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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"

26537 results found.

  1. GRB 021201: Optical Observations
  2. GRB 021211: CTIO observations
  3. IPN triangulation of GRB021211B (two large error boxes)
  4. GRB021211, BVRI field photometry
  5. GRB021211: Optical observations in CrAO
  6. GRB 021211, optical observations
  7. GRB021211: Kiso Observations
  8. GRB 021201, optical observations
  9. GRB021211: Optical observations
  10. GRB 021201 (short/hard), NOT observations
  11. SUB-MM SEARCH FOR GRB 021211
  12. Chandra observation of the IPN error box of GRB021201 (short/hard)
  13. GRB 021211 Milagro GeV/TeV Observations
  14. GRB 021211, R- and I-band observations
  15. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  16. GRB 021125: Radio Observations
  17. IPN triangulation of GRB021206 (small error box)
  18. IPN triangulation of GRB021205 (large error box)
  19. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  20. GRB021201, BVRcIc field photometry
  21. GRB 021201, Radio Observations
  22. GRB 021201: Optical Observations
  23. GRB 021201: BOOTES simultaneous optical observations
  24. IPN triangulation of GRB021201 (short/hard burst, small error box)
  25. GRB021004, late time optical observations
  26. GRB021004 Chandra Observation
  27. IPN detection of continued SGR1900+14 activity
  28. GRB021125 refined position
  29. Improved IPN error box for GRB021125
  30. IPN BURST POSITION
  31. IPN triangulation of GRB021125 (INTEGRAL BURST)
  32. GRB021125 : A long GRB localized by INTEGRAL
  33. IPN confirmation of the reactivation of SGR1900+14
  34. GRB 021112: Afterglow or Variable Star?
  35. GRB021113: optical observations at Bisei
  36. GRB021112, BVRI field photometry
  37. GRB 021112: Variable Source in R-band search
  38. GRB021112: Optical Observations
  39. GRB021113: Kiso Observations
  40. GRB 021113: Optical observations
  41. GRB 021112: RAPTOR Observations
  42. GRB 021113: Optical Observations
  43. GRB021113 (=H2449): A Long GRB Localized by HETE
  44. GRB 021112: R-band search
  45. GRB021112 (=H2448): A Long GRB Localized by HETE
  46. GRB 021016: Optical Observations
  47. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  48. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  49. SGR1900+14 activity, November 2-4, 2002
  50. GRB021104: Optical observations
  51. GRB021104: optical observations
  52. GRB021104: Candidate present in DSS
  53. Detection of activity from SGR 1900+14 with the RXTE/PCA
  54. IPN triangulation of GRB021027 (single large error box)
  55. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  56. GRB 021004: optical observations
  57. IPN triangulation of GRB021023 (small error boc)
  58. IPN triangulation of GRB021020 (smaller error box)
  59. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  60. IPN triangulation of GRB021020
  61. GRB 021016, optical observations
  62. GRB 021004: VRI observations at TNG: possible break
  63. GRB 021008, optical observations
  64. GRB021016(=H2397): A Long GRB Localized by HETE
  65. IPN triangulation of GRB021016 (small error box)
  66. IPN triangulation of GRB021014 (large error box)
  67. IPN triangulation of GRB021013 (single error box)
  68. IPN triangulation of GRB021013 (two small error boxes)
  69. XRF 020903: flattening of the optical light curve.
  70. GRB021004, UBVRcIc field photometry update
  71. IPN triangulation of GRB021008 (single error box)
  72. GRB 021004 submm observations
  73. IPN triangulation of GRB021008 (two small error boxes)
  74. GRB021004 Chandra HETG Observations
  75. GRB 021004: Optical/NIR Observations
  76. GRB 021004: Additional V-band Polarimetric Observations
  77. GRB021004: optical observation
  78. GRB 021004: Host Galaxy Star Formation Rate
  79. GRB 021004 submm observations
  80. GRB 021004: WC wind?
  81. GRB021004: NIR and Optical observations
  82. GRB 021004: Optical observations, AUDE network
  83. GRB 021004 - VLA Radio Observations
  84. GRB 021004 - Unusual Radio-to-Submm Spectrum
  85. GRB 021004: optical spectroscopy
  86. IPN triangulation of GRB021007 (annulus)
  87. GRB021004: optical observations and predicted break time
  88. GRB021004: BVRc photometry
  89. GRB021004 radio observation
  90. HETE fluences for GRB021004
  91. GRB 021004: Optical Photometry at 2.5 Days
  92. GRB 021004: polarimetric observations
  93. GRB 021004: V-band Polarimetric Observations
  94. GRB021004: Update Bisei photometric data
  95. IRAM Millimeter detection of GRB 021004
  96. GRB 021004 radio observation
  97. GRB 021004: Optical Observations
  98. GRB021004: continued fading
  99. GRB 021004: Optical Photometry at 1.5 Days
  100. GRB021004, BVRcIc field photometry

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