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"

42240 results found.

  1. GRB 021211, optical observations
  2. GRB 021211: Optical Observations
  3. GRB021211: Kiso Observations
  4. GRB021204: Kiso Observations
  5. GRB 021201, optical observations
  6. GRB 021211: Radio Observations
  7. GRB021211: Optical observations
  8. GRB 021201 (short/hard), NOT observations
  9. GRB 021211 Milagro GeV/TeV Observations
  10. GRB 021211, R- and I-band observations
  11. GRB021211 - Upper limits from recent and historical observations
  12. GRB021211, OT at 108 s
  13. GRB 021204: I-band Observations
  14. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  15. HETE 2493: Optical observations
  16. HETE 2493: Optical observations
  17. HETE 2493: Optical candidate
  18. GRB 021204: Optical Observations at RIKEN
  19. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  20. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  21. GRB021201, BVRcIc field photometry
  22. GRB 021201: Optical Observations
  23. GRB 021201: BOOTES simultaneous optical observations
  24. IPN triangulation of GRB021201 (short/hard burst, small error box)
  25. GRB021004, late time optical observations
  26. GRB021004 Chandra Observation
  27. IPN detection of continued SGR1900+14 activity
  28. Improved IPN error box for GRB021125
  29. IPN triangulation of GRB021125 (INTEGRAL BURST)
  30. GRB021125 : A long GRB localized by INTEGRAL
  31. IPN confirmation of the reactivation of SGR1900+14
  32. GRB021113, SPI ACS observation
  33. GRB 021112: Afterglow or Variable Star?
  34. GRB021113: optical observations at Bisei
  35. GRB 021113: Evidence for a Dark Optical Afterglow
  36. GRB021112, BVRI field photometry
  37. GRB 021112: Variable Source in R-band search
  38. GRB021112: Optical Observations
  39. GRB021113: Kiso Observations
  40. GRB 021113: Optical observations
  41. GRB 021112: RAPTOR Observations
  42. GRB 021113: Optical Observations
  43. GRB 021113: Optical Observations
  44. GRB021113 (=H2449): A Long GRB Localized by HETE
  45. GRB 021112: Optical Observations
  46. GRB 021112: R-band search
  47. IPN triangulation of GRB021108 (large error box)
  48. GRB021112 (=H2448): A Long GRB Localized by HETE
  49. GRB 021016: Optical Observations
  50. IPN triangulation of GRB021109 (annulus)
  51. GRB021104: Optical Observations
  52. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  53. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  54. Spectropolarimetry of GRB021004
  55. GRB021104: Optical observations
  56. GRB021104: optical observations
  57. GRB021104: Candidate present in DSS
  58. GRB021104: possible optical afterglow
  59. Detection of activity from SGR 1900+14 with the RXTE/PCA
  60. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  61. GRB021004, late-time optical observations
  62. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  63. IPN triangulation of GRB021025 (annulus)
  64. GRB 021004: optical observations
  65. GRB021004: Optical Observations
  66. GRB 020813; likely host galaxy.
  67. IPN triangulation of GRB021020 (smaller error box)
  68. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  69. GRB 021016, optical observations
  70. GRB 021004: VRI observations at TNG: possible break
  71. GRB021016, optical observations
  72. SGR1900+14: burst on October 10 2002
  73. GRB 021008, optical observations
  74. GRB021016(=H2397): A Long GRB Localized by HETE
  75. IPN triangulation of GRB021016 (small error box)
  76. GRB021004: Optical Observations
  77. GRB 021004: optical spectroscopy on Oct 11
  78. IPN triangulation of GRB021013 (two small error boxes)
  79. GRB021004: High-resolution optical spectroscopy
  80. IPN triangulation of GRB021013 (annulus)
  81. XRF 020903: flattening of the optical light curve.
  82. GRB021004, UBVRcIc field photometry update
  83. GRB021004: Optical Observations
  84. GRB 021004 submm observations
  85. IPN triangulation of GRB021008B (annulus)
  86. GRB021004 Chandra HETG Observations
  87. GRB 021004: Optical/NIR Observations
  88. GRB 021004: Additional V-band Polarimetric Observations
  89. GRB021004: optical observation
  90. GRB 021004: Host Galaxy Star Formation Rate
  91. GRB 021004 submm observations
  92. GRB 021004: WC wind?
  93. IPN triangulation of GRB021008
  94. GRB021004: NIR and Optical observations
  95. GRB 021004: Optical measurement at OHP
  96. GRB 021004: Optical observations, AUDE network
  97. GRB 021004 - VLA Radio Observations
  98. GRB 021004 - Unusual Radio-to-Submm Spectrum
  99. GRB 021004: optical spectroscopy
  100. IPN triangulation of GRB021007 (annulus)

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