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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"

20351 results found.

  1. GRB 021004: V-band Polarimetric Observations
  2. GRB021004: Update Bisei photometric data
  3. GRB 021004 radio observation
  4. GRB 021004: Optical Observations
  5. GRB 021004: Optical Photometry at 1.5 Days
  6. GRB021004, Optical Observations
  7. GRB021004, BVRcIc field photometry
  8. GRB 021004: Optical observations
  9. GRB 021004: optical counterpart
  10. GRB 021004, optical observations
  11. GRB 021004 radio search
  12. GRB 021004: steepening of the optical decay slope
  13. XRF020903, BVRI field photometry
  14. GRB021004: optical observations at Nyrola
  15. GRB021004: optical observations at Bisei
  16. GRB 021004: Kyoto observation
  17. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  18. XRF020903: TNG and Asiago photometry
  19. GRB 020903: Optical observations at RIKEN
  20. XRF 020903: Correction to GCN 1560
  21. XRF 020903: VRI observations
  22. GRB 020903: correction to GCN 1557
  23. XRF 020903: R band observations
  24. XRF 020903: Supernova
  25. IPN triangulation of GRB020923 (two error boxes)
  26. GRB 020305: HST/STIS observations
  27. Confirmation of IPN error box for GRB020910
  28. IPN triangulation of GRB020910
  29. Single IPN error box for GRB020904
  30. XRF 020903: optical observation at Kyoto
  31. GRB020322 : HST/STIS observations
  32. XRF 020903: Optical observations
  33. IPN triangulation of GRB020904
  34. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  35. INTEGRAL GRBs added to GCN
  36. SGR1900+14 burst localized by HETE
  37. GRB020813: High-resolution optical spectroscopy
  38. GRB020812: negative optical observations
  39. GRB 020812: optical observation at Kyoto University
  40. Second epoch K band imaging of GRB 020819
  41. GRB 020813 : HST observations
  42. GRB 020812: early time optical observation at Ouda Station
  43. GRB020813: VRI Decay Slopes
  44. GRB020813: Magellan BVRI Photometry
  45. GRB 020819: Optical observations
  46. IPN triangulation of GRB020819 (HETE 2275)
  47. GRB020813: optical and NIR observations
  48. GRB020813: Fading X-ray Afterglow Observed with Chandra
  49. GRB020813, UBVRI field calibration
  50. Polarimetry of GRB020813: evidence for variability
  51. GRB020812: optical observations
  52. GRB020813: High-Resolution Optical Observations
  53. GRB 020812: optical observation at Bisei
  54. GRB020812: optical observations
  55. GRB 020813 : KISO multiband optical observations
  56. GRB020813, optical observations
  57. IPN error box for GRB020813
  58. GRB020812: possible afterglow candidate
  59. GRB020812: possible afterglow candidate
  60. GRB020813, astrometric position
  61. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  62. GRB 020812 optical observation
  63. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  64. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  65. HST Imaging of the Host of GRB 011121
  66. GRB020801, optical afterglow candidate
  67. GRB020331: Late-time Optical Light Curve (re-submission)
  68. GRB020331: Late-time Optical Light Curve
  69. IPN triangulation of GRB020714
  70. IPN triangulation of GRB020715 (=GRB150702)
  71. IPN triangulation of GRB020714
  72. IPN triangulation of GRB150702
  73. GRB 020410: Discovery of Probable OT by HST
  74. IPN triangulation of GRB020708
  75. IPN triangulation of GRB020708
  76. Correction to IPN error box for GRB020706
  77. IPN triangulation of GRB020706
  78. GRB 020705: Optical observations
  79. GRB 020625, optical observations
  80. GRB 020625: Optical observations
  81. GRB 020531: optical photometry of Chandra sources
  82. The Probable Host Galaxy of GRB/XRF 020427
  83. GRB/XRF 020427, detection of an underlying system with the VLT
  84. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  85. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  86. AXP 1E2259+586: quasi-simultaneous optical observation
  87. AXP 1E2259+586 optical observations
  88. Fading Optical Source in the Field of GRB020531
  89. GRB 020531, INT+WFC deep optical upper limits
  90. GRB020405: polarimetric observations
  91. GRB 020531, simultaneous optical observations
  92. GRB020531: Second epoch Chandra observations
  93. GRB020604, optical observations
  94. GRB020604, BVRcIc field photometry
  95. GRB020603, BVRcIc field observations
  96. GRB020531, BVRcIc field photometry
  97. GRB020531 Optical Observations
  98. GRB020531: Observations with the Chandra X-ray Observatory
  99. IPN triangulation of GRB020603 (possible short/hard GRB)
  100. GRB020531, optical observations

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