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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"

24378 results found.

  1. GRB 251126A: Swift detection of a burst
  2. EP251124b follow-up observation by EP-FXT
  3. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  4. Fermi GRB 251125B: Global MASTER-Net observations report
  5. GRB 251125B: Fermi GBM Final Real-time Localization
  6. EP251124b: Global MASTER-Net observations report
  7. EP251124a: Xinglong GWAC-F60A optical observation
  8. Fermi GRB 251125A: Global MASTER-Net observations report
  9. GRB 251125A: Fermi GBM Final Real-time Localization
  10. EP251124a: Global MASTER-Net observations report
  11. GRB 251124A: Fermi GBM Localization by automated pipeline
  12. GRB 251122B: Fermi GBM Final Localization
  13. Fermi GRB 251124a: Global MASTER-Net observations report
  14. GRB 251124a: Fermi GBM Final Localization
  15. LIGO/Virgo/KAGRA S251105aj: SVOM/VT optical observations and preliminary results on SVOM J2320.0-2901
  16. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
  17. EP251124a: GROWTH-India Telescope optical upper limits
  18. GRB 251116C: Swift-XRT confirmation of fading
  19. GRB 251122A/EP251122a: FTW optical and NIR observations
  20. GRB 251122A/EP251122A: 1.3m DFOT optical detection
  21. The EP-WXT trigger 01709248783 is likely a flaring star
  22. GRB 251122A / EP251122a: Xinglong 2.16m optical observation
  23. EP251118A: 3.6m DOT optical afterglow detection
  24. GRB 251122A / EP251122a: EP-FXT counterpart detection
  25. EP251122a: refined analysis of the EP-WXT and EP-FXT observations
  26. GRB 251122A/EP251122a: SVOM/VT optical observations with VHF data
  27. GRB 251122A / EP251122a: LCO optical upper limits
  28. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  29. EP251122a: Global MASTER-Net observations report
  30. GRB 251122A/EP251122a: SVOM/C-GFT upper limit
  31. GRB 251122A / EP251122a: SVOM detection of a long burst
  32. LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search
  33. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  34. EP251118a: Xinglong-2.16m optical observation
  35. GRB 251115A: Fermi GBM Observation
  36. The EP-WXT trigger 01709248635 is likely a flaring star
  37. GRB 251121A: Fermi GBM Final Real-time Localization
  38. Fermi trigger No 785388351: Global MASTER-Net observations report
  39. EP251118A: 1.3m DFOT optical afterglow detection
  40. GRB 251118A: Glowbug gamma-ray detection
  41. GRB 251118A: Fermi GBM Observation
  42. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  43. GRB 251118A: GECAM-B detection
  44. EP251118a / GRB 251118C: SVOM/VT optical observation
  45. The EP-WXT trigger 01709248403 is likely a flaring star
  46. GRB 251118A: NuSTAR detection of bright prompt emission
  47. GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
  48. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  49. GRB 251117A: Swift-XRT observations
  50. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  51. Konus-Wind detection of GRB 251118C (EP251118a)
  52. GRB 251116D: SVOM/GRM observation of a long GRB
  53. GRB 251119A: SVOM detection of a possible burst
  54. EP251118a: Global MASTER-Net observations report
  55. LAT GRB251118.86: Global MASTER-Net observations report
  56. GRB 251118A: Fermi-LAT detection
  57. Fermi GRB 251118B: Global MASTER-Net observations report
  58. GRB 251118B: Fermi GBM Final Real-time Localization
  59. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  60. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  61. GRB 251118A: Fermi GBM Final Real-time Localization
  62. GRB 251116C: SVOM/ECLAIRs refined analysis
  63. GRB 251116B: SVOM/ECLAIRs refined analysis
  64. GRB 251114B: GECAM-B detection of a short burst
  65. GRB 251117A: Fermi GBM observation
  66. LIGO/Virgo/KAGRA S251117dq: Updated Sky localization
  67. GRB 251115A: Swift-XRT observations
  68. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  69. GRB 251117A: SVOM/GRM observation of a short burst
  70. GRB 251117A: Fermi-LAT detection
  71. LAT GRB251117.51: Global MASTER-Net observations report
  72. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  73. GRB 251116C: Swift/BAT arcminute localization of a burst
  74. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  75. GRB 251116B: SVOM/VT optical upper limit
  76. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  77. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  78. GRB 251117A: Fermi GBM Final Localization Correction
  79. GRB 251116D: Glowbug gamma-ray detection
  80. LIGO/Virgo/KAGRA S251112cm: EP-FXT follow-up observations
  81. GRB 251116C: SVOM/VT optical upper limit
  82. GRB 251116B: EP-FXT follow-up observation
  83. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  85. GRB 251116B: LCO optical upper limits
  86. GRB 251116C: LCO optical upper limits
  87. SVOM GRB251116C: Global MASTER-Net observations report
  88. GRB 251116C: SVOM detection of a burst
  89. GRB 251116B: SVOM detection of a burst
  90. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  91. GRB 251116A: Fermi GBM Final Real-time Localization
  92. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  93. GRB 251115A: Fermi-LAT detection
  94. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  95. Fermi GRB 251115A: Global MASTER-Net observations report
  96. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  97. GRB 251115A: Fermi GBM Final Real-time Localization
  98. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  99. GRB 251114B: Fermi GBM Final Real-time Localization
  100. GRB 251112A: Swift-BAT refined analysis

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