477460274/160218161 is not a GRB
  51. GRB 160223A: GROND optical/NIR afterglow
  52. LIGO/Virgo G211117: LOFAR follow-up
  53. GRB 160203A: MITSuME Akeno optical upper limits
  54. GRB 160203A: TSHAO optical observations
  55. GRB 160203A: Skynet PROMPT-CTIO observations of the optical afterglow
  56. The bright GRB160203A: X-shooter spectroscopy and redshift
  57. GRB 160203A: LCOGT-Cerro Tololo optical afterglow confirmation
  58. GRB 160203A: GROND Afterglow Candidate
  59. GRB 160131A: RATIR Optical Observations
  60. GRB 160131A: LCOGT-FTN optical afterglow observations
  61. GRB 160127A: VLA Detection
  62. GRB 160127A: Swift/UVOT Detection
  63. GRB 160127A: Swift detection of a burst with an optical counterpart
  64. GRB160119A: BOOTES-2/TELMA Early Upper Limits
  65. LIGO/Virgo G184098: MASTER final result
  66. GRB 160117B: Early iTelescope observation
  67. GRB 160119A: Swift detection of a burst
  68. GRB 160117B: VLT/X-shooter spectroscopy
  69. LIGO/Virgo G211117: Preliminary VLA observation summary of PS15dpn
  70. IPN Triangulation of GRB 160113A
  71. LIGO/Virgo G211117: Further Swift-XRT sources
  72. LIGO/Virgo G211117: Swift observations of PS15dpn
  73. LIGO/Virgo G211117: VISTA imaging
  74. GRB 160104A: Continued MITSuME Akeno Optical Observation
  75. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  76. GRB 160107A: MAXI/GSC detection
  77. IPN Triangulation of GRB 151225A (short/hard)
  78. LIGO/Virgo G211117: Further Swift-XRT sources
  79. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  80. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  81. GRB 160104B: MAXI/GSC detection
  82. LIGO/Virgo G211117: LOFAR follow-up
  83. LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
  84. LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
  85. GRB 160102A: MAXI/GSC detection
  86. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  87. LIGO/Virgo G211117: MAXI/GSC observations
  88. LIGO/Virgo G211117: LBT Follow-up of iPTF15fen
  89. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  90. LIGO/Virgo G211117: SkyMapper observations and transient candidate
  91. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  92. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  93. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  94. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  95. LIGO/Virgo G211117: Further Swift-XRT sources
  96. GRB 151228A: T60 observations
  97. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  98. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  99. LIGO/Virgo G211117: MASTER Observations and Inspection + OT
  100. LIGO/Virgo G211117: INTEGRAL was inactive at the time of the event

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