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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"

2803 results found.

  1. GRB 031203: IR REM Observations
  2. IPN triangulation of GRB031107 (two large error boxes)
  3. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  4. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  5. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  6. XRF 030824: additional observations at CFHT
  7. IPN detection of continued activity from SGR1806-20
  8. XRF 030824: observations at CFHT
  9. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  10. GRB030922 triangulation (annulus)
  11. GRB030913: OT's limit by MASTER
  12. GRB 030913, optical candidate
  13. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  14. GRB030913 (=H2849): TAROT Observations
  15. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  16. IPN triangulation of GRB030908 (annulus)
  17. IPN detection of continued activity from SGR1806-20
  18. SGR 1808-20 (=H2802): A Possible new SGR
  19. XRF030723: Re-analysis of ROTSE-III early images
  20. GRB030725, possible optical transient
  21. RXTE PCA Observations of SGR1806-20 Region
  22. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  23. MASTER: optical observation GRB030601
  24. GRB 030329: Correction to GCN 2254
  25. GRB 030329: Optical Observations
  26. GRB 030329/SN 2003dh: Possible increase in brightness
  27. GRB 021004: HST observations
  28. IPN triangulation of GRB030518B (annulus)
  29. GRB030429: RTT150 optical observations, a possible host galaxy
  30. GRB 030501: TAROT possible candidate counterpart
  31. GRB030429, possible optical counterpart
  32. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  33. Optical Observations of GRB 030418 with Magellan
  34. IPN triangulation of GRB030422C (annulus)
  35. GRB 030329: SARA Optical Observations
  36. OT GRB 030329: early spectrum
  37. IPN triangulation of GRB030410 (annulus)
  38. GRB 030329, color evolution
  39. GRB030329: Optical observcations
  40. GRB 030329: possible color change
  41. OT GRB light curves and SN predictions
  42. GRB 030329: fitting parameters and re-brightening
  43. GRB 030329: optical observations
  44. 030331 NOT A GRB
  45. GRB030329: ROTSE network observes steepening of decay curve
  46. GRB 030329: optical observations
  47. GRB 030329 follow-up
  48. Possible GRB030323 localized by INTEGRAL
  49. IPN triangulation of GRB030325 (final analysis)
  50. IPN triangulation of GRB030325 (two small error boxes)
  51. GRB030323, ROTSE-III detection of possible optical counterpart
  52. GRB030324, BVRcIc field photometry
  53. GRB030323, possible optical counterpart
  54. GRB030323, BVRcIc field calibration
  55. Possible GRB 030320 localized by INTEGRAL
  56. IPN triangulation of GRB030306 (two small error boxes)
  57. GRB 030226: Ic Observations
  58. GRB 030227 optical afterglow
  59. 030302: NOT A GRB
  60. 030228: NOT A GRB
  61. GRB 030227, possible optical counterpart of XMM-Newton source
  62. GRB030227 - faint tentative OT candidate
  63. Possible break in the GRB 030226 light curve
  64. GRB 030217: Optical Observations at 4, 5, and 6 Days
  65. IPN triangulation of GRB030206 (annulus)
  66. GRB030131: Candidate Optical Afterglow
  67. IPN triangulation of GRB030117 (two large error boxes)
  68. Publicizing GRB Discoveries - A Message from NASA HQ
  69. GRB 030115 : Possible IR counterpart
  70. GRB030115: TAROT optical observations
  71. Possible GRB030113 seen by SPI ACS
  72. Probable GRB030112B seen by SPI ACS
  73. Possible GRB030111 seen by SPI ACS
  74. Possible GRB030110b seen by SPI ACS
  75. Possible GRB 030110 seen by SPI ACS
  76. Possible GRB 20030109 seen by SPI ACS
  77. Possible GRB20030107 seen by SPI-ACS
  78. Possible GRB 20030105 seen by SPI ACS
  79. IPN triangulation of GRB030101 (two large error boxes)
  80. GRB 021211, optical observations
  81. IPN detection of renewed activity from SGR1806-20
  82. IPN triangulation of GRB021125B (two large error boxes)
  83. IPN triangulation of GRB021119 (large error box)
  84. GRB021125 : A long GRB localized by INTEGRAL
  85. IPN detection of possible reactivation of SGR1900+14
  86. GRB021104: optical observations
  87. GRB021104: possible optical afterglow
  88. IPN triangulation of GRB021020
  89. GRB 021004: VRI observations at TNG: possible break
  90. IPN triangulation of GRB021013 (two small error boxes)
  91. IPN triangulation of GRB021013 (annulus)
  92. XRF 020903: flattening of the optical light curve.
  93. GRB021004, UBVRcIc field photometry update
  94. IPN triangulation of GRB021007 (annulus)
  95. GRB 021004: polarimetric observations
  96. GRB 021004: Optical Observations
  97. XRF020903: TNG and Asiago photometry
  98. XRF 020903: R band observations
  99. XRF 020903: Archival Optical Images
  100. IPN triangulation of GRB020926 (two large error boxes)

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