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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"

32714 results found.

  1. XRF 020903: optical observation at Kyoto
  2. GRB020322 : HST/STIS observations
  3. IPN triangulation of GRB020904
  4. IPN detection of a burst from SGR1900+14
  5. INTEGRAL GRBs added to GCN
  6. GRB020813: High-resolution optical spectroscopy
  7. GRB 020812: optical observation at Kyoto University
  8. Second epoch K band imaging of GRB 020819
  9. GRB020813, Baade 6.5m data now available
  10. GRB 020813 : HST observations
  11. Confirming no variability for GRB02081
  12. GRB020819 : Optical observations at KISO
  13. GRB 020812: early time optical observation at Ouda Station
  14. GRB020813: VRI Decay Slopes
  15. GRB 020819 : OT candidate - confirmation of non variability
  16. GRB 020819: Optical observations
  17. K band observation of GRB 020819
  18. GRB020819: optical observations
  19. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  20. IPN triangulation of GRB020819 (HETE 2275)
  21. GRB020813, UBVRI field calibration
  22. GRB 020813: addendum to GCN 1498
  23. GRB020813: optical observations at Bisei
  24. GRB020813: V-band decay slope
  25. Polarimetry of GRB020813: evidence for variability
  26. GRB020813 IRAM millimeter observations
  27. GRB020812: optical observations
  28. GRB 020812: optical observation at Bisei
  29. GRB020813: optical observations; possible host galaxy
  30. GRB 020813, radio detection
  31. GRB 020812 : optical afterglow candidate
  32. Millimeter observation of GRB 020813
  33. GRB020812: optical observations
  34. GRB 020813 : KISO multiband optical observations
  35. IPN error box for GRB020813
  36. IPN triangulation of GRB020813
  37. GRB020812: possible afterglow candidate
  38. Early Time Limits for GRB020813
  39. GRB020812: possible afterglow candidate
  40. GRB020813, astrometric position
  41. Spectropolarimetry of GRB 020813
  42. GRB 020813 Afterglow Observations; Possible break
  43. GRB 020813: Absorption redshift
  44. GRB 020813 multiband optical observations
  45. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  46. GRB 020812 optical observation
  47. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  48. GRB 020715, optical observations
  49. GRB 020714, optical observations
  50. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  51. HST Imaging of the Host of GRB 011121
  52. GRB020801, optical afterglow candidate
  53. Further refinement to IPN error box for GRB020531
  54. GRB020331: Late-time Optical Light Curve (re-submission)
  55. GRB020331: Late-time Optical Light Curve
  56. GRB 020405: HST observations reveal red bump
  57. IPN triangulation of GRB020714
  58. IPN triangulation of GRB020715 (=GRB150702)
  59. IPN triangulation of GRB020714
  60. IPN triangulation of GRB150702
  61. GRB 020410: Discovery of Probable OT by HST
  62. GRB 020124, HST observations of the fading afterglow
  63. IPN triangulation of GRB020708
  64. IPN triangulation of GRB020708
  65. IPN error box for GRB020706
  66. IPN triangulation of GRB020706
  67. GRB 020705: Optical observations
  68. GRB 020625, optical observations
  69. GRB 020625: Optical observations
  70. GRB 020531: optical photometry of Chandra sources
  71. GRB020625 (=H2081): A Long Burst Localized by HETE
  72. The Probable Host Galaxy of GRB/XRF 020427
  73. GRB/XRF 020427, detection of an underlying system with the VLT
  74. GRB 020531, INT+WFC deep optical upper limits
  75. GRB020405: polarimetric observations
  76. GRB 020531, simultaneous optical observations
  77. GRB 020604, optical observations
  78. GRB 020531/Candidate Redshift
  79. GRB020531: Second epoch Chandra observations
  80. GRB020604, optical observations
  81. GRB020604, BVRcIc field photometry
  82. GRB020603, BVRcIc field observations
  83. GRB020531, BVRcIc field photometry
  84. GRB020531 Optical observations with TAROT
  85. GRB020531 Optical observations with TAROT
  86. GRB 020418, optical/near-IR observations
  87. GRB 020531, Radio Observations
  88. IPN triangulation of GRB020604
  89. GRB020531: Observations with the Chandra X-ray Observatory
  90. GRB 020603: Optical Observations
  91. GRB 020603, R-band observation
  92. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  93. GRB 020603: Optical observations
  94. IPN triangulation of GRB020603 (possible short/hard GRB)
  95. GRB 020531 optical observations with TAROT
  96. Refined IPN error box for GRB020531
  97. GRB020531, optical observations
  98. GRB020531(=H2042): Optical Observations
  99. IPN triangulation of the short, hard GRB020531 (=H2042)
  100. GRB020531(=H2042): Optical Observations

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