Skip to main content
Circulars over Kafka event name backfill. 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"

24664 results found.

  1. GRB 030226, optical observations
  2. XMM-Newton observation of GRB030227
  3. GRB030227: Kiso optical observations
  4. GRB 030227: Kyoto optical observation
  5. GRB 030226, optical light curve
  6. GRB030227 localized by INTEGRAL
  7. GRB 030226 : Predicted light curve
  8. GRB030226: ESI spectroscopy
  9. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  10. GRB 030226 simultaneous optical observations
  11. GRB 030226, optical observations
  12. GRB030226: Optical decay index
  13. GRB 030226 Optical Spectra and R,I,z' Imaging
  14. GRB: Non-Referencing of GCN Circulars.
  15. IPN triangulation of GRB030217 (small error box)
  16. GRB 030131: marginal optical detection
  17. GRB 030204: Optical Observations
  18. GRB030204 field photometry
  19. GRB020819: Kiso R and I band observations
  20. GRB030131: Candidate Optical Afterglow
  21. IPN triangulation of GRB030204 (small error box)
  22. GRB 030131, optical observations
  23. GRB 030131: afterglow candidate
  24. GRB 030115, late-time optical observations
  25. GRB030131: corrected INTEGRAL position
  26. GRB 020819: Host galaxy at Radio Position
  27. IPN triangulation of GRB030131
  28. GRB 030131 optical observations
  29. GRB 030131 optical observations
  30. A long GRB detected by INTEGRAL
  31. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  32. GRB 030115, simultaneous observations by BOOTES-1
  33. GRB 030115: IR observations with IRSF/SIRIUS
  34. IPN triangulation of GRB030115C (large error box)
  35. GRB030115, afterglow candidate
  36. GRB 021211: R-band observations at late-time
  37. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  38. GRB 030115 : Possible IR counterpart
  39. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  40. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  41. GRB 030115: APO Optical Observations
  42. Information about where HETE will be pointing
  43. VLT spectroscopy of the probable host of GRB 021211
  44. IPN triangulation of GRB030101 (two large error boxes)
  45. GRB 021211: Probable Host and Underlying Supernova
  46. GRB 021112: Evidence for Another Dark Optical Afterglow
  47. GRB 021219: OSN optical observations
  48. GRB021219, optical observations
  49. GRB021219, optical observation by MASTER
  50. VLT spectra of GRB 021211 revisited
  51. GRB021219: a long GRB localized by INTEGRAL
  52. GRB021211: APO optical observations
  53. XRF 020903 : HST observations
  54. GRB 021201: Optical Observations
  55. GRB 021211: CTIO observations
  56. GRB021211, BVRI field photometry
  57. GRB021211: Optical observations in CrAO
  58. GRB 021211, optical observations
  59. GRB021211: Kiso Observations
  60. GRB 021201, optical observations
  61. GRB021211: Optical observations
  62. GRB 021201 (short/hard), NOT observations
  63. SUB-MM SEARCH FOR GRB 021211
  64. Chandra observation of the IPN error box of GRB021201 (short/hard)
  65. GRB 021211, R- and I-band observations
  66. GRB021211 - Upper limits from recent and historical observations
  67. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  68. IPN triangulation of GRB021206 (small error box)
  69. IPN triangulation of GRB021205 (large error box)
  70. GRB021201, BVRcIc field photometry
  71. GRB 021201: BOOTES simultaneous optical observations
  72. IPN triangulation of GRB021201 (short/hard burst, small error box)
  73. GRB021004, late time optical observations
  74. GRB021004 Chandra Observation
  75. IPN detection of continued SGR1900+14 activity
  76. Improved IPN error box for GRB021125
  77. IPN BURST POSITION
  78. IPN triangulation of GRB021125 (INTEGRAL BURST)
  79. GRB021125 : A long GRB localized by INTEGRAL
  80. IPN confirmation of the reactivation of SGR1900+14
  81. GRB021113, SPI ACS observation
  82. GRB 021112: Afterglow or Variable Star?
  83. GRB021113: optical observations at Bisei
  84. GRB 021113: Evidence for a Dark Optical Afterglow
  85. GRB021112, BVRI field photometry
  86. GRB 021112: Variable Source in R-band search
  87. GRB021112: Optical Observations
  88. IPN triangulation of GRB021113 (=H2449; annulus)
  89. GRB 021113: Optical observations
  90. GRB 021112: RAPTOR Observations
  91. GRB021113 (=H2449): A Long GRB Localized by HETE
  92. GRB021112 (=H2448): A Long GRB Localized by HETE
  93. GRB 021016: Optical Observations
  94. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  95. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  96. SGR1900+14 activity, November 2-4, 2002
  97. GRB021104: optical observations
  98. Detection of activity from SGR 1900+14 with the RXTE/PCA
  99. IPN triangulation of GRB021027 (single large error box)
  100. IPN triangulation of GRB021027 (two large error boxes)

Advanced

Download all Circulars as a .tar.gz archive:
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