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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"

19042 results found.

  1. GRB 080915: REM NIR early observations
  2. GRB 080915: Swift/UVOT Upper Limits
  3. GRB 080913: Swift-XRT refined analysis
  4. GRB 080913: VLT/FORS spectrum
  5. GRB080913: Swift/UVOT Upper Limits
  6. GRB 080913, Swift-BAT refined analysis
  7. GRB 080913: VLT/FORS2 observations
  8. GRB 080913: REM NIR early observations
  9. GRB 080913: Enhanced Swift-XRT position
  10. GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
  11. GRB 080913: Swift detection of a burst
  12. GRB 080906: Watcher observations
  13. GRB 080905C: Fermi GBM detection
  14. Swift trigger 324362 (LS I +61 303 ?)
  15. GRB080905A: Swift/UVOT Upper Limits
  16. GRB 080905B: Watcher optical detection
  17. GRB 080905A: MITSuME Akeno optical upper limits
  18. GRB 080906: Refined Swift/UVOT Observations
  19. GRB 080906: Swift-XRT Refined Analysis
  20. GRB 080905A: optical afterglow
  21. GRB 080906: GROND observations of the optical/NIR afterglow
  22. GRB 080905B: Refined UVOT Analysis
  23. GRB 080905B: VLT redshift
  24. GRB 080905A: NOT and VLT observations
  25. GRB 080905B: Enhanced Swift-XRT position
  26. GRB 080906: Swift detection of a burst with optical afterglow
  27. GRB 080825C: Fermi GBM Spectral Analysis
  28. GRB080825C: Fermi-LAT observations
  29. GRB 080905B: Swift detection of a burst with possible optical counterpart
  30. GRB 080905: Swift detection of a probably-short burst
  31. GRB 080903: Swift/UVOT Observations
  32. GRB 080903: Swift-XRT Refined Analysis
  33. GRB 080903: Enhanced Swift-XRT position
  34. GRB 080903: optical observations
  35. GRB 080903: Liverpool Telescope observations
  36. GRB 080903: Optical afterglow candidate
  37. GRB 080903: TAROT Calern observatory optical observations
  38. GRB 080903: Swift detection of a burst
  39. SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
  40. SGR 0501+4516: Confirmation of the NIR counterpart
  41. GRB080828: Swift/UVOT Upper Limits
  42. SGR 0501+4516: Detection of possible optical counterpart
  43. GRB080825B: Swift/UVOT Upper Limits
  44. GRB 080828: Swift-XRT detection of a possible X-ray afterglow
  45. Swift trigger 322590: BAT detection of a possible burst
  46. SGR 0501+4516: Decline in Activity
  47. Enhanced Swift-XRT position of SGR 0501+4516
  48. SGR 0501+4516: GMRT Radio Observation at 618 MHz
  49. GRB080825C: GLAST Burst Monitor detection
  50. GRB 080825B: Swift-XRT team analysis
  51. Suzaku ToO Observation of SGR 0501+4516
  52. Radio Detection of SGR 0501+4516
  53. SGR 0501+4516: Astrotel-Caucasus optical observations
  54. SGR 0501+4516: UKIRT detection of possible infra-red counterpart
  55. SGR 0501+4516: optical observations
  56. SGR 0501+4516: Swift-BAT refined analysis of the 3 discovery events
  57. Discovery of the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
  58. GRB080818B: GLAST Burst Monitor detection
  59. GRB 080822: Swift detection of a short burst
  60. GRB080810 - optical observations
  61. GRB080810: optical observations
  62. Radio detection of GRB 080810 with the VLA
  63. GRB 080810: Swift/UVOT Refined Analysis
  64. GRB 080810: Liverpool Telescope observations
  65. GRB 080810: Kanazawa optical observation
  66. GRB 080810: OSN follow-up
  67. GRB 080810: Enhanced Swift-XRT position
  68. GRB 080810: KANATA optical-NIR observation, update
  69. GRB 080810 : optical observation with KANATA
  70. GRB 080810: Swift detection of a burst with a bright optical afterglow
  71. GRB 080723B: GROND upper limits
  72. GRB 080805: Faulkes Telescope South optical observations
  73. GRB 080804: GROND observations
  74. GRB 080727B: Late VLT imaging
  75. GRB 080805: Swift-XRT Refined Analysis
  76. GRB 080805: Swift/UVOT Upper Limits
  77. GRB 080804: Enhanced Swift-XRT position
  78. GRB 080804: Faulkes Telescope South observations
  79. GRB080805 optical limit by "Pi of the Sky"
  80. GRB 080805: Afterglow confirmation
  81. GRB 080805: GROND detection of possible afterglow
  82. GRB 080805: Swift detection of a burst
  83. GRB 080804: Swift detection of a burst with optical afterglow
  84. GRB 080802: Swift/UVOT Upper Limits
  85. GRB 080802: UVI Telescope Upper Limit
  86. GRB 080802: Swift detection of a probable burst
  87. GRB 080727B: IR photometry
  88. GRB 080727C: TAROT Calern observatory optical observations
  89. GRB 080727B: KAIT photometry and an early lightcurve break
  90. GRB 080727C: Swift/UVOT Upper Limits
  91. GRB 080727C: Liverpool Telescope observations
  92. GRB 080727A: VLT upper limits
  93. GRB 080727C: Enhanced Swift-XRT position
  94. GRB080727C: RTT150 optical observations
  95. GRB 080727C: Swift detection of a burst
  96. Swift detection of XTE J1701-407
  97. GRB 080727B: Swift/UVOT Upper Limits
  98. GRB080727A: Swift/UVOT Upper Limits
  99. GRB 080727B: Enhanced Swift-XRT position
  100. GRB 080727A: Enhanced Swift-XRT position

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