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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"

2797 results found.

  1. GRB 090401B: Swift detection of a burst
  2. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  3. GRB 090401: Swift detection of a burst
  4. GRB090323: Optical observations from NOT
  5. GRB 090328: Possible Swift/XRT detection
  6. GRB 090323: TLS detection at 5 days, no break
  7. GRB 090320B: MASTER-Net prompt optical observations
  8. GRB 090323 TLS detection - still bright
  9. GRB 090323: Possible XRT Counterpart
  10. GRB 090313: VLT spectroscopy
  11. GRB090305B: MASTER-net prompt optical short burst observations
  12. GRB 090306B: Possible XRT afterglow
  13. GRB 090306: Swift detection of a possible burst
  14. GRB 090303: Fermi GBM detection
  15. GRB 081211B: Nearby cluster
  16. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  17. AXP 1E1547.0-5408: Fermi GBM observations
  18. Trigger 340734: Swift detection of a possible short burst
  19. GRB 090118 (BATSS): GRT Optical Observation
  20. GRB 090118: GROND Upper Limits
  21. GRB 090118: Possible burst detection from Swift-BAT slew data
  22. GRB090117: Swift-XRT detection of a possible candidate afterglow
  23. GRB090113: XRT position
  24. GRB 090112: Fermi GBM detection
  25. GRB 090107B: Swift-XRT detection of possible afterglow
  26. GRB 090107: Swift detection of a burst
  27. GRB 081228, Swift-BAT refined analysis
  28. GRB 081228: Swift-XRT Team refined analysis
  29. GRB 081226: Swift-XRT refined analysis
  30. GRB 081226A: Swift UVOT Upper Limits
  31. GRB 081226: Gemini-South spectrum of possible afterglow
  32. GRB 081226: Swift detection of a possible short-hard burst
  33. GRB 081211B: Further Swift-XRT analysis
  34. Possible GRB 081211B: Swift/UVOT Upper Limits
  35. Possible GRB 081211B - Swift-XRT analysis
  36. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  37. GRB 081211: Swift-BAT refined analysis
  38. GRB 081210: Swift-BAT refined analysis
  39. GRB 081128: optical observation in CrAO
  40. GRB 081204: Swift XRT afterglow candidate
  41. GRB 081203B: Swift-XRT candidate afterglow.
  42. GRB 081130B: MASTER prompt optical observations
  43. GRB 081128: optical observation
  44. GRB 081130B: Fermi GBM detection
  45. GRB 081128A: optical observations
  46. Trigger 335971: Swift possible detection of a burst
  47. GRB081128 : Lulin optical follow-ups
  48. GRB 081128: Swift detection of a burst
  49. GRB 081126: Confirmation of the Optical Afterglow
  50. Fermi GBM detection of a weak source
  51. GRB 081118: optical afterglow candidate
  52. GRB 081109A: confirmation of possible detection host galaxy
  53. GRB 081024B: Swift-XRT late-time observations
  54. Swift-BAT refined analysis of trigger 334129
  55. GRB 081109A: Possible Swift-UVOT detection
  56. GRB 081109A: Faulkes Telescope South observations
  57. GRB 081109A: Swift-XRT refined analysis
  58. Swift-BAT Trigger 334129: possible burst
  59. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  60. GRB 081024B: new Swift-XRT observations
  61. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  62. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  63. GRB 081025: TLS upper limits
  64. GRB 081024B: Swift-XRT further observations
  65. GRB 081025: Swift-XRT position
  66. GRB 081024B: Swift-XRT observations
  67. GRB 081024: Swift-XRT refined analysis
  68. Swift detection of a possible burst (trigger 332287)
  69. GRB 081011: Swift XRT refined analysis
  70. GRB 081016: Swift-XRT candidate afterglow detection
  71. GRB 081007 and GRB 081007B: Fermi GBM detection
  72. GRB 081003A: Swift-XRT Team position and analysis
  73. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  74. GRB080928: Gemini-South Absorption Redshift
  75. Swift detection of a possible GRB (trigger 325707)
  76. GRB 080916C: Swift/XRT detection of possible afterglow
  77. GRB 080916B: Swift UVOT Refined Analysis
  78. GRB 080905B: Refined UVOT Analysis
  79. GRB 080906: Swift detection of a burst with optical afterglow
  80. GRB 080905B: Swift detection of a burst with possible optical counterpart
  81. SGR 0501+4516: preliminary results of the first XMM-Newton observation
  82. SGR 0501+4516: Detection of possible optical counterpart
  83. SGR 0501+4516: WHT observations of the possible near-infrared counterpart
  84. GRB 080828: Swift-XRT detection of a possible X-ray afterglow
  85. Swift trigger 322590: BAT detection of a possible burst
  86. Enhanced Swift-XRT position of SGR 0501+4516
  87. SGR 0501+4516: GMRT Radio Observation at 618 MHz
  88. SGR 0501+4516: Swift XRT measure of the spin period
  89. SGR 0501+4516: Astrotel-Caucasus optical observations
  90. SGR 0501+4516: UKIRT detection of possible infra-red counterpart
  91. GRB 080822 (SGR 0501+4516): archival optical observations
  92. GRB 080810: KANATA optical-NIR observation, update
  93. GRB080804: Gemini South redshift confirmation
  94. GRB 080805: GROND detection of possible afterglow
  95. GRB 080727A: Swift-XRT refined analysis
  96. Retraction of Swift Trigger 317393
  97. Trigger 317393: Swift detection of a possible GRB
  98. GRB 080710: TLS observations, steepening afterglow decay
  99. GRB 080707: possible break in the X-rays
  100. Trigger 315630: Swift detection of a possible burst

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