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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"

20514 results found.

  1. GRB100814A: Magellan Echellette Observations
  2. GRB 100814A: Swift UVOT observations of the optical afterglow
  3. GRB 100814A: ROTSE-III Detection of Optical Counterpart
  4. GRB 100805A: the 4-th epoch of SAO RAS optical observations
  5. GRB 100802A: further NOT observation
  6. GRB 100805A: Swift/UVOT Observations of a Possible Late-Time Brightening
  7. GRB 100807A: P200 Infrared Observations
  8. GRB 100805A: the 3-rd epoch of SAO RAS optical observations
  9. GRB 100805A: 2-nd epoch of SAO RAS optical observations
  10. GRB 100807A: P60 Optical Afterglow Discovery
  11. GRB 100807A: Swift/UVOT Upper Limits
  12. GRB 100805A: SAO RAS optical observations
  13. GRB 100805A: IAC80 and 1.5m OSN optical observations
  14. GRB 100805A: Xinglong TNT optical observation
  15. GRB 100805A: Early RAPTOR Observations
  16. GRB 100805A: Swift/UVOT Observations of the Optical Afterglow
  17. GRB 100802A: WIYN observations
  18. GRB 100805A: IAC80 BVR-band observations
  19. GRB 100805A: GRAS 002 optical observations
  20. GRB 100805A: I-band detection from 1.23m CAHA telescope.
  21. GRB 100805A: Liverpool Telescope afterglow observations
  22. GRB 100805A: Further P60 Monitoring
  23. GRB 100805A: P60 Optical Afterglow Candidate
  24. GRB 100713A: second epoch Maidanak optical observation
  25. GRB 100802A: NOT optical observation
  26. GRB 100802A: P60 Observations
  27. GRB 100802A: Swift/UVOT Possible Optical Afterglow
  28. GRB 100802A: Liverpool Telescope observations
  29. GRB 100728B: Swift/UVOT Observations (correction to GCN 11028)
  30. GRB 100728B: Swift/UVOT Observations (correction)
  31. GRB 100728B - NOT optical observation
  32. GRB 100728B: Swift/UVOT Observations
  33. GRB 100728B: Lick Observations
  34. GRB 100728B: Continued KAIT observations
  35. GRB 100728A: GROND Detection of the NIR Afterglow Candidate
  36. GRB 100727A: Swift/UVOT Upper Limits
  37. GRB 100728A, Swift-BAT refined analysis
  38. GRB 100728A: Swift/UVOT Upper Limits
  39. GRB 100728B: GROND Detection of the NIR Afterglow
  40. GRB 100728B: Skynet/PROMPT Detections (correction)
  41. GRB 100728A: Skynet/PROMPT Detections
  42. GRB 100727A, Swift-BAT refined analysis
  43. GRB 100725A: GROND upper limits
  44. GRB 100725B: Swift/UVOT Upper Limits
  45. GRB 100725A: Swift/UVOT Upper Limits
  46. GRB100725B: Faulkes Telescope North observations
  47. GRB100725A Faulkes Telescope South observations
  48. GRB 100724A: Swift/BAT spectral lag results
  49. GRB 100724A: Swift/UVOT observations
  50. GRB 100724A: X-shooter redshift
  51. GRB 100724A, GROND detection of an afterglow candidate
  52. GRB 100614A: 10.4-m GTC deep-optical limit
  53. GRB 100718A: MASTER-Net optical prompt and alert observations
  54. GRB 100719A: Swift detection of a burst
  55. GRB 100713A: optical observation in Maidanak
  56. GRB100713A: Swift/UVOT observations
  57. GRB 100713A: GROND upper limits
  58. GRB 100713A: TNG optical observations
  59. GRB 100713A: TELMA and 1.5m OSN optical observations
  60. GRB100713A: Swift X-ray afterglow detection
  61. GRB 100628A: Keck/LRIS Spectroscopy of Host Galaxy Candidate
  62. GRB 100628A: Near-IR sources coincident with the possible X-ray afterglow
  63. GRB 100628A: Chandra observations
  64. GRB 100704: Swift/UVOT Upper Limits
  65. GRB 100615A: Additional Gemini/NIRI observations
  66. Swift/UVOT observations of GRB100702A - correction
  67. Swift/UVOT observations of GRB100702A
  68. GRB 100702A: Second epoch of Magellan near-IR observations and afterglow limits
  69. GRB 100702A: Magellan near-IR observations
  70. GRB 100702A: VLT optical observations
  71. XRF 100701A : MAXI/GSC detection of a probable XRF
  72. GRB 100213B: Detection of Fading Optical Afterglow
  73. GRB 100628A: Second epoch of Magellan near-IR observations
  74. GRB 100628A: GROND optical/NIR observations of the host candidate
  75. GRB 100628A: Gemini North Observations
  76. GRB 100628A: Coincidence of source "G1" with revised XRT error circle
  77. GRB100625A: GROND confirmation of constant source
  78. GRB 100625A Gemini-South 2nd epoch imaging
  79. GRB 100628A: Magellan near-IR observations
  80. GRB 100628A: Swift/UVOT Upper Limits
  81. GRB100628A: RTT150 optical observations
  82. GRB 100625A: Magellan near-IR Observations
  83. GRB 100625A: Swift/UVOT Upper Limits
  84. GRB 100625A: Gemini candidate afterglow
  85. GRB 100418A: late time optical observations
  86. GRB 100621A: Swift/UVOT observations
  87. GRB 100621A: VLT/X-shooter redshift
  88. GRB 100621A: GROND observation of bright NIR afterglow
  89. GRB 100619A: Swift/UVOT Upper Limits
  90. GRB 100614A: Gemini/NIRI Observations
  91. GRB 100615A: Gemini/NIRI Observations
  92. XRF 100616a : MAXI/GSC detection of a probable XRF
  93. GRB 100615A: Swift/UVOT Upper Limits
  94. GRB 100614A: Swift/UVOT Upper Limits
  95. GRB 100614A: NOT optical upper limits
  96. GRB 100614A: MASTER-Net optical alert observations
  97. GRB 100615A: GROND observations, upper limits
  98. GRB 100615A: PAIRITEL NIR Upper Limits
  99. GRB 100614A: WHT I-band observations
  100. GRB 100614A: BOOTES-2/TELMA optical observations

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