Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

24882 results found.

  1. GRB021113: optical observations at Bisei
  2. GRB 021113: Evidence for a Dark Optical Afterglow
  3. GRB021112, BVRI field photometry
  4. GRB 021112: Variable Source in R-band search
  5. GRB021112: Optical Observations
  6. IPN triangulation of GRB021113 (=H2449; annulus)
  7. GRB 021113: Optical observations
  8. GRB 021112: RAPTOR Observations
  9. GRB021113 (=H2449): A Long GRB Localized by HETE
  10. GRB021112 (=H2448): A Long GRB Localized by HETE
  11. GRB 021016: Optical Observations
  12. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  13. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  14. SGR1900+14 activity, November 2-4, 2002
  15. GRB021104: optical observations
  16. Detection of activity from SGR 1900+14 with the RXTE/PCA
  17. IPN triangulation of GRB021027 (single large error box)
  18. IPN triangulation of GRB021027 (two large error boxes)
  19. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  20. GRB 021004: optical observations
  21. IPN triangulation of GRB021023 (small error boc)
  22. GRB 020813; likely host galaxy.
  23. IPN triangulation of GRB021020 (smaller error box)
  24. IPN triangulation of GRB021020
  25. GRB 021008, optical observations
  26. IPN triangulation of GRB021016 (small error box)
  27. IPN triangulation of GRB021014 (large error box)
  28. IPN triangulation of GRB021013 (single error box)
  29. GRB 021004: optical spectroscopy on Oct 11
  30. IPN triangulation of GRB021013 (two small error boxes)
  31. GRB021004: High-resolution optical spectroscopy
  32. XRF 020903: flattening of the optical light curve.
  33. GRB021004, UBVRcIc field photometry update
  34. IPN triangulation of GRB021008 (single error box)
  35. GRB 021004 submm observations
  36. IPN triangulation of GRB021008 (two small error boxes)
  37. GRB021004 Chandra HETG Observations
  38. GRB 021004: Optical/NIR Observations
  39. GRB 021004: Additional V-band Polarimetric Observations
  40. GRB021004: optical observation
  41. GRB 021004: Host Galaxy Star Formation Rate
  42. GRB 021004 submm observations
  43. GRB 021004: WC wind?
  44. GRB021004: NIR and Optical observations
  45. GRB 021004: Optical observations, AUDE network
  46. GRB 021004 - VLA Radio Observations
  47. GRB 021004 - Unusual Radio-to-Submm Spectrum
  48. GRB 021004: optical spectroscopy
  49. IPN triangulation of GRB021007 (annulus)
  50. GRB021004: optical observations and predicted break time
  51. GRB021004: BVRc photometry
  52. GRB021004 radio observation
  53. HETE fluences for GRB021004
  54. GRB 021004: Optical Photometry at 2.5 Days
  55. GRB 021004: polarimetric observations
  56. GRB 021004: V-band Polarimetric Observations
  57. GRB021004: Update Bisei photometric data
  58. IRAM Millimeter detection of GRB 021004
  59. GRB 021004 radio observation
  60. GRB 021004: Optical Photometry at 1.5 Days
  61. GRB021004, BVRcIc field photometry
  62. GRB021004: Optical Spectroscopy
  63. GRB 021004 radio search
  64. XRF020903, BVRI field photometry
  65. XRF020903: TNG and Asiago photometry
  66. GRB 020903: Optical observations at RIKEN
  67. XRF 020903: Correction to GCN 1560
  68. XRF 020903: VRI observations
  69. XRF 020903: R band observations
  70. XRF 020903: Archival Optical Images
  71. Radio Observations of XRF 020903: The Missing Link
  72. XRF 020903: Supernova
  73. IPN triangulation of GRB020923 (two error boxes)
  74. IPN triangulation of GRB020914B
  75. IPN triangulation of GRB020911 (2 large error boxes)
  76. GRB 020305: HST/STIS observations
  77. Confirmation of IPN error box for GRB020910
  78. IPN triangulation of GRB020910
  79. IPN GCN Circulars now to be issued without restriction
  80. Single IPN error box for GRB020904
  81. XRF 020903: optical observation at Kyoto
  82. GRB020322 : HST/STIS observations
  83. XRF 020903: Optical observations
  84. IPN triangulation of GRB020904
  85. INTEGRAL GRBs added to GCN
  86. SGR1900+14 burst localized by HETE
  87. GRB020813: High-resolution optical spectroscopy
  88. GRB020812: negative optical observations
  89. GRB 020812: optical observation at Kyoto University
  90. Second epoch K band imaging of GRB 020819
  91. GRB 020813 : HST observations
  92. GRB 020812: early time optical observation at Ouda Station
  93. GRB020813: Magellan BVRI Photometry
  94. GRB 020819: Optical observations
  95. K band observation of GRB 020819
  96. GRB020813: optical and NIR observations
  97. GRB020813: Fading X-ray Afterglow Observed with Chandra
  98. GRB020813, UBVRI field calibration
  99. GRB020812: NIR observations
  100. Polarimetry of GRB020813: evidence for variability

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