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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"

20513 results found.

  1. SUB-MM SEARCH FOR GRB 021211
  2. GRB 021211 Milagro GeV/TeV Observations
  3. GRB 021211, R- and I-band observations
  4. GRB021211 - Upper limits from recent and historical observations
  5. GRB021211, OT at 108 s
  6. GRB 021204: I-band Observations
  7. HETE 2493: Optical observations
  8. HETE 2493: Optical observations
  9. HETE 2493: Optical candidate
  10. GRB 021204: Optical Observations at RIKEN
  11. GRB 021125: Radio Observations
  12. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  13. GRB 021201, Radio Observations
  14. GRB 021201: Optical Observations
  15. GRB 021201: BOOTES simultaneous optical observations
  16. GRB021004, late time optical observations
  17. IPN detection of continued SGR1900+14 activity
  18. GRB021113, SPI ACS observation
  19. GRB021113: optical observations at Bisei
  20. GRB 021113: Evidence for a Dark Optical Afterglow
  21. GRB 021112, Radio Observations
  22. GRB 021112: Variable Source in R-band search
  23. GRB021112: Optical Observations
  24. GRB021113: Kiso Observations
  25. GRB 021113: Optical observations
  26. GRB 021112: RAPTOR Observations
  27. GRB 021113: Optical Observations
  28. GRB 021113: Optical Observations
  29. GRB 021112: Optical Observations
  30. GRB 021112: R-band search
  31. GRB 021016: Optical Observations
  32. GRB021004: Near infrared spectroscopy
  33. GRB021104: Optical Observations
  34. GRB021104: Optical observations
  35. GRB021104: optical observations
  36. Detection of activity from SGR 1900+14 with the RXTE/PCA
  37. GRB021004, late-time optical observations
  38. GRB 021004: optical observations
  39. GRB021004: Optical Observations
  40. GRB 020813; likely host galaxy.
  41. GRB 021008, radio observations
  42. GRB 021016, optical observations
  43. GRB 021004: VRI observations at TNG: possible break
  44. GRB021016, optical observations
  45. GRB 021008, optical observations
  46. GRB021004: Optical Observations
  47. GRB021004: High-resolution optical spectroscopy
  48. XRF 020903: flattening of the optical light curve.
  49. GRB021004: Optical Observations
  50. GRB 021004 submm observations
  51. GRB021004 Chandra HETG Observations
  52. GRB 021004: Optical/NIR Observations
  53. GRB 021004: Additional V-band Polarimetric Observations
  54. GRB 021004 submm observations
  55. GRB 021004: WC wind?
  56. GRB021004: NIR and Optical observations
  57. GRB 021004: Optical observations, AUDE network
  58. GRB 021004 - VLA Radio Observations
  59. GRB 021004 - Unusual Radio-to-Submm Spectrum
  60. GRB 021004: optical spectroscopy
  61. GRB 021004: HST/STIS spectroscopic observations
  62. GRB021004: optical observations and predicted break time
  63. GRB021004: BVRc photometry
  64. GRB 021004: Optical Decay
  65. GRB 021004 continued IR fading
  66. GRB 021004, spectroscopic observations
  67. GRB 021004: polarimetric observations
  68. GRB 021004: V-band Polarimetric Observations
  69. GRB021004: Update Bisei photometric data
  70. GRB 021004: Optical Decay
  71. GRB021004, Optical Observations
  72. GRB 021004: Optical observations at RIKEN
  73. GRB 021004: Optical Observations
  74. GRB021004: continued fading
  75. GRB 021004: Optical Photometry at 1.5 Days
  76. GRB021004, Optical Observations
  77. GRB 021004: Optical observations
  78. GRB 021004, optical observations
  79. GRB021004: Optical Spectroscopy
  80. GRB 021004: Optical Observations
  81. GRB 021004, SPM optical observations
  82. GRB 021004, optical observations
  83. GRB 021004: radio observations
  84. GRB 021004: steepening of the optical decay slope
  85. GRB021004: Upper limits from recent and historical observations
  86. GRB021004: optical observations at Nyrola
  87. GRB021004: optical observations at Bisei
  88. GRB021004: Optical Afterglow
  89. XRF020903: TNG and Asiago photometry
  90. GRB 020903: Optical observations at RIKEN
  91. XRF 020903: Correction to GCN 1560
  92. XRF 020903: VRI observations
  93. GRB 020903: correction to GCN 1557
  94. XRF 020903: R band observations
  95. XRF 020903: Archival Optical Images
  96. Radio Observations of XRF 020903: The Missing Link
  97. XRF 020903: Supernova
  98. GRB 020305: HST/STIS observations
  99. GRB020322 : HST/STIS observations
  100. XRF 020903: Optical observations

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