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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"

16222 results found.

  1. IPN BURST POSITION
  2. IPN triangulation of GRB021125 (INTEGRAL BURST)
  3. GRB021125 : A long GRB localized by INTEGRAL
  4. GRB 021112: Afterglow or Variable Star?
  5. GRB021113: optical observations at Bisei
  6. GRB 021113: Evidence for a Dark Optical Afterglow
  7. GRB021112, BVRI field photometry
  8. GRB 021112: Variable Source in R-band search
  9. GRB021112: Optical Observations
  10. GRB 021113: Optical observations
  11. GRB 021112: RAPTOR Observations
  12. GRB 021113: Optical Observations
  13. GRB 021016: Optical Observations
  14. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  15. GRB021104: optical observations
  16. Detection of activity from SGR 1900+14 with the RXTE/PCA
  17. GRB 021004: VRI observations at TNG: possible break
  18. IPN triangulation of GRB021014 (large error box)
  19. IPN triangulation of GRB021013 (two small error boxes)
  20. XRF 020903: flattening of the optical light curve.
  21. GRB021004, UBVRcIc field photometry update
  22. GRB 021004: Optical/NIR Observations
  23. GRB 021004: Additional V-band Polarimetric Observations
  24. GRB021004: optical observation
  25. GRB 021004: Host Galaxy Star Formation Rate
  26. GRB 021004: WC wind?
  27. IPN triangulation of GRB021007 (annulus)
  28. GRB021004: BVRc photometry
  29. GRB021004 radio observation
  30. GRB 021004: Optical Photometry at 2.5 Days
  31. GRB 021004: polarimetric observations
  32. GRB 021004: V-band Polarimetric Observations
  33. GRB021004: Update Bisei photometric data
  34. GRB 021004 radio observation
  35. GRB 021004: Optical Photometry at 1.5 Days
  36. GRB021004, BVRcIc field photometry
  37. GRB 021004 radio search
  38. XRF020903, BVRI field photometry
  39. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  40. XRF020903: TNG and Asiago photometry
  41. XRF 020903: Correction to GCN 1560
  42. XRF 020903: VRI observations
  43. XRF 020903: R band observations
  44. IPN triangulation of GRB020923 (two error boxes)
  45. GRB 020305: HST/STIS observations
  46. XRF 020903: optical observation at Kyoto
  47. GRB020322 : HST/STIS observations
  48. XRF 020903: Optical observations
  49. IPN triangulation of GRB020904
  50. INTEGRAL GRBs added to GCN
  51. GRB020812: negative optical observations
  52. GRB 020812: optical observation at Kyoto University
  53. Second epoch K band imaging of GRB 020819
  54. GRB 020813 : HST observations
  55. GRB 020812: early time optical observation at Ouda Station
  56. GRB020813: Magellan BVRI Photometry
  57. GRB 020819: Optical observations
  58. K band observation of GRB 020819
  59. GRB020813: optical and NIR observations
  60. GRB020813: Fading X-ray Afterglow Observed with Chandra
  61. GRB020813, UBVRI field calibration
  62. Polarimetry of GRB020813: evidence for variability
  63. GRB020812: optical observations
  64. GRB020813: High-Resolution Optical Observations
  65. GRB020813: Early Time Magnitude
  66. GRB020812: optical observations
  67. GRB020813, optical observations
  68. GRB020813, astrometric position
  69. GRB 020812 optical observation
  70. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  71. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  72. HST Imaging of the Host of GRB 011121
  73. GRB020801, optical afterglow candidate
  74. Further refinement to IPN error box for GRB020531
  75. GRB020331: Late-time Optical Light Curve (re-submission)
  76. GRB020331: Late-time Optical Light Curve
  77. GRB 020410: Discovery of Probable OT by HST
  78. IPN triangulation of GRB020708
  79. GRB 020705: Optical observations
  80. GRB 020625, optical observations
  81. GRB 020625: Optical observations
  82. GRB 020531: optical photometry of Chandra sources
  83. GRB020625 (=H2081): A Long Burst Localized by HETE
  84. The Probable Host Galaxy of GRB/XRF 020427
  85. GRB/XRF 020427, detection of an underlying system with the VLT
  86. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  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. GRB 020604, optical observations
  93. GRB020531: Second epoch Chandra observations
  94. GRB020604, optical observations
  95. GRB020604, BVRcIc field photometry
  96. GRB020603, BVRcIc field observations
  97. GRB020531, BVRcIc field photometry
  98. GRB020531 Optical Observations
  99. GRB020531: Observations with the Chandra X-ray Observatory
  100. GRB020531, optical observations

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