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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"

42254 results found.

  1. GRB021219, optical observation by MASTER
  2. GRB021219 refined position with INTEGRAL
  3. GRB021219: a long GRB localized by INTEGRAL
  4. GRB021211: APO optical observations
  5. XRF 020903 : HST observations
  6. GRB 021201: Optical Observations
  7. GRB 021211, optical observations
  8. GRB 021211: CTIO observations
  9. GRB021211: Measurement of Early Time Afterglow
  10. VLT spectrum of GRB 021211
  11. GRB 021211: early break in light curve
  12. GRB021211, BVRI field photometry
  13. GRB021211: Optical observations in CrAO
  14. GRB 021211, IR observations
  15. GRB 021211, optical observations
  16. GRB 021211: Optical Observations
  17. GRB021211: Kiso Observations
  18. GRB021204: Kiso Observations
  19. GRB 021201, optical observations
  20. GRB 021211: Radio Observations
  21. GRB021211: Optical observations
  22. GRB 021201 (short/hard), NOT observations
  23. GRB 021211 Milagro GeV/TeV Observations
  24. GRB 021211, R- and I-band observations
  25. GRB021211 - Upper limits from recent and historical observations
  26. GRB021211, OT at 108 s
  27. GRB 021204: I-band Observations
  28. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  29. HETE 2493: Optical observations
  30. HETE 2493: Optical observations
  31. HETE 2493: Optical candidate
  32. GRB 021204: Optical Observations at RIKEN
  33. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  34. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  35. GRB021201, BVRcIc field photometry
  36. GRB 021201: Optical Observations
  37. GRB 021201: BOOTES simultaneous optical observations
  38. IPN triangulation of GRB021201 (short/hard burst, small error box)
  39. GRB021004, late time optical observations
  40. GRB021004 Chandra Observation
  41. IPN detection of continued SGR1900+14 activity
  42. Improved IPN error box for GRB021125
  43. IPN triangulation of GRB021125 (INTEGRAL BURST)
  44. GRB021125 : A long GRB localized by INTEGRAL
  45. IPN confirmation of the reactivation of SGR1900+14
  46. GRB021113, SPI ACS observation
  47. GRB 021112: Afterglow or Variable Star?
  48. GRB021113: optical observations at Bisei
  49. GRB 021113: Evidence for a Dark Optical Afterglow
  50. GRB021112, BVRI field photometry
  51. GRB 021112: Variable Source in R-band search
  52. GRB021112: Optical Observations
  53. GRB021113: Kiso Observations
  54. GRB 021113: Optical observations
  55. GRB 021112: RAPTOR Observations
  56. GRB 021113: Optical Observations
  57. GRB 021113: Optical Observations
  58. GRB021113 (=H2449): A Long GRB Localized by HETE
  59. GRB 021112: Optical Observations
  60. GRB 021112: R-band search
  61. IPN triangulation of GRB021108 (large error box)
  62. GRB021112 (=H2448): A Long GRB Localized by HETE
  63. GRB 021016: Optical Observations
  64. IPN triangulation of GRB021109 (annulus)
  65. GRB021104: Optical Observations
  66. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  67. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  68. Spectropolarimetry of GRB021004
  69. GRB021104: Optical observations
  70. GRB021104: optical observations
  71. GRB021104: Candidate present in DSS
  72. GRB021104: possible optical afterglow
  73. Detection of activity from SGR 1900+14 with the RXTE/PCA
  74. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  75. GRB021004, late-time optical observations
  76. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  77. IPN triangulation of GRB021025 (annulus)
  78. GRB 021004: optical observations
  79. GRB021004: Optical Observations
  80. GRB 020813; likely host galaxy.
  81. IPN triangulation of GRB021020 (smaller error box)
  82. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  83. GRB 021016, optical observations
  84. GRB 021004: VRI observations at TNG: possible break
  85. GRB021016, optical observations
  86. SGR1900+14: burst on October 10 2002
  87. GRB 021008, optical observations
  88. GRB021016(=H2397): A Long GRB Localized by HETE
  89. IPN triangulation of GRB021016 (small error box)
  90. GRB021004: Optical Observations
  91. GRB 021004: optical spectroscopy on Oct 11
  92. IPN triangulation of GRB021013 (two small error boxes)
  93. GRB021004: High-resolution optical spectroscopy
  94. IPN triangulation of GRB021013 (annulus)
  95. XRF 020903: flattening of the optical light curve.
  96. GRB021004, UBVRcIc field photometry update
  97. GRB021004: Optical Observations
  98. GRB 021004 submm observations
  99. IPN triangulation of GRB021008B (annulus)
  100. GRB021004 Chandra HETG Observations

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