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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"

42767 results found.

  1. Trigger 255685: Swift detection of a possible burst
  2. GRB 070110: VLT absorption redshift
  3. GRB 070110: UVOT Observations of a Candidate Afterglow
  4. GRB070110: Swift XRT Team refined analysis
  5. GRB 070110, Swift-BAT refined analysis
  6. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  7. GRB 070110: Swift detection of a burst with a possible optical afterglow
  8. IBAS Alert n. 4047: Not a GRB
  9. GRB070107: Swift/XRT refined analysis
  10. GRB 070107: Possible UVOT Afterglow
  11. GRB 070107, Swift-BAT refined analysis
  12. GRB 070107: Swift/XRT position
  13. GRB 070107: Swift detection of a burst
  14. VLA observation of GRB 061222B
  15. VLA detection of GRB 061222A
  16. GRB070103: APO SPIcam i' and z' limits
  17. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  18. GRB070103: KPNO 4m+FLAMINGOS J limit
  19. GRB 070103: Swift/UVOT Upper limits
  20. GRB070103: Swift XRT refined analysis
  21. GRB 070103, Swift-BAT refined analysis
  22. GRB 070103: NOT observations
  23. GRB 070103: TAROT Calern observatory optical observations
  24. GRB 070103: Swift detection of a burst
  25. Retractions of previous Swift-BAT triggers
  26. erratum : SDSS Pre-burst Observations of GRB061126
  27. Konus-Wind observation of GRB 061222A
  28. GRB 061210: Swift/XRT Astrometry Correction
  29. GRB 050826: MDM Redshift
  30. GRB 061222B: TAROT La Silla observatory early optical observations
  31. GRB 061218: TAROT La Silla observatory early optical observations
  32. GRB 061222A: MITSuME Akeno optical upper limits
  33. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  34. GRB 061222B: MITSuME Akeno optical upper limits
  35. GRB 061222A: Xinglong Optical Limit
  36. GRB 061222A: Gemini Afterglow Candidate
  37. GRB 061222B, Swift-BAT refined analysis
  38. GRB061222A Swift/UVOT: Upper Limits
  39. GRB 061222B: Swift/UVOT Upper limits
  40. GRB 061222B: Observation with the KANATA 1.5m telescope
  41. GRB061222B: Swift-XRT Refined Analysis
  42. GRB 061222A: Observation with the KANATA 1.5m telescope
  43. GRB 061222B: BOOTES-IR optical observations
  44. GRB 061222B: SARA upper limit
  45. GRB 061222A: Swift-XRT refined analysis
  46. GRB 061217: Magellan host galaxy redshift
  47. GRB 061222A, Swift-BAT refined analysis
  48. GRB 061222B: REM NIR/optical observations
  49. GRB 061222b, SMARTS optical/IR afterglow observations
  50. GRB 061222B: TAROT La Silla observatory optical observations
  51. GRB 061222B: Swift detection of a burst
  52. GRB 061222A: Prompt ROTSE-III Optical Limits
  53. GRB 061222: Swift detection of a burst
  54. GRB 061217: Astrometry-Corrected XRT Position
  55. GRB 061201: Magellan redshift of nearby galaxy
  56. GRB 061217: Confirmation of host candidate
  57. GRB 061217: Object ib GCN 5948 is a star
  58. GRB 061217, Candidate host galaxy
  59. GRB 061217 - Swift/XRT position correction
  60. GRB 061210: Possible Host Galaxy (S2-G2) Keck Spectrum
  61. GRB 061201: Magellan Redshift of nearby Abell cluster
  62. GRB 061218: TAROT La Silla observatory optical observations
  63. GRB 061217: TAROT Calern observatory optical observations
  64. GRB 061218: TORTOREM optical upper limits
  65. GRB061217: VLT NIR observations
  66. GRB 061218, SMARTS optical/IR observations
  67. GRB 061218: REM prompt observations
  68. Swift triggers (#251863) on a possible burst
  69. GRB 061217, SMARTS optical observations
  70. GRB061217: Swift/UVOT refined analysis.
  71. GRB 061217: optical observations at Calar Alto
  72. GRB061217 - Swift/XRT refined analysis
  73. GRB 061217, Further Swift-BAT refined analysis of the short hard burst
  74. GRB 061217: Magellan Observations
  75. GRB 061217: REM prompt observations
  76. GRB 061217: ROTSE-III Optical Limits
  77. GRB 061217: Swift detection of a short hard burst
  78. GRB 061210: MDM Follow-up Observation
  79. GRB061210: Swift/UVOT observations
  80. GRB 061210: Optical sources near XRT positions
  81. GRB 061210: Swift XRT analysis - Possible counterparts
  82. GRB 061210 : Faulkes North Telescope optical limit
  83. GRB 061214(?): ROTSE-III Optical Limits
  84. GRB 061214(?): Swift detection of a possible burst
  85. GRB 061210: Suzaku WAM observation of the prompt emission
  86. Swift/BAT trigger #250033 is due to a known source during loss of
  87. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  88. GRB 061213: MASTER-VWF-Kislovodsk observations
  89. GRB 061210: Gemini/GMOS Observations
  90. GRB 061126: Radio Observations
  91. GRB061210: Radio Observations
  92. GRB061201, VLT optical decay: correction
  93. GRB 061126: a GRB detected off-axis by INTEGRAL
  94. GRB 061202: Suzaku WAM observation of the prompt emission
  95. GRB 061210: Swift-BAT detection of a short burst
  96. Optical Afterglow observations of GRB 061126
  97. GRB061126: optical observations
  98. GRB 060926: MASTER: discovery of the optical flare
  99. Corrections for Swift/UVOT Exposure Times for GRBs 061110B and 061121
  100. GRB 061201: UVOT Observations of a Fading Optical Afterglow

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