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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"

28039 results found.

  1. GRB021004: NIR and Optical observations
  2. GRB 021004: Optical observations, AUDE network
  3. GRB 021004 - VLA Radio Observations
  4. GRB 021004 - Unusual Radio-to-Submm Spectrum
  5. GRB 021004: optical spectroscopy
  6. IPN triangulation of GRB021007 (annulus)
  7. GRB021004: optical observations and predicted break time
  8. GRB021004: BVRc photometry
  9. GRB021004 radio observation
  10. HETE fluences for GRB021004
  11. GRB 021004: Optical Photometry at 2.5 Days
  12. GRB 021004: polarimetric observations
  13. GRB 021004: V-band Polarimetric Observations
  14. GRB021004: Update Bisei photometric data
  15. IRAM Millimeter detection of GRB 021004
  16. GRB 021004 radio observation
  17. GRB 021004: Optical Photometry at 1.5 Days
  18. GRB021004, BVRcIc field photometry
  19. GRB021004: Optical Spectroscopy
  20. GRB 021004 radio search
  21. XRF020903, BVRI field photometry
  22. XRF020903: TNG and Asiago photometry
  23. GRB 020903: Optical observations at RIKEN
  24. XRF 020903: Correction to GCN 1560
  25. XRF 020903: VRI observations
  26. XRF 020903: R band observations
  27. XRF 020903: Archival Optical Images
  28. Radio Observations of XRF 020903: The Missing Link
  29. XRF 020903: Supernova
  30. IPN triangulation of GRB020923 (two error boxes)
  31. IPN triangulation of GRB020914B
  32. IPN triangulation of GRB020911 (2 large error boxes)
  33. GRB 020305: HST/STIS observations
  34. Confirmation of IPN error box for GRB020910
  35. IPN triangulation of GRB020910
  36. IPN GCN Circulars now to be issued without restriction
  37. Single IPN error box for GRB020904
  38. XRF 020903: optical observation at Kyoto
  39. GRB020322 : HST/STIS observations
  40. XRF 020903: Optical observations
  41. IPN triangulation of GRB020904
  42. INTEGRAL GRBs added to GCN
  43. SGR1900+14 burst localized by HETE
  44. GRB020813: High-resolution optical spectroscopy
  45. GRB020812: negative optical observations
  46. GRB 020812: optical observation at Kyoto University
  47. Second epoch K band imaging of GRB 020819
  48. GRB 020813 : HST observations
  49. GRB 020812: early time optical observation at Ouda Station
  50. GRB020813: Magellan BVRI Photometry
  51. GRB 020819: Optical observations
  52. K band observation of GRB 020819
  53. GRB020813: optical and NIR observations
  54. GRB020813: Fading X-ray Afterglow Observed with Chandra
  55. GRB020813, UBVRI field calibration
  56. GRB020812: NIR observations
  57. Polarimetry of GRB020813: evidence for variability
  58. GRB020813 IRAM millimeter observations
  59. GRB020812: optical observations
  60. GRB020813: High-Resolution Optical Observations
  61. GRB 020812: optical observation at Bisei
  62. GRB020813: Early Time Magnitude
  63. Millimeter observation of GRB 020813
  64. GRB020812: optical observations
  65. GRB 020813 : KISO multiband optical observations
  66. GRB020813, optical observations
  67. IPN error box for GRB020813
  68. GRB020813, astrometric position
  69. Spectropolarimetry of GRB 020813
  70. GRB 020812 optical observation
  71. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  72. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  73. HST Imaging of the Host of GRB 011121
  74. GRB020801, optical afterglow candidate
  75. GRB020331: Late-time Optical Light Curve (re-submission)
  76. GRB020331: Late-time Optical Light Curve
  77. IPN triangulation of GRB020714
  78. IPN triangulation of GRB020715 (=GRB150702)
  79. IPN triangulation of GRB020714
  80. IPN triangulation of GRB150702
  81. GRB 020410: Discovery of Probable OT by HST
  82. GRB 020124, HST observations of the fading afterglow
  83. IPN triangulation of GRB020708
  84. IPN triangulation of GRB020708
  85. Correction to IPN error box for GRB020706
  86. IPN triangulation of GRB020706
  87. GRB 020705: Optical observations
  88. GRB 020625, optical observations
  89. GRB 020625: Optical observations
  90. GRB 020531: optical photometry of Chandra sources
  91. GRB020625 (=H2081): A Long Burst Localized by HETE
  92. The Probable Host Galaxy of GRB/XRF 020427
  93. GRB/XRF 020427, detection of an underlying system with the VLT
  94. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  95. AXP 1E2259+586 optical observations
  96. Fading Optical Source in the Field of GRB020531
  97. GRB 020531, INT+WFC deep optical upper limits
  98. SGR-like Bursts from the AXP 1E 2259+586
  99. GRB020405: polarimetric observations
  100. GRB 020531, simultaneous optical observations

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