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"

5157 results found.

  1. GCN GRB OBSERBATION REPORT
  2. GRB040825B: Correction to GCN 2657
  3. XRF 040812: optical observation at VLT
  4. XRF040701: Second-Epoch Chandra Observations
  5. XRF040701: First-Epoch Chandra Observations
  6. GRB040624, optical observations
  7. MASTER: GRB 040624 optical observation after 0,48d
  8. GRB 040624 - A long GRB detected with INTEGRAL
  9. IPN Summary of SGR1806-20 Activity in 2004
  10. SGR 1806-20, potential NIR counterpart
  11. GRB 040403: Optical Observations
  12. GRB 040403: Optical observations
  13. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  14. GRB040323: NIR Observations and Variable Object
  15. GRB 040323, a dark GRB ?
  16. GRB040223: Deep NIR NTT data re-analysis
  17. IBAS results on a burst from SGR1806-20
  18. GRB 040228 Optical observations
  19. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  20. GRB 040223: REM IJK Observations
  21. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  22. GRB 031220: Optical observations of Chandra X-ray sources
  23. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  24. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  25. IPN triangulation of GRB031219 (large error box)
  26. GRB031220: Palomar Observations
  27. IPN triangulation of GRB031201 (large error box)
  28. IPN triangulation of GRB031111 (=H2924): small error box
  29. IPN triangulation of GRB031108 (large error box)
  30. IPN triangulation of GRB031026B (large error box)
  31. IPN triangulation of GRB030922B (large error box)
  32. XRF 030723: Detection of the likely host galaxy
  33. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  34. GRB030913: Subaru Optical Observations
  35. GRB030913: AAVSO optical observations
  36. GRB 030913: Optical limit at RIKEN
  37. XRF030824: Optical observations
  38. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  39. XRF030824: optical observations
  40. XRF030723: optical observations
  41. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  42. IPN triangulation of GRB030715 (two large error boxes)
  43. GRB030329: second XMM-Newton observation
  44. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  45. GRB 030329: optical observations
  46. GRB 030329: optical photometry at Belesta observatory (France)
  47. GRB030329, Optical observations
  48. GRB030329: XMM-Newton observation
  49. GRB030324: Further Observations of the Candidate Optical Afterglow
  50. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  51. GRB 030418: Second Epoch Optical Observations with Magellan
  52. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  53. GRB 030429: confirmation of afterglow candidate
  54. GRB030329, SPM optical observations
  55. GRB 030329, the review of the sky area in plate archive (1950-1998)
  56. GRB 030329: Spectral Evolution of SN 2003dh
  57. GRB030329: VR Photometry at TNG
  58. GRB030324: Candidate Optical Afterglow
  59. IPN triangulation of GRB050403 (small error box)
  60. GRB030329: final R-band light curve by MASTER
  61. GRB 030329, BRI photometry
  62. GRB 030329: Additional Mt. Laguna Optical Observations
  63. GRB 030329: Correction to GCN 2056
  64. GRB 030329: fitting parameters and re-brightening
  65. GRB 030329: optical observations
  66. GRB 030324, optical search
  67. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  68. GRB030324 optical observation
  69. Possible GRB030323 localized by INTEGRAL
  70. GRB030323: Detection on 2003/03/24
  71. IPN triangulation of GRB030325 (single small error box)
  72. GRB030324, optical observations
  73. GRB030324, optical observations
  74. GRB030324, Optical Observations
  75. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  76. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  77. VLT/FORS2 spectra of GRB 030323
  78. GRB030323, ROTSE-III detection of possible optical counterpart
  79. GRB030323, optical observations
  80. IPN triangulation of GRB030320
  81. GRB 030227: Optical limit at RIKEN
  82. GRB 030227: Optical observations
  83. GRB030227: Kiso optical upper limit
  84. GRB 030226: Steep Decline
  85. GRB030226: Candidate optical afterglow
  86. IPN triangulation of GRB030208 (annulus)
  87. GRB 030131: afterglow candidate
  88. GRB 030115, simultaneous observations by BOOTES-1
  89. IPN triangulation of GRB030101 (two large error boxes)
  90. GRB 021211: Probable Host and Underlying Supernova
  91. IPN triangulation of GRB021219 - CORRECTION
  92. GRB 021211: CTIO observations
  93. GRB 021211: Optical Observations
  94. Chandra observation of the IPN error box of GRB021201 (short/hard)
  95. IPN detection of continued SGR1900+14 activity
  96. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  97. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  98. IPN triangulation of GRB021023 (small error boc)
  99. IPN triangulation of GRB021013 (single error box)
  100. IPN triangulation of GRB021013 (two small error boxes)

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