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"

32495 results found.

  1. GRB 021201: Optical Observations
  2. GRB 021211, optical observations
  3. GRB 021211: CTIO observations
  4. GRB021211: Measurement of Early Time Afterglow
  5. VLT spectrum of GRB 021211
  6. GRB 021211: early break in light curve
  7. GRB021211, BVRI field photometry
  8. GRB021211: Optical observations in CrAO
  9. GRB 021211, IR observations
  10. GRB 021211, optical observations
  11. GRB 021211: Optical Observations
  12. GRB021211: Kiso Observations
  13. GRB 021201, optical observations
  14. GRB 021211: Radio Observations
  15. GRB021211: Optical observations
  16. GRB 021201 (short/hard), NOT observations
  17. SUB-MM SEARCH FOR GRB 021211
  18. Chandra observation of the IPN error box of GRB021201 (short/hard)
  19. GRB 021211, R- and I-band observations
  20. GRB021211 - Upper limits from recent and historical observations
  21. GRB021211, OT at 108 s
  22. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  23. HETE 2493: Optical observations
  24. GRB 021125: Radio Observations
  25. IPN triangulation of GRB021206 (small error box)
  26. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  27. GRB021201, BVRcIc field photometry
  28. GRB 021201, Radio Observations
  29. GRB 021201: Optical Observations
  30. GRB 021201: BOOTES simultaneous optical observations
  31. GRB021004, late time optical observations
  32. GRB021004 Chandra Observation
  33. GRB021125 refined position
  34. IPN triangulation of GRB021125B (two large error boxes)
  35. IPN triangulation of GRB021119 (large error box)
  36. Improved IPN error box for GRB021125
  37. IPN BURST POSITION
  38. IPN confirmation of the reactivation of SGR1900+14
  39. GRB021113, SPI ACS observation
  40. GRB 021112: Afterglow or Variable Star?
  41. GRB021113: optical observations at Bisei
  42. GRB 021113: Evidence for a Dark Optical Afterglow
  43. GRB 021112: Variable Source in R-band search
  44. GRB021112: Optical Observations
  45. IPN triangulation of GRB021109 (portion of annulus)
  46. IPN triangulation of GRB021113 (=H2449; annulus)
  47. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  48. GRB 021113: Optical Observations
  49. GRB 021113: Optical Observations
  50. GRB021113 (=H2449): A Long GRB Localized by HETE
  51. GRB 021112: Optical Observations
  52. GRB 021112: R-band search
  53. IPN triangulation of GRB021108 (large error box)
  54. GRB021112 (=H2448): A Long GRB Localized by HETE
  55. GRB 021016: Optical Observations
  56. GRB021004: Near infrared spectroscopy
  57. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  58. Spectropolarimetry of GRB021004
  59. GRB021104: optical observations
  60. GRB021104: Candidate present in DSS
  61. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  62. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  63. IPN triangulation of GRB021025 (portion of annulus)
  64. IPN triangulation of GRB021027 (single large error box)
  65. GRB021004, late-time optical observations
  66. IPN triangulation of GRB021027 (two large error boxes)
  67. GRB 021023: Infrared Imaging
  68. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  69. IPN triangulation of SGR1900+14, October 22 2002
  70. GRB 021004: optical observations
  71. GRB021004: Optical Observations
  72. GRB 020813; likely host galaxy.
  73. IPN triangulation of GRB021020 (smaller error box)
  74. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  75. GRB 021008, radio observations
  76. GRB 021016, optical observations
  77. GRB 021004: VRI observations at TNG: possible break
  78. GRB021016, optical observations
  79. GRB 021008, optical observations
  80. GRB021016(=H2397): A Long GRB Localized by HETE
  81. IPN triangulation of GRB021016 (area corrected)
  82. IPN triangulation of GRB021016 (small error box)
  83. GRB021004: Optical Observations
  84. IPN triangulation of GRB021013 (single error box)
  85. GRB 021004: optical spectroscopy on Oct 11
  86. IPN triangulation of GRB021013 (two small error boxes)
  87. GRB021004: High-resolution optical spectroscopy
  88. XRF 020903: flattening of the optical light curve.
  89. GRB021004, UBVRcIc field photometry update
  90. IPN triangulation of GRB021008 (single error box)
  91. GRB021004: Optical Observations
  92. GRB 021004 submm observations
  93. IPN triangulation of GRB021008 (two small error boxes)
  94. GRB 021004: Optical/NIR Observations
  95. GRB 021004: Additional V-band Polarimetric Observations
  96. GRB021004: optical observation
  97. GRB 021004: Host Galaxy Star Formation Rate
  98. GRB 021004 submm observations
  99. GRB 021004: WC wind?
  100. GRB021004: NIR and Optical observations

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