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"

37736 results found.

  1. IPN triangulation of GRB030301 (annulus)
  2. IPN triangulation of GRB030228 (annulus)
  3. GRB030227, BVRcIc field photometry
  4. GRB030226, BVRcIc field calibration
  5. GRB 030227 optical afterglow
  6. 030302: NOT A GRB
  7. 030228: NOT A GRB
  8. GRB 030228, optical observations
  9. GRB 030226: Steep Decline
  10. GRB 030227: Confirmed Optical Afterglow (S1-A)
  11. GRB 030226: R band polarimetric observations
  12. GRB 030226: Optical observations
  13. GRB 030227: fading of candidate optical afterglow 'S1-A'
  14. GRB030227:Optical observations
  15. GRB 20030226: Upper limits from recent and historical observations
  16. GRB 030227, possible optical counterpart of XMM-Newton source
  17. GRB030227 - faint tentative OT candidate
  18. GRB 030226, optical observations
  19. GRB030227: Kiso optical observations
  20. GRB 030227: Kyoto optical observation
  21. GRB 030226, optical light curve
  22. GRB 030226 spectroscopy
  23. Possible break in the GRB 030226 light curve
  24. GRB 030226 : Predicted light curve
  25. IPN triangulation of GRB030225 (annulus)
  26. GRB 030226: Confirmed decay index
  27. GRB030226: ESI spectroscopy
  28. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  29. GRB 030226 simultaneous optical observations
  30. Two absorption systems in GRB 030226
  31. GRB 030226, optical observations
  32. GRB 030226 Optical Spectra and R,I,z' Imaging
  33. GRB 030226, optical observations
  34. GRB 030226: Optical afterglow
  35. GRB 030217: Optical Observations at 4, 5, and 6 Days
  36. IPN triangulation of GRB030223 (annulus)
  37. IPN triangulation of GRB030220 (annulus)
  38. GRB: Non-Referencing of GCN Circulars.
  39. IPN triangulation of GRB030218 (annulus)
  40. IPN triangulation of GRB030217 (small error box)
  41. IPN triangulation of GRB030215C (annulus)
  42. IPN triangulation of GRB030217 (annulus)
  43. IPN triangulation of GRB030216 (annulus)
  44. IPN triangulation of GRB030215A and GRB030215B (annuli)
  45. GRB030115, WSRT radio observations - correction to GCN 1864
  46. GRB 030131: marginal optical detection
  47. GRB030115, WSRT radio observations
  48. IPN triangulation of GRB030206 (annulus)
  49. IPN triangulation of GRB030208 (annulus)
  50. GRB 030204: Optical Observations
  51. GRB030204 field photometry
  52. GRB020819: Kiso R and I band observations
  53. GRB 030204: Correction to GCN 1856
  54. GRB 030115: Optical Observations
  55. GRB 030204, optical observations
  56. IPN triangulation of GRB030204 (small error box)
  57. IPN triangulation of GRB030202 (annulus)
  58. GRB 030131, optical observations
  59. GRB030131: Kiso optical limit for corrected position
  60. GRB030131: Optical limits for corrected position
  61. GRB 030131: afterglow candidate
  62. GRB 030115, late-time optical observations
  63. GRB030131: corrected INTEGRAL position
  64. Type Ic SN2003L (SN/GRB?), optical spectrum
  65. GRB030131: Kiso Observations
  66. GRB 020819: Host galaxy at Radio Position
  67. IPN triangulation of GRB030131 - CORRECTION
  68. GRB 020819: afterglow candidate
  69. IPN triangulation of GRB030131
  70. GRB 030131 optical observations
  71. GRB 030131 optical observations
  72. A long GRB detected by INTEGRAL
  73. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  74. Type Ic SN2003L (SN/GRB?) Radio Observations
  75. IPN triangulation of GRB030127 (annulus)
  76. GRB030115 submm upper limit
  77. IPN triangulation of GRB030119 (two large error boxes)
  78. GRB 030115: Further IR observations with IRSF/SIRIUS
  79. IPN triangulation of GRB030117 (two large error boxes)
  80. Publicizing GRB Discoveries - A Message from NASA HQ
  81. GRB 030115: Radio detection of IR candidate
  82. GRB 030115, simultaneous observations by BOOTES-1
  83. GRB 030115: IR observations with IRSF/SIRIUS
  84. IPN triangulation of GRB030115C (large error box)
  85. GRB030115: R-band counterpart of IR candidate
  86. GRB030115, afterglow candidate
  87. GRB 021211: R-band observations at late-time
  88. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  89. IPN triangulation of GRB030115B (small error box)
  90. GRB 030115 : Possible IR counterpart
  91. GRB 030115: Radio Observations
  92. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  93. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  94. IPN triangulation of GRB030115B (annulus)
  95. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  96. Distribution of INTEGRAL SPI-ACS triggers
  97. GRB030115: R-band observations at Asiago
  98. GRB030115: TAROT optical observations
  99. GRB 021211: VLT spectrum
  100. GRB 030115: APO 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