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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"

32510 results found.

  1. GRB 021211: Probable Host and Underlying Supernova
  2. GRB 021226 registration by Helicon/Coronas-F
  3. GRB 021112: Evidence for Another Dark Optical Afterglow
  4. GRB 021219: OSN optical observations
  5. GRB021219: Radio Observations
  6. GRB021219, optical observations
  7. IPN triangulation of GRB021219 - CORRECTION
  8. IPN triangulation of GRB021219
  9. GRB021219, optical observation by MASTER
  10. GRB021219: Correction to GCN 1766
  11. VLT spectra of GRB 021211 revisited
  12. GRB021219: a long GRB localized by INTEGRAL
  13. GRB021211: APO optical observations
  14. IPN detection of continued activity from SGR1806-20
  15. XRF 020903 : HST observations
  16. GRB 021201: Optical Observations
  17. GRB 021211, optical observations
  18. GRB 021211: CTIO observations
  19. GRB021211: Measurement of Early Time Afterglow
  20. VLT spectrum of GRB 021211
  21. GRB 021211: early break in light curve
  22. GRB021211, BVRI field photometry
  23. GRB021211: Optical observations in CrAO
  24. GRB 021211, IR observations
  25. GRB 021211, optical observations
  26. GRB 021211: Optical Observations
  27. GRB021211: Kiso Observations
  28. GRB 021201, optical observations
  29. GRB 021211: Radio Observations
  30. GRB021211: Optical observations
  31. GRB 021201 (short/hard), NOT observations
  32. SUB-MM SEARCH FOR GRB 021211
  33. Chandra observation of the IPN error box of GRB021201 (short/hard)
  34. GRB 021211, R- and I-band observations
  35. GRB021211 - Upper limits from recent and historical observations
  36. GRB021211, OT at 108 s
  37. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  38. HETE 2493: Optical observations
  39. GRB 021125: Radio Observations
  40. IPN triangulation of GRB021206 (small error box)
  41. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  42. GRB021201, BVRcIc field photometry
  43. GRB 021201, Radio Observations
  44. GRB 021201: Optical Observations
  45. GRB 021201: BOOTES simultaneous optical observations
  46. GRB021004, late time optical observations
  47. GRB021004 Chandra Observation
  48. GRB021125 refined position
  49. IPN triangulation of GRB021125B (two large error boxes)
  50. IPN triangulation of GRB021119 (large error box)
  51. Improved IPN error box for GRB021125
  52. IPN BURST POSITION
  53. IPN confirmation of the reactivation of SGR1900+14
  54. GRB021113, SPI ACS observation
  55. GRB 021112: Afterglow or Variable Star?
  56. GRB021113: optical observations at Bisei
  57. GRB 021113: Evidence for a Dark Optical Afterglow
  58. GRB 021112: Variable Source in R-band search
  59. GRB021112: Optical Observations
  60. IPN triangulation of GRB021109 (portion of annulus)
  61. IPN triangulation of GRB021113 (=H2449; annulus)
  62. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  63. GRB 021113: Optical Observations
  64. GRB 021113: Optical Observations
  65. GRB021113 (=H2449): A Long GRB Localized by HETE
  66. GRB 021112: Optical Observations
  67. GRB 021112: R-band search
  68. IPN triangulation of GRB021108 (large error box)
  69. GRB021112 (=H2448): A Long GRB Localized by HETE
  70. GRB 021016: Optical Observations
  71. GRB021004: Near infrared spectroscopy
  72. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  73. Spectropolarimetry of GRB021004
  74. GRB021104: optical observations
  75. GRB021104: Candidate present in DSS
  76. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  77. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  78. IPN triangulation of GRB021025 (portion of annulus)
  79. IPN triangulation of GRB021027 (single large error box)
  80. GRB021004, late-time optical observations
  81. IPN triangulation of GRB021027 (two large error boxes)
  82. GRB 021023: Infrared Imaging
  83. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  84. IPN triangulation of SGR1900+14, October 22 2002
  85. GRB 021004: optical observations
  86. GRB021004: Optical Observations
  87. GRB 020813; likely host galaxy.
  88. IPN triangulation of GRB021020 (smaller error box)
  89. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  90. GRB 021008, radio observations
  91. GRB 021016, optical observations
  92. GRB 021004: VRI observations at TNG: possible break
  93. GRB021016, optical observations
  94. GRB 021008, optical observations
  95. GRB021016(=H2397): A Long GRB Localized by HETE
  96. IPN triangulation of GRB021016 (area corrected)
  97. IPN triangulation of GRB021016 (small error box)
  98. GRB021004: Optical Observations
  99. IPN triangulation of GRB021013 (single error box)
  100. GRB 021004: optical spectroscopy on Oct 11

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