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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"

35152 results found.

  1. GRB 060206: Lick 3m Spectroscopy
  2. GRB 060204A: ROSAT Pointing
  3. GRB 060206: Super-LOTIS observations
  4. GRB060204A: Swift/UVOT observations
  5. GRB 060206: Swift-BAT refined analysis
  6. GRB 060206 : Lulin optical observations
  7. GRB060206: SDSS Pre-Burst Observations
  8. GRB060206: Swift XRT Refined Analysis
  9. GRB060206: Liverpool Telescope observation
  10. GRB 060206: Spectroscopic Redshift
  11. GRB060206: P60 Optical Observations
  12. GRB 060206: KAIT observations
  13. GRB060206: Swift XRT Position
  14. GRB060206: SARA Detection
  15. GRB 060206: RAPTOR observations of afterglow candidate variability.
  16. GRB 060206: High redshift burst
  17. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  18. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  19. BAT GRB 060204C is probably not a GRB
  20. GRB060204C: optical observation
  21. GRB 060204B: BVRi-band detections of optical afterglow
  22. GRB 060204A: Swift XRT upper limit
  23. GRB 060204A: FRAM optical observations
  24. GRB060204B: Swift/UVOT refined analysis
  25. GRB 060204C: optical observations
  26. Swift XRT Observation of GRB 060204C
  27. GRB 060204B: Swift-BAT refined analysis
  28. GRB 060204B: ART early limit
  29. GRB060204B: Swift XRT Team Refined Analysis
  30. GRB 060204C: OSN limits
  31. GRB 060204b: Keck/LRIS Afterglow Confirmation
  32. GRB 060204C: BOOTES-IR optical limits
  33. GRB 060204C: Liverpool Telescopes optical limit
  34. GRB 060204C: ROTSE-III Optical Limits
  35. GRB 060204C: Swift-BAT detection of a burst
  36. GRB 060124: Radio Observations
  37. GRB060204B: Faulkes OT candidate
  38. GRB 060204B: ART optical limit
  39. GRB 060204A: further INTEGRAL results
  40. GRB060204B - SDSS pre-burst observations
  41. GRB 060203: Swift-BAT refined analysis
  42. GRB 060204B: Swift detection of a burst
  43. GRB 060204: a long GRB detected by INTEGRAL
  44. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  45. GRB 060203: RTT150 optical observations
  46. GRB060203: Swift XRT Team Refined Analysis
  47. Swift-BAT trigger is GRB 060203
  48. GRB 060203: IR Counterpart
  49. GRB060203: Observations with SARA
  50. GRB 060203: P60 Confirmation of Optical Afterglow
  51. Possible GRB 060203: candidate optical counterpart
  52. Possible GRB 060203: optical observations at Asiago
  53. GRB 060202: PROMPT Observations
  54. GRB 060202: GETS observation
  55. GRB 060202: Gemini-N J, H, K_s observations
  56. GRB 060202 : Kiso B and R band limit
  57. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  58. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  59. GRB 060202: Refined analysis of the Swift-BAT burst
  60. GRB 060202: Swift/UVOT upper limits
  61. GRB 060202: Swift XRT Team Refined Analysis
  62. GRB 060202 : Lulin R and I band limit
  63. GRB060202: Faulkes North observation
  64. GRB 060202: Swift detection of a burst
  65. GRB 060121: Gemini Late-time Observations
  66. Erratum: SDSS pre-burst observations of GRB fields
  67. GRB 060130: PROMPT Observations
  68. GRB 060130: Swift/XRT observation
  69. GRB 051211A: MDM Observations
  70. GRB 060123: Gemini spectroscopy of the putative host galaxy
  71. GRB 060123: VLA Radio Observations
  72. GRB060130: Optical imaging
  73. GRB060130: REM infrared observations
  74. GRB 060130, SMARTS optical observations
  75. GRB 060130: FRAM optical observations
  76. GRB 060130: further INTEGRAL IBIS results
  77. GRB 060130: a long GRB detected with INTEGRAL
  78. Possible GRB 051221B: MDM Correction
  79. GRB050121: optical observation
  80. GRB050121b: optical observation
  81. GRB 060121: Confirmation of NIR Afterglow
  82. GRB060124: optical observation
  83. GRB060124: optical observations
  84. GRB 060123: Swift refined analysis of an unusual GRB
  85. GRB060124, BVRcIc field calibration
  86. GRB060105: refined analysis of the Suzaku observation
  87. GRB060124 optical observations
  88. GRB 060121: Probable Detection of NIR Afterglow
  89. GRB060124: optical observation
  90. GRB 060116 HST observations
  91. GRB 060124: HETE detection and spectrum of the main peak
  92. Refined XRT Position for GRB 060123
  93. Konus-Wind observation of GRB 060124
  94. GRB060124: detailed XRT analysis
  95. GRB 060124 Optical Observations
  96. GRB 060124: ART optical limits during the burst
  97. GRB060123: Optical and IR Imaging
  98. GRB 060123: P200 Observations
  99. GRB 060124: Keck optical spectrum
  100. GRB 060124: Keck Absorption Redshift

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