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"

20978 results found.

  1. GRB 040106: Optical observations
  2. GRB031220: Palomar Observations
  3. GRB 031203 I-band monitoring
  4. GRB 2974 follow-up observations
  5. GRB 031203: SMARTS optical monitoring
  6. XMM-Newton Observations of GRB031203: Preliminary Images
  7. GRB 031203: Variable Radio Source
  8. GRB 031203: Magellan spectrum of possible GRB host
  9. GRB 031203: Deep NIR NTT & VLT observations
  10. GRB 031203: Radio detection
  11. GRB 031203: Further reports on December 4 observations
  12. GRB 031203: IR NTTobservations do not confirm REM detection
  13. GRB 031203: Apparent Spectral Break
  14. GRB 031203: IR REM Observations
  15. GRB031203: Optical Observations
  16. GRB 031203: Optical/IR SMARTS Observations
  17. GRB031111A, prompt optical observations
  18. GRB 031111, Radio observations
  19. GRB 031111: Optical observations
  20. GRB 031111, optical observations
  21. SN 2003jd (SN/GRB?) -- X-ray Observations
  22. XRF031109 (=H2919): A very long XRF localized by HETE
  23. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  24. Lulin optical follow-up observations of GRB031026
  25. SN 2003jd (SN/GRB?), Radio Observations
  26. GRB 031026: Further Ic Observations
  27. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  28. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  29. GRB 031026: Ic Observations
  30. GRB030329: radio observations at RT-22 (CrAO)
  31. XRF 030824: additional observations at CFHT
  32. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  33. IPN detection of continued activity from SGR1806-20
  34. XRF 030723: Subaru Optical Observations
  35. XRF 030824: observations at CFHT
  36. GRB030913: Subaru Optical Observations
  37. GRB 030913: ROTSE-3c Optical Observations
  38. GRB030913, candidate afterglow observations
  39. GRB 030913, optical candidate
  40. GRB030913: AAVSO optical observations
  41. GRB 030913, BOOTES observations
  42. GRB030913 (=H2849): Confirmation of the Flight Localization
  43. GRB030913 (=H2849): TAROT Observations
  44. Magellan Observations of GRB030725 (=H2779)
  45. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  46. XRF030824: Optical observations
  47. IBAS detection of bursts from SGR 1806-20
  48. Radio Observations of SGR1806-20
  49. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  50. XRF030824: Second-epoch Palomar observations
  51. XRF030824: optical observations
  52. GRB030823: optical observations
  53. GRB030823: Palomar observations
  54. XRF030824: Palomar observations
  55. RAPTOR observations of GRB030823
  56. Lulin follow-up observations of GRB030823
  57. IPN detection of continued activity from SGR1806-20
  58. GRB 030817 = H2808 TAROT optical observations
  59. SGR 1808-20 (=H2802): A Possible new SGR
  60. GRB 021206 Optical Observations
  61. XRF 030723: Detection of a rebrightening in the optical afterglow
  62. GRB030725: Optical observations
  63. GRB021206 optical counterpart upper limit
  64. XRF030723: Re-analysis of ROTSE-III early images
  65. XRF030723 (=H2777): Second Epoch Magellan Observations
  66. GRB 030725: optical observations.
  67. GRB030725, optical transient observations
  68. XRF030723 Radio Observations
  69. XRF 030723: confirmation of fading optical counterpart
  70. XRF030723(=H2777): Chandra Observations
  71. XRF 030723: VLT spectra
  72. Magellan Observations of XRF030723 (=H2777)
  73. GRB030723: Upper limits from historical observations
  74. GRB030725, possible optical transient
  75. XRF030723: Palomar observations and proposed counterpart
  76. XRF030723: optical observations
  77. XRF030723 (= H2777): Chandra Observations Scheduled
  78. XRF030723, ROTSE-III Early Observations
  79. XRF030723, BVRcIc field photometry
  80. XRF 030723, optical observations
  81. XRF030723, optical observations
  82. XRF 030723, optical observations
  83. GRB030723, optical observations
  84. Konus-Wind detection of the bursts from SGR1806-20 region
  85. SGR 1806-20, submm observations
  86. RXTE PCA Observations of SGR1806-20 Region
  87. GRB030329: RTT150 optical observations
  88. GRB030329, optical observation in May
  89. GRB030418: R optical observations
  90. GRB 021206, Radio afterglow candidate
  91. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  92. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  93. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  94. GRB 030528: Optical Observations
  95. GRB 030528, radio observations
  96. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  97. GRB030329, further radio observations at GMRT
  98. GRB030329, SPM optical observations
  99. GRB030528: Chandra TOO Planned
  100. GRB 030519B: 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