Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

36146 results found.

  1. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  2. Distribution of INTEGRAL SPI-ACS triggers
  3. GRB030115: R-band observations at Asiago
  4. GRB030115: TAROT optical observations
  5. GRB 021211: VLT spectrum
  6. GRB 030115: APO Optical Observations
  7. GRB 030115, no optical candidate
  8. GRB 030115, optical observations
  9. GRB 030115, optical candidate
  10. Possible GRB030113 seen by SPI ACS
  11. Probable GRB030112B seen by SPI ACS
  12. Probable GRB030112 seen by SPI ACS
  13. Possible GRB030111 seen by SPI ACS
  14. Possible GRB030110b seen by SPI ACS
  15. Possible GRB 030110 seen by SPI ACS
  16. IPN triangulation of GRB030109 (annulus)
  17. IPN triangulation of GRB030105 (large error box)
  18. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  19. Possible GRB 20030109 seen by SPI ACS
  20. IPN triangulation of GRB030102B (portion of annulus)
  21. IPN triangulation of GRB030102A (large error box)
  22. Possible GRB20030107 seen by SPI-ACS
  23. Possible GRB 20030105 seen by SPI ACS
  24. IPN triangulation of GRB030102 (annulus)
  25. GRB on 20030102 seen by SPI-ACS
  26. VLT spectroscopy of the probable host of GRB 021211
  27. GRB on 20030101 seen by SPI-ACS
  28. IPN triangulation of GRB030101 (two large error boxes)
  29. GRB021226
  30. GRB 021211: Probable Host and Underlying Supernova
  31. GRB 021226 registration by Helicon/Coronas-F
  32. Probable GRB in INTEGRAL SPI-ACS
  33. IPN triangulation of GRB021223 (two large error boxes)
  34. GRB021211, radio observations
  35. GRB 021112: Evidence for Another Dark Optical Afterglow
  36. GRB 021219: OSN optical observations
  37. GRB021219: Radio Observations
  38. IPN triangulation of GRB021219 - CORRECTION
  39. IPN triangulation of GRB021219
  40. GRB021219, optical observation by MASTER
  41. GRB021219: Correction to GCN 1766
  42. VLT spectra of GRB 021211 revisited
  43. GRB021219: a long GRB localized by INTEGRAL
  44. IPN detection of continued activity from SGR1806-20
  45. IPN triangulation of GRB021215 (large error box)
  46. IPN triangulation of GRB021214 (annulus)
  47. XRF 020903 : HST observations
  48. GRB 021201: Optical Observations
  49. GRB 021211, optical observations
  50. GRB 021211: CTIO observations
  51. GRB021211: Measurement of Early Time Afterglow
  52. VLT spectrum of GRB 021211
  53. IPN triangulation of GRB021211B (two large error boxes)
  54. GRB 021211: early break in light curve
  55. GRB021211, BVRI field photometry
  56. GRB 021211, IR observations
  57. GRB 021211, optical observations
  58. GRB 021211: Optical Observations
  59. GRB021211: Kiso Observations
  60. GRB021204: Kiso Observations
  61. GRB 021201, optical observations
  62. GRB 021211: Radio Observations
  63. GRB 021201 (short/hard), NOT observations
  64. SUB-MM SEARCH FOR GRB 021211
  65. GRB 021211 Milagro GeV/TeV Observations
  66. GRB 021211, R- and I-band observations
  67. GRB021211 - Upper limits from recent and historical observations
  68. GRB 021204: I-band Observations
  69. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  70. HETE 2493: Optical observations
  71. GRB 021204: Optical Observations at RIKEN
  72. GRB 021125: Radio Observations
  73. IPN triangulation of GRB021206 (small error box)
  74. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  75. IPN detection of renewed activity from SGR1806-20
  76. IPN triangulation of GRB021205 (large error box)
  77. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  78. GRB021201, BVRcIc field photometry
  79. GRB 021201, Radio Observations
  80. GRB 021201: Optical Observations
  81. GRB 021201: BOOTES simultaneous optical observations
  82. IPN triangulation of GRB021201 (short/hard burst, small error box)
  83. Radio Catalog of GRB Afterglows
  84. GRB021004, late time optical observations
  85. GRB021004 Chandra Observation
  86. IPN detection of continued SGR1900+14 activity
  87. IPN triangulation of GRB021115 (annulus)
  88. IPN triangulation of GRB021125B (two large error boxes)
  89. IPN triangulation of GRB021119 (large error box)
  90. IPN triangulation of GRB021125B (annulus)
  91. Improved IPN error box for GRB021125
  92. IPN triangulation of GRB021125 (INTEGRAL BURST)
  93. GRB021125 : A long GRB localized by INTEGRAL
  94. IPN confirmation of the reactivation of SGR1900+14
  95. IPN detection of possible reactivation of SGR1900+14
  96. GRB021113, SPI ACS observation
  97. IPN triangulation of GRB021119 (annulus)
  98. GRB 021112: Afterglow or Variable Star?
  99. GRB021113: optical observations at Bisei
  100. GRB 021113: Evidence for a Dark Optical Afterglow

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov