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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"

2707 results found.

  1. GRB040106: optical observations with REM+ROSS
  2. IPN triangulation of GRB031219 (large error box)
  3. GRB 031203: Magellan spectrum of possible GRB host
  4. GRB 031203: IR NTTobservations do not confirm REM detection
  5. GRB 031203: IR REM Observations
  6. IPN triangulation of GRB031107 (two large error boxes)
  7. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  8. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  9. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  10. XRF 030824: additional observations at CFHT
  11. IPN detection of continued activity from SGR1806-20
  12. XRF 030824: observations at CFHT
  13. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  14. GRB030922 triangulation (annulus)
  15. GRB030913: OT's limit by MASTER
  16. GRB 030913, optical candidate
  17. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  18. GRB030913 (=H2849): TAROT Observations
  19. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  20. IPN triangulation of GRB030908 (annulus)
  21. IPN detection of continued activity from SGR1806-20
  22. SGR 1808-20 (=H2802): A Possible new SGR
  23. XRF030723: Re-analysis of ROTSE-III early images
  24. GRB030725, possible optical transient
  25. RXTE PCA Observations of SGR1806-20 Region
  26. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  27. MASTER: optical observation GRB030601
  28. GRB 030329: Correction to GCN 2254
  29. GRB 030329: Optical Observations
  30. GRB 030329/SN 2003dh: Possible increase in brightness
  31. GRB 021004: HST observations
  32. IPN triangulation of GRB030518B (annulus)
  33. GRB030429: RTT150 optical observations, a possible host galaxy
  34. GRB 030501: TAROT possible candidate counterpart
  35. GRB030429, possible optical counterpart
  36. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  37. Optical Observations of GRB 030418 with Magellan
  38. IPN triangulation of GRB030422C (annulus)
  39. GRB 030329: SARA Optical Observations
  40. OT GRB 030329: early spectrum
  41. IPN triangulation of GRB030410 (annulus)
  42. GRB 030329, color evolution
  43. GRB030329: Optical observcations
  44. GRB 030329: possible color change
  45. OT GRB light curves and SN predictions
  46. GRB 030329: fitting parameters and re-brightening
  47. GRB 030329: optical observations
  48. 030331 NOT A GRB
  49. GRB030329: ROTSE network observes steepening of decay curve
  50. GRB 030329: optical observations
  51. GRB 030329 follow-up
  52. Possible GRB030323 localized by INTEGRAL
  53. IPN triangulation of GRB030325 (final analysis)
  54. IPN triangulation of GRB030325 (two small error boxes)
  55. GRB030323, ROTSE-III detection of possible optical counterpart
  56. GRB030324, BVRcIc field photometry
  57. GRB030323, possible optical counterpart
  58. GRB030323, BVRcIc field calibration
  59. Possible GRB 030320 localized by INTEGRAL
  60. IPN triangulation of GRB030306 (two small error boxes)
  61. GRB 030226: Ic Observations
  62. GRB 030227 optical afterglow
  63. 030302: NOT A GRB
  64. 030228: NOT A GRB
  65. GRB 030227, possible optical counterpart of XMM-Newton source
  66. GRB030227 - faint tentative OT candidate
  67. Possible break in the GRB 030226 light curve
  68. GRB 030217: Optical Observations at 4, 5, and 6 Days
  69. IPN triangulation of GRB030206 (annulus)
  70. GRB030131: Candidate Optical Afterglow
  71. IPN triangulation of GRB030117 (two large error boxes)
  72. Publicizing GRB Discoveries - A Message from NASA HQ
  73. GRB 030115 : Possible IR counterpart
  74. GRB030115: TAROT optical observations
  75. Possible GRB030113 seen by SPI ACS
  76. Probable GRB030112B seen by SPI ACS
  77. Possible GRB030111 seen by SPI ACS
  78. Possible GRB030110b seen by SPI ACS
  79. Possible GRB 030110 seen by SPI ACS
  80. Possible GRB 20030109 seen by SPI ACS
  81. Possible GRB20030107 seen by SPI-ACS
  82. Possible GRB 20030105 seen by SPI ACS
  83. IPN triangulation of GRB030101 (two large error boxes)
  84. GRB 021211, optical observations
  85. IPN detection of renewed activity from SGR1806-20
  86. IPN triangulation of GRB021125B (two large error boxes)
  87. IPN triangulation of GRB021119 (large error box)
  88. GRB021125 : A long GRB localized by INTEGRAL
  89. IPN detection of possible reactivation of SGR1900+14
  90. GRB021104: optical observations
  91. GRB021104: possible optical afterglow
  92. IPN triangulation of GRB021020
  93. GRB 021004: VRI observations at TNG: possible break
  94. IPN triangulation of GRB021013 (two small error boxes)
  95. IPN triangulation of GRB021013 (annulus)
  96. XRF 020903: flattening of the optical light curve.
  97. GRB021004, UBVRcIc field photometry update
  98. IPN triangulation of GRB021007 (annulus)
  99. GRB 021004: polarimetric observations
  100. GRB 021004: Optical Observations

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